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| Publications of Herman Pontzer :chronological alphabetical combined listing:%% Book Sections/Chapters @misc{fds374604, Author = {Pontzer, H}, Title = {Evolutionary Changes in Physical Activity, Diet, and Energy Expenditure: Implications for the Prevention of Obesity}, Volume = {2}, Pages = {11-17}, Booktitle = {Handbook of Obesity - Volume 2: Clinical Applications, Fifth Edition}, Year = {2023}, Month = {January}, ISBN = {9781032551081}, url = {http://dx.doi.org/10.1201/9781003432807-3}, Abstract = {Obesity and related metabolic diseases are recent phenomena, products of our increasingly industrialized world. Our Paleolithic hunter-gatherer ancestors and the subsistence farming communities that succeeded them were largely protected from these diseases. Here, we discuss how our evolutionary legacy as hunter-gatherers leaves us vulnerable to obesity and cardiometabolic disease in industrialized societies. Hunting and gathering, as well as subsistence farming, require high levels of daily physical activity. Hunter-gatherer diets are remarkably variable across time and geography, but typically include a balance of plant and animal foods. Human physiology is therefore adapted to high levels of daily physical activity and a wide range of diets. The sedentary behavior and heavily processed foods typical of modern societies are evolutionarily novel and promote poor health. Exercise is essential for cardiometabolic health but is less effective as a weight loss tool, and societal changes in physical activity do not appear to have contributed substantially to the modern obesity pandemic. Instead, recent changes in diet, particularly the growing prevalence of ultra-processed foods, have likely been the primary societal drivers of the obesity pandemic.}, Doi = {10.1201/9781003432807-3}, Key = {fds374604} } @misc{fds346490, Author = {Raichlen, DA and Webber, JT and Pontzer, H}, Title = {The evolution of the human endurance phenotype}, Pages = {135-147}, Booktitle = {Routledge Handbook of Sport and Exercise Systems Genetics}, Year = {2019}, Month = {January}, ISBN = {9781138504851}, url = {http://dx.doi.org/10.4324/9781315146287-11}, Abstract = {Aerobic activities are those which can be sustained entirely by oxygen-based metabolism. The rate of oxygen consumption during an activity, called VO2, is often used as a measure of energy for aerobic activities. Activity costs tend to increase with body size, and so to account for differences in body size, energy expenditure during an activity is often expressed as metabolic equivalents, the ratio of activity energy expenditure to basal metabolic rate. Comparative biology offers a valuable methodological approach to examine evolutionary physiology in living taxa. By comparing performance or morphology in humans and our closest living relatives, the great apes can better understand how, and potentially when, major changes in evolutionary physiology occurred. Reconstructions of locomotion and behavior in the earliest hominins generally suggest that, although they walked bipedally, in many respects they more closely resemble nonhuman great apes in activity patterns and behavior.}, Doi = {10.4324/9781315146287-11}, Key = {fds346490} } %% Journal Articles @article{fds375873, Author = {Sercel, AJ and Sturm, G and Gallagher, D and St-Onge, M-P and Kempes, CP and Pontzer, H and Hirano, M and Picard, M}, Title = {Hypermetabolism and energetic constraints in mitochondrial disorders.}, Journal = {Nature metabolism}, Volume = {6}, Number = {2}, Pages = {192-195}, Year = {2024}, Month = {February}, url = {http://dx.doi.org/10.1038/s42255-023-00968-8}, Doi = {10.1038/s42255-023-00968-8}, Key = {fds375873} } @article{fds373335, Author = {Rimbach, R and Pontzer, H}, Title = {Increased physical activity is not related to markers of cardiometabolic health in two lemur species.}, Journal = {American journal of primatology}, Volume = {86}, Number = {1}, Pages = {e23564}, Year = {2024}, Month = {January}, url = {http://dx.doi.org/10.1002/ajp.23564}, Abstract = {Insufficient physical activity is a major risk factor for cardiometabolic disease (i.e., unhealthy weight gain, heart disease, and diabetes) in humans and may also negatively affect health of primates in human care. Effects of physical activity on energy expenditure and cardiometabolic health are virtually unstudied in nonhuman primates. We investigated physical activity and metabolic markers in 15 adult ring-tailed lemurs (Lemur catta) and 11 Coquerel's sifakas (Propithecus coquereli) at the Duke Lemur Center during a period of low activity in winter when the animals were housed in buildings (with outdoor access) and a period of high activity when individuals were free-ranging in large, outdoor, forested enclosures. We compared body mass, blood glucose, triglycerides, HDL- and LDL-cholesterol, physical activity via accelerometry, and total energy expenditure (TEE) via the doubly labeled water method (in ring-tailed lemurs only) between both conditions. Both species were more active and had a lower body mass in summer. Ring-tailed lemurs had a higher TEE and lower triglyceride levels in summer, whereas sifaka had higher triglyceride levels in summer. Individuals that increased their activity more, also lost more body mass. Individuals that lost more body mass, also had a positive change in HDL-cholesterol (i.e., higher values in summer). Changes in activity were not associated with changes in markers of metabolic health, body fat percentage and TEE (both unadjusted and adjusted for body composition). Older age was associated with lower activity in both species, and decreased glucose in ring-tailed lemurs, but was otherwise unrelated to metabolic markers and, for ring-tailed lemurs, adjusted TEE. Overall, body mass was lower during summer but the increase in physical activity did not strongly influence metabolic health or TEE in these populations.}, Doi = {10.1002/ajp.23564}, Key = {fds373335} } @article{fds374541, Author = {Pontzer, H}, Title = {Correction: 'A unified theory for the energy cost of legged locomotion' (2016), by Pontzer.}, Journal = {Biology letters}, Volume = {19}, Number = {12}, Pages = {20230492}, Year = {2023}, Month = {December}, url = {http://dx.doi.org/10.1098/rsbl.2023.0492}, Doi = {10.1098/rsbl.2023.0492}, Key = {fds374541} } @article{fds371433, Author = {Trumble, BC and Pontzer, H and Stieglitz, J and Cummings, DK and Wood, B and Emery Thompson and M and Raichlen, D and Beheim, B and Yetish, G and Kaplan, H and Gurven, M}, Title = {Energetic costs of testosterone in two subsistence populations.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {35}, Number = {11}, Pages = {e23949}, Year = {2023}, Month = {November}, url = {http://dx.doi.org/10.1002/ajhb.23949}, Abstract = {<h4>Objective</h4>Testosterone plays a role in mediating energetic trade-offs between growth, maintenance, and reproduction. Investments in a high testosterone phenotype trade-off against other functions, particularly survival-enhancing immune function and cellular repair; thus only individuals in good condition can maintain both a high testosterone phenotype and somatic maintenance. While these effects are observed in experimental manipulations, they are difficult to demonstrate in free-living animals, particularly in humans. We hypothesize that individuals with higher testosterone will have higher energetic expenditures than those with lower testosterone.<h4>Methods</h4>Total energetic expenditure (TEE) was quantified using doubly labeled water in n = 40 Tsimane forager-horticulturalists (50% male, 18-87 years) and n = 11 Hadza hunter-gatherers (100% male, 18-65 years), two populations living subsistence lifestyles, high levels of physical activity, and high infectious burden. Urinary testosterone, TEE, body composition, and physical activity were measured to assess potential physical and behavioral costs associated with a high testosterone phenotype.<h4>Results</h4>Endogenous male testosterone was significantly associated with energetic expenditure, controlling for fat free mass; a one standard deviation increase in testosterone is associated with the expenditure of an additional 96-240 calories per day.<h4>Discussion</h4>These results suggest that a high testosterone phenotype, while beneficial for male reproduction, is also energetically expensive and likely only possible to maintain in healthy males in robust condition.}, Doi = {10.1002/ajhb.23949}, Key = {fds371433} } @article{fds372440, Author = {Dolan, E and Koehler, K and Areta, J and Longman, DP and Pontzer, H}, Title = {Energy constraint and compensation: Insights from endurance athletes.}, Journal = {Comparative biochemistry and physiology. Part A, Molecular & integrative physiology}, Volume = {285}, Pages = {111500}, Year = {2023}, Month = {November}, url = {http://dx.doi.org/10.1016/j.cbpa.2023.111500}, Abstract = {The Constrained Model of Total Energy Expenditure predicts that increased physical activity may not influence total energy expenditure, but instead, induces compensatory energetic savings in other processes. Much remains unknown, however, about concepts of energy expenditure, constraint and compensation in different populations, and it is unclear whether this model applies to endurance athletes, who expend very large amounts of energy during training and competition. Furthermore, it is well-established that some endurance athletes consciously or unconsciously fail to meet their energy requirements via adequate food intake, thus exacerbating the extent of energetic stress that they experience. Within this review we A) Describe unique characteristics of endurance athletes that render them a useful model to investigate energy constraints and compensations, B) Consider the factors that may combine to constrain activity and total energy expenditure, and C) Describe compensations that occur when activity energy expenditure is high and unmet by adequate energy intake. Our main conclusions are as follows: A) Higher activity levels, as observed in endurance athletes, may indeed increase total energy expenditure, albeit to a lesser degree than may be predicted by an additive model, given that some compensation is likely to occur; B) That while a range of factors may combine to constrain sustained high activity levels, the ability to ingest, digest, absorb and deliver sufficient calories from food to the working muscle is likely the primary determinant in most situations and C) That energetic compensation that occurs in the face of high activity expenditure may be primarily driven by low energy availability i.e., the amount of energy available for all biological processes after the demands of exercise have been met, and not by activity expenditure per se.}, Doi = {10.1016/j.cbpa.2023.111500}, Key = {fds372440} } @article{fds372769, Author = {Sayre, MK and Anyawire, M and Paolo, B and Mabulla, AZP and Pontzer, H and Wood, BM and Raichlen, DA}, Title = {Lifestyle and patterns of physical activity in Hadza foragers.}, Journal = {American journal of biological anthropology}, Volume = {182}, Number = {3}, Pages = {340-356}, Year = {2023}, Month = {November}, url = {http://dx.doi.org/10.1002/ajpa.24846}, Abstract = {<h4>Objectives</h4>Physically active lifestyles are associated with several health benefits. Physical activity (PA) levels are low in post-industrial populations, but generally high throughout life in subsistence populations. The Hadza are a subsistence-oriented foraging population in Tanzania known for being physically active, but it is unknown how recent increases in market integration may have altered their PA patterns. In this study, we examine PA patterns for Hadza women and men who engage in different amounts of traditional foraging.<h4>Materials and methods</h4>One hundred and seventy seven Hadza participants (51% female, 19-87 years) wore an Axivity accelerometer (dominant wrist) for ~6 days during dry season months. We evaluated the effects of age, sex, and lifestyle measures on four PA measures that capture different aspects of the PA profile.<h4>Results</h4>Participants engaged in high levels of both moderate-intensity PA and inactivity. Although PA levels were negatively associated with age, older participants were still highly active. We found no differences in PA between participants living in more traditional "bush" camps and those living in more settled "village" camps. Mobility was positively associated with step counts for female participants, and schooling was positively associated with inactive time for male participants.<h4>Conclusions</h4>The similarity in PA patterns between Hadza participants in different camp types suggests that high PA levels characterize subsistence lifestyles generally. The sex-based difference in the effects of mobility and schooling on PA could be a reflection of the Hadza's gender-based division of labor, or indicate that changes to subsistence-oriented lifestyles impact women and men in different ways.}, Doi = {10.1002/ajpa.24846}, Key = {fds372769} } @article{fds372770, Author = {Best, AW and McGrosky, A and Swanson, Z and Rimbach, R and McConaughy, K and McConaughy, J and Ocobock, C and Pontzer, H}, Title = {Total Energy Expenditure and Nutritional Intake in Continuous Multiday Ultramarathon Events.}, Journal = {International journal of sport nutrition and exercise metabolism}, Volume = {33}, Number = {6}, Pages = {342-348}, Year = {2023}, Month = {November}, url = {http://dx.doi.org/10.1123/ijsnem.2023-0063}, Abstract = {Continuous multiday ultramarathon competitions are increasingly popular and impose extreme energetic and nutritional demands on competitors. However, few data have been published on energy expenditure during these events. Here, we report doubly labeled water-derived measures of total energy expenditure (in kilocalories per day) and estimated physical activity level (PAL: total energy expenditure/basal metabolic rate) collected from five elite and subelite finishers (four males and one female, age 34.6 ± 4.9 years)-and nutritional intake data from the winner-of the Cocodona 250, a ∼402-km race in Arizona, and from a fastest-known-time record (one male, age 30 years) on the ∼1,315-km Arizona Trail. PAL during these events exceeded four times basal metabolic rate (Cocodona range: 4.34-6.94; Arizona Trail: 5.63). Combining the results with other doubly labeled water-derived total energy expenditure data from ultraendurance events show a strong inverse relationship between event duration and PAL (r2 = .68, p < .0001). Cocodona race duration was inversely, though not significantly, associated with PAL (r2 = .70, p = .08). Water turnover varied widely between athletes and was not explained by PAL or body mass. The Cocodona race winner met ∼53% of energy demand via dietary intake, 85.6% of which was carbohydrate, while ∼47% of energy demand was met via catabolism of body energy stores. Together, these results illustrate the energetic deficits incurred during competitive continuous multiday ultramarathon efforts and implicate macronutrient absorption and/or storage as key factors in ultramarathon performance.}, Doi = {10.1123/ijsnem.2023-0063}, Key = {fds372770} } @article{fds372663, Author = {Pontzer, H}, Title = {The provisioned primate: patterns of obesity across lemurs, monkeys, apes and humans.}, Journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, Volume = {378}, Number = {1888}, Pages = {20220218}, Year = {2023}, Month = {October}, url = {http://dx.doi.org/10.1098/rstb.2022.0218}, Abstract = {Non-human primates are potentially informative but underutilized species for investigating obesity. I examined patterns of obesity across the Primate order, calculating the ratio of body mass in captivity to that in the wild. This index, relative body mass, for <i>n</i> = 40 non-human primates (mean ± s.d.: females: 1.28 ± 0.30, range 0.67-1.78, males: 1.24 ± 0.28, range 0.70-1.97) overlapped with a reference value for humans (women: 1.52, men: 1.44). Among non-human primates, relative body mass was unrelated to dietary niche, and was marginally greater among female cohorts of terrestrial species. Males and females had similar relative body masses, but species with greater sexual size dimorphism (male/female mass) in wild populations had comparatively larger female body mass in captivity. Provisioned populations in wild and free-ranging settings had similar relative body mass to those in research facilities and zoos. Compared to the wild, captive diets are unlikely to be low in protein or fat, or high in carbohydrate, suggesting these macronutrients are not driving overeating in captive populations. Several primate species, including chimpanzees, a sister-species to humans, had relative body masses similar to humans. Humans are not unique in the propensity to overweight and obesity. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.}, Doi = {10.1098/rstb.2022.0218}, Key = {fds372663} } @article{fds372255, Author = {Speakman, JR and Pontzer, H}, Title = {Quantifying physical activity energy expenditure based on doubly labelled water and basal metabolism calorimetry: what are we actually measuring?}, Journal = {Current opinion in clinical nutrition and metabolic care}, Volume = {26}, Number = {5}, Pages = {401-408}, Year = {2023}, Month = {September}, url = {http://dx.doi.org/10.1097/mco.0000000000000937}, Abstract = {<h4>Purpose of review</h4>Physical activity impacts energy balance because of its contribution to total energy expenditure. Measuring physical activity energy expenditure (PAEE) is often performed by subtracting the estimated 24 h expenditure on basal metabolism (called basal energy expenditure or BEE) from the total energy expenditure (TEE) measured by doubly labelled water minus an estimate of the thermic effect of food (TEF). Alternatively it can be measured as the ratio of TEE/BEE, which is commonly called the physical activity level (PAL).<h4>Recent findings</h4>PAEE and PAL are widely used in the literature but their shortcomings are seldom addressed. In this review, we outline some of the issues with their use.<h4>Summary</h4>TEE and BEE are both measured with error. The estimate of PAEE by difference magnifies these errors and consequently the precision of estimated PAEE is about 3× worse than TEE and 25-35× worse than BEE. A second problem is that the component called PAEE is actually any component of TEE that is not BEE. We highlight how the diurnal variation of BEE, thermoregulatory expenditure and elevations of RMR because of stress will all be part of what is called PAEE and will contribute to a disconnect between what is measured and what energy expenditure is a consequence of physical activity. We emphasize caution should be exerted when interpreting these measurements of PAEE and PAL.}, Doi = {10.1097/mco.0000000000000937}, Key = {fds372255} } @article{fds373008, Author = {Lea, AJ and Clark, AG and Dahl, AW and Devinsky, O and Garcia, AR and Golden, CD and Kamau, J and Kraft, TS and Lim, YAL and Martins, DJ and Mogoi, D and Pajukanta, P and Perry, GH and Pontzer, H and Trumble, BC and Urlacher, SS and Venkataraman, VV and Wallace, IJ and Gurven, M and Lieberman, DE and Ayroles, JF}, Title = {Applying an evolutionary mismatch framework to understand disease susceptibility.}, Journal = {PLoS biology}, Volume = {21}, Number = {9}, Pages = {e3002311}, Year = {2023}, Month = {September}, url = {http://dx.doi.org/10.1371/journal.pbio.3002311}, Abstract = {Noncommunicable diseases (NCDs) are on the rise worldwide. Obesity, cardiovascular disease, and type 2 diabetes are among a long list of "lifestyle" diseases that were rare throughout human history but are now common. The evolutionary mismatch hypothesis posits that humans evolved in environments that radically differ from those we currently experience; consequently, traits that were once advantageous may now be "mismatched" and disease causing. At the genetic level, this hypothesis predicts that loci with a history of selection will exhibit "genotype by environment" (GxE) interactions, with different health effects in "ancestral" versus "modern" environments. To identify such loci, we advocate for combining genomic tools in partnership with subsistence-level groups experiencing rapid lifestyle change. In these populations, comparisons of individuals falling on opposite extremes of the "matched" to "mismatched" spectrum are uniquely possible. More broadly, the work we propose will inform our understanding of environmental and genetic risk factors for NCDs across diverse ancestries and cultures.}, Doi = {10.1371/journal.pbio.3002311}, Key = {fds373008} } @article{fds368054, Author = {Swanson, ZS and Nzunza, R and Bethancourt, HJ and Saunders, J and Mutindwa, F and Ndiema, E and Braun, DR and Rosinger, AY and Pontzer, H}, Title = {Early childhood growth in Daasanach pastoralists of Northern Kenya: Distinct patterns of faltering in linear growth and weight gain.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {35}, Number = {4}, Pages = {e23842}, Year = {2023}, Month = {April}, url = {http://dx.doi.org/10.1002/ajhb.23842}, Abstract = {<h4>Objectives</h4>Investigations of early childhood growth among small-scale populations are essential for understanding human life history variation and enhancing the ability to serve such communities through global public health initiatives. This study characterizes early childhood growth trajectories and identifies differences in growth patterns relative to international references among Daasanach semi-nomadic pastoralist children living in a hot, arid region of northern Kenya.<h4>Methods</h4>A large sample of height and weight measures were collected from children (N = 1756; total observations = 4508; age = 0-5 years) between 2018 and 2020. Daasanach growth was compared to international reference standards and Daasanach-specific centile growth curves and pseudo-velocity models were generated using generalized additive models for location scale and size.<h4>Results</h4>Compared to World Health Organization (WHO) reference, relatively few Daasanach children were stunted (14.3%), while a large proportion were underweight (38.5%) and wasted (53.6%). Additionally, Daasanach children had a distinctive pattern of growth, marked by an increase in linear growth velocity after 24 months of age and relatively high linear growth velocity throughout the rest of early childhood.<h4>Conclusions</h4>These results identify a unique pattern of early childhood growth faltering among children in a small-scale population and may reflect a thermoregulatory adaptation to their hot, arid environment. As linear growth and weight gain remain important indicators of health, the results of this study provide insight into growth velocity variations. This study has important implications for global public health efforts to identify and address sources of early growth faltering and undernutrition in small-scale populations.}, Doi = {10.1002/ajhb.23842}, Key = {fds368054} } @article{fds374096, Author = {Speakman, JR and de Jong, JMA and Sinha, S and Westerterp, KR and Yamada, Y and Sagayama, H and Ainslie, PN and Anderson, LJ and Arab, L and Bedu-Addo, K and Blanc, S and Bonomi, AG and Bovet, P and Brage, S and Buchowski, MS and Butte, NF and Camps, SGJA and Cooper, JA and Cooper, R and Das, SK and Davies, PSW and Dugas, LR and Ekelund, U and Entringer, S and Forrester, T and Fudge, BW and Gillingham, M and Ghosh, S and Goris, AH and Gurven, M and Halsey, LG and Hambly, C and Haisma, HH and Hoffman, D and Hu, S and Joosen, AM and Kaplan, JL and Katzmarzyk, P and Kraus, WE and Kushner, RF and Leonard, WR and Löf, M and Martin, CK and Matsiko, E and Medin, AC and Meijer, EP and Neuhouser, ML and Nicklas, TA and Ojiambo, RM and Pietiläinen, KH and Plange-Rhule, J and Plasqui, G and Prentice, RL and Racette, SB and Raichlen, DA and Ravussin, E and Redman, LM and Roberts, SB and Rudolph, MC and Sardinha, LB and Schuit, AJ and Silva, AM and Stice, E and Urlacher, SS and Valenti, G and Van Etten and LM and Van Mil, EA and Wood, BM and Yanovski, JA and Yoshida, T and Zhang, X and Murphy-Alford, AJ and Loechl, CU and Kurpad, A and Luke, AH and Pontzer, H and Rodeheffer, MS and Rood, J and Schoeller, DA and Wong, WW}, Title = {Total daily energy expenditure has declined over the past three decades due to declining basal expenditure, not reduced activity expenditure.}, Journal = {Nat Metab}, Volume = {5}, Number = {4}, Pages = {579-588}, Year = {2023}, Month = {April}, url = {http://dx.doi.org/10.1038/s42255-023-00782-2}, Abstract = {Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor.}, Doi = {10.1038/s42255-023-00782-2}, Key = {fds374096} } @article{fds369976, Author = {McGrosky, A and Pontzer, H}, Title = {The fire of evolution: energy expenditure and ecology in primates and other endotherms.}, Journal = {The Journal of experimental biology}, Volume = {226}, Number = {5}, Pages = {jeb245272}, Year = {2023}, Month = {March}, url = {http://dx.doi.org/10.1242/jeb.245272}, Abstract = {Total energy expenditure (TEE) represents the total energy allocated to growth, reproduction and body maintenance, as well as the energy expended on physical activity. Early experimental work in animal energetics focused on the costs of specific tasks (basal metabolic rate, locomotion, reproduction), while determination of TEE was limited to estimates from activity budgets or measurements of subjects confined to metabolic chambers. Advances in recent decades have enabled measures of TEE in free-living animals, challenging traditional additive approaches to understanding animal energy budgets. Variation in lifestyle and activity level can impact individuals' TEE on short time scales, but interspecific differences in TEE are largely shaped by evolution. Here, we review work on energy expenditure across the animal kingdom, with a particular focus on endotherms, and examine recent advances in primate energetics. Relative to other placental mammals, primates have low TEE, which may drive their slow pace of life and be an evolved response to the challenges presented by their ecologies and environments. TEE variation among hominoid primates appears to reflect adaptive shifts in energy throughput and allocation in response to ecological pressures. As the taxonomic breadth and depth of TEE data expand, we will be able to test additional hypotheses about how energy budgets are shaped by environmental pressures and explore the more proximal mechanisms that drive intra-specific variation in energy expenditure.}, Doi = {10.1242/jeb.245272}, Key = {fds369976} } @article{fds368299, Author = {Pontzer, H}, Title = {Exercise is essential for health but a poor tool for weight loss: a reply to Allison and colleagues.}, Journal = {International journal of obesity (2005)}, Volume = {47}, Number = {2}, Pages = {98-99}, Year = {2023}, Month = {February}, url = {http://dx.doi.org/10.1038/s41366-022-01248-3}, Doi = {10.1038/s41366-022-01248-3}, Key = {fds368299} } @article{fds369846, Author = {Sadhir, S and Pontzer, H}, Title = {Impact of energy availability and physical activity on variation in fertility across human populations.}, Journal = {Journal of physiological anthropology}, Volume = {42}, Number = {1}, Pages = {1}, Year = {2023}, Month = {February}, url = {http://dx.doi.org/10.1186/s40101-023-00318-3}, Abstract = {Human reproduction is energetically costly, even more so than other primates. In this review, we consider how the energy cost of physical activity impacts reproductive tasks. Daily energy expenditure appears to be constrained, leading to trade-offs between activity and reproduction expenditures in physically active populations. High workloads can lead to suppression of basal metabolic rate and low gestational weight gain during pregnancy and longer interbirth intervals. These responses lead to variation in fertility, including age at first reproduction and interbirth interval. The influence of energetics is evident even in industrialized populations, where cultural and economic factors predominate. With the decoupling of skills acquisition from food procurement, extrasomatic resources and investment in individual offspring becomes very costly. The result is greater investment in fewer offspring. We present a summary of age at first reproduction and interbirth interval trends across a diverse, global sample representing 44 countries and two natural fertility populations. While economic factors impact fertility, women in energy-rich, industrialized populations are capable of greater reproductive output than women in energy-stressed populations. Thus, energetic factors can be disentangled from cultural and economic impacts on fertility. Future research should focus on objective measurements of energy intake, energy expenditure, and physical activity in a broader sample of populations to elucidate the role of energetics in shaping reproductive outcomes and health.}, Doi = {10.1186/s40101-023-00318-3}, Key = {fds369846} } @article{fds367802, Author = {Rimbach, R and Butler, G and Gupte, PR and Jäger, J and Parker, C and Pontzer, H}, Title = {Gray squirrels consume anthropogenic food waste most often during winter.}, Journal = {Mammalian biology = Zeitschrift fur Saugetierkunde}, Volume = {103}, Number = {1}, Pages = {69-81}, Year = {2023}, Month = {January}, url = {http://dx.doi.org/10.1007/s42991-022-00326-3}, Abstract = {Urban habitats provide wildlife with predictable, easily accessible and abundant food sources in the form of human food waste. Urban eastern gray squirrels (<i>Sciurus carolinensis</i>) are commonly observed feeding in trash bins, but we lack data regarding the type, quantity and seasonal changes in food waste usage. We observed five trash bins on an urban university campus during four different observation periods. We recorded the time squirrels spent on and inside trash bins and type of retrieved food items. We also recorded ambient temperature, human presence and trash bin filling. Moreover, we determined changes in squirrel population density in a natural and three anthropogenic habitats during the same periods. Trash bins were fuller when human presence was higher. The higher human presence, the more squirrels went on and inside the bin, but there was no effect on number of retrieved food items. Trash bin usage by squirrels decreased when ambient temperature and bin filling increased. Most food items were retrieved during the coldest observation period, a period of high human presence, and the majority of retrieved food items were starchy foods (e.g., bread, French fries). The relationship between the number of squirrels observed along transects and a measure of urbanization, the normalized difference built-up index, was negative in periods with high ambient temperatures and positive in periods with low ambient temperatures, indicating winter may be less challenging in urban areas, likely facilitated by the availability of anthropogenic food sources, allowing a higher level of activity throughout winter.<h4>Supplementary information</h4>The online version contains supplementary material available at 10.1007/s42991-022-00326-3.}, Doi = {10.1007/s42991-022-00326-3}, Key = {fds367802} } @article{fds367920, Author = {Ford, LB and Bethancourt, HJ and Swanson, ZS and Nzunza, R and Wutich, A and Brewis, A and Young, S and Almeida, DM and Douglass, M and Ndiema, EK and Braun, DR and Pontzer, H and Rosinger, AY}, Title = {Water insecurity, water borrowing and psychosocial stress among Daasanach pastoralists in northern Kenya}, Journal = {Water International}, Volume = {48}, Number = {1}, Pages = {63-86}, Year = {2023}, Month = {January}, url = {http://dx.doi.org/10.1080/02508060.2022.2138050}, Abstract = {This article quantifies Daasanach water insecurity experiences in northern Kenya, examines how water insecurity is associated with water borrowing and psychosocial stress, and evaluates if water borrowing mitigates the stress from water insecurity. Of 133 households interviewed in seven communities, 94.0% were water insecure and 74.4% borrowed water three or more times in the prior month. Regression analyses demonstrate water-borrowing frequency moderates the relationship between water insecurity and psychosocial stress. Only those who rarely or never borrowed water reported greater stress with higher water insecurity. The coping mechanism of water borrowing may help blunt water insecurity-related stress.}, Doi = {10.1080/02508060.2022.2138050}, Key = {fds367920} } @article{fds373952, Author = {Swanson, ZS and Bethancourt, H and Nzunza, R and Ndiema, E and Braun, DR and Rosinger, AY and Pontzer, H}, Title = {The effects of lifestyle change on indicators of cardiometabolic health in semi-nomadic pastoralists.}, Journal = {Evolution, medicine, and public health}, Volume = {11}, Number = {1}, Pages = {318-331}, Year = {2023}, Month = {January}, url = {http://dx.doi.org/10.1093/emph/eoad030}, Abstract = {<h4>Background and objectives</h4>Non-communicable disease risk and the epidemic of cardiometabolic diseases continue to grow across the expanding industrialized world. Probing the relationships between evolved human physiology and modern socioecological conditions is central to understanding this health crisis. Therefore, we investigated the relationships between increased market access, shifting subsistence patterns and cardiometabolic health indicators within Daasanach semi-nomadic pastoralists who vary in their engagement in traditional lifestyle and emerging market behaviors.<h4>Methodology</h4>We conducted cross-sectional socioecological, demographic and lifestyle stressor surveys along with health, biomarker and nutrition examinations among 225 (51.6% female) Daasanach adults in 2019-2020. We used linear mixed-effects models to test how differing levels of engagement in market integration and traditional subsistence activities related to blood pressure (BP), body composition and blood chemistry.<h4>Results</h4>We found that systolic and diastolic BP, as well as the probability of having high BP (hypertension), were negatively associated with distance to market, a proxy for market integration. Additionally, body composition varied significantly by socioeconomic status (SES), with significant positive associations between BMI and body fat and higher SES among adults.<h4>Conclusions and implications</h4>While evidence for evolutionary mismatch and health variation have been found across a number of populations affected by an urban/rural divide, these results demonstrate the effects of market integration and sedentarization on cardiometabolic health associated with the early stages of lifestyle changes. Our findings provide evidence for the changes in health when small-scale populations begin the processes of sedentarization and market integration that result from myriad market pressures.}, Doi = {10.1093/emph/eoad030}, Key = {fds373952} } @article{fds374951, Author = {Parker, CH and Sadhir, S and Swanson, Z and McGrosky, A and Hinz, E and Urlacher, SS and Pontzer, H}, Title = {Effect of influenza vaccination on resting metabolic rate and c-reactive protein concentrations in healthy young adults.}, Journal = {PloS one}, Volume = {18}, Number = {12}, Pages = {e0295540}, Year = {2023}, Month = {January}, url = {http://dx.doi.org/10.1371/journal.pone.0295540}, Abstract = {<h4>Objectives</h4>Chronic immune activation and severe inflammatory states are positively associated with resting metabolic rate (RMR; kcal/day), but the impacts of mild immune stimuli on metabolism are poorly understood. This study investigates the within-individual association between the inflammatory response to influenza vaccination and RMR in young adults.<h4>Methods</h4>We evaluated RMRs through indirect calorimetry and circulating c-reactive protein (CRP) concentrations (mg/L)-a direct measure of inflammation-via high-sensitivity immunoassays of dried blood spots (n = 17) at baseline and two- and seven-days post-vaccine. Wilcoxon matched-pairs signed-rank tests were used to evaluate the magnitude of the CRP and RMR responses. Type II Wald chi-square tests of linear mixed-effect models assessed whether those responses were correlated.<h4>Results</h4>Baseline CRP was 1.39 ± 1.26 mg/L. On day two post-vaccine, CRP increased by 1.47 ± 1.37 mg/L (p < 0.0001), representing a 106% increase above baseline values. CRP remained higher on day seven post-vaccine, 1.32 ± 2.47 mg/L (p = 0.05) above baseline values. There were no statistically significant changes in RMR from baseline to day two (p = 0.98) or day seven (p = 0.21). Change in CRP from baseline did not predict RMR variation across days (p = 0.46).<h4>Conclusions</h4>We find no evidence that adult influenza vaccination results in a corresponding increase in RMR. These results suggest that the energetic cost of an influenza vaccine's mild inflammatory stimulus is either too small to detect or is largely compensated by a temporary downregulation of energy allocated to other metabolic tasks.}, Doi = {10.1371/journal.pone.0295540}, Key = {fds374951} } @article{fds367867, Author = {Yamada, Y and Zhang, X and Henderson, MET and Sagayama, H and Pontzer, H and Watanabe, D and Yoshida, T and Kimura, M and Ainslie, PN and Andersen, LF and Anderson, LJ and Arab, L and Baddou, I and Bedu-Addo, K and Blaak, EE and Blanc, S and Bonomi, AG and Bouten, CVC and Bovet, P and Buchowski, MS and Butte, NF and Camps, SG and Close, GL and Cooper, JA and Cooper, R and Das, SK and Dugas, LR and Eaton, S and Ekelund, U and Entringer, S and Forrester, T and Fudge, BW and Goris, AH and Gurven, M and Halsey, LG and Hambly, C and El Hamdouchi and A and Hoos, MB and Hu, S and Joonas, N and Joosen, AM and Katzmarzyk, P and Kempen, KP and Kraus, WE and Kriengsinyos, W and Kushner, RF and Lambert, EV and Leonard, WR and Lessan, N and Martin, CK and Medin, AC and Meijer, EP and Morehen, JC and Morton, JP and Neuhouser, ML and Nicklas, TA and Ojiambo, RM and Pietiläinen, KH and Pitsiladis, YP and Plange-Rhule, J and Plasqui, G and Prentice, RL and Rabinovich, RA and Racette, SB and Raichlen, DA and Ravussin, E and Redman, LM and Reilly, JJ and Reynolds, RM and Roberts, SB and Schuit, AJ and Sardinha, LB and Silva, AM and Sjödin, AM and Stice, E and Urlacher, SS and Valenti, G and Van Etten and LM and Van Mil and EA and Wells, JCK and Wilson, G and Wood, BM and Yanovski, JA and Murphy-Alford, AJ and Loechl, CU and Luke, AH and Rood, J and Westerterp, KR and Wong, WW and Miyachi, M and Schoeller, DA and Speakman, JR and International Atomic Energy Agency (IAEA) Doubly Labeled Water (DLW) Database Consortium§}, Title = {Variation in human water turnover associated with environmental and lifestyle factors.}, Journal = {Science}, Volume = {378}, Number = {6622}, Pages = {909-915}, Year = {2022}, Month = {November}, url = {http://dx.doi.org/10.1126/science.abm8668}, Abstract = {Water is essential for survival, but one in three individuals worldwide (2.2 billion people) lacks access to safe drinking water. Water intake requirements largely reflect water turnover (WT), the water used by the body each day. We investigated the determinants of human WT in 5604 people from the ages of 8 days to 96 years from 23 countries using isotope-tracking (2H) methods. Age, body size, and composition were significantly associated with WT, as were physical activity, athletic status, pregnancy, socioeconomic status, and environmental characteristics (latitude, altitude, air temperature, and humidity). People who lived in countries with a low human development index (HDI) had higher WT than people in high-HDI countries. On the basis of this extensive dataset, we provide equations to predict human WT in relation to anthropometric, economic, and environmental factors.}, Doi = {10.1126/science.abm8668}, Key = {fds367867} } @article{fds367252, Author = {Hora, M and Pontzer, H and Struška, M and Entin, P and Sládek, V}, Title = {Comparing walking and running in persistence hunting.}, Journal = {Journal of human evolution}, Volume = {172}, Pages = {103247}, Year = {2022}, Month = {November}, url = {http://dx.doi.org/10.1016/j.jhevol.2022.103247}, Abstract = {It has been proposed that humans' exceptional locomotor endurance evolved partly with foraging in hot open habitats and subsequently about 2 million years ago with persistence hunting, for which endurance running was instrumental. However, persistence hunting by walking, if successful, could select for locomotor endurance even before the emergence of any running-related traits in human evolution. Using a heat exchange model validated here in 73 humans and 55 ungulates, we simulated persistence hunts for prey of three sizes (100, 250, and 400 kg) and three sweating capacities (nonsweating, low, high) at 6237 combinations of hunter's velocity (1-5 m s<sup>-1</sup>, intermittent), air temperature (25-45 °C), relative humidity (30-90%), and start time (8:00-16:00). Our simulations predicted that walking would be successful in persistence hunting of low- and nonsweating prey, especially under hot and humid conditions. However, simulated persistence hunts by walking yielded a 30-74% lower success rate than hunts by running or intermittent running. In addition, despite requiring 10-30% less energy, successful simulated persistence hunts by walking were twice as long and resulted in greater exhaustion of the hunter than hunts by running and intermittent running. These shortcomings of pursuit by walking compared to running identified in our simulations could explain why there is only a single direct description of persistence hunting by walking among modern hunter-gatherers. Nevertheless, walking down prey could be a viable option for hominins who did not possess the endurance-running phenotype of the proposed first persistence hunter, Homo erectus. Our simulation results suggest that persistence hunting could select for both long-distance walking and endurance running and contribute to the evolution of locomotor endurance seen in modern humans.}, Doi = {10.1016/j.jhevol.2022.103247}, Key = {fds367252} } @article{fds366134, Author = {Halsey, LG and Careau, V and Pontzer, H and Ainslie, PN and Andersen, LF and Anderson, LJ and Arab, L and Baddou, I and Bedu-Addo, K and Blaak, EE and Blanc, S and Bonomi, AG and Bouten, CVC and Bovet, P and Buchowski, MS and Butte, NF and Camps, SGJA and Close, GL and Cooper, JA and Das, SK and Cooper, R and Dugas, LR and Ekelund, U and Entringer, S and Forrester, T and Fudge, BW and Goris, AH and Gurven, M and Hambly, C and Hamdouchi, AE and Hoos, MB and Hu, S and Joonas, N and Joosen, AM and Katzmarzyk, P and Kempen, KP and Kimura, M and Kraus, WE and Kushner, RF and Lambert, EV and Leonard, WR and Lessan, N and Martin, CK and Medin, AC and Meijer, EP and Morehen, JC and Morton, JP and Neuhouser, ML and Nicklas, TA and Ojiambo, RM and Pietiläinen, KH and Pitsiladis, YP and Plange-Rhule, J and Plasqui, G and Prentice, RL and Rabinovich, RA and Racette, SB and Raichlen, DA and Ravussin, E and Reynolds, RM and Roberts, SB and Schuit, AJ and Sjödin, AM and Stice, E and Urlacher, SS and Valenti, G and Van Etten and LM and Van Mil and EA and Wilson, G and Wood, BM and Yanovski, J and Yoshida, T and Zhang, X and Murphy-Alford, AJ and Loechl, CU and Luke, AH and Rood, J and Sagayama, H and Schoeller, DA and Westerterp, KR and Wong, WW and Yamada, Y and Speakman, JR}, Title = {Variability in energy expenditure is much greater in males than females.}, Journal = {J Hum Evol}, Volume = {171}, Pages = {103229}, Year = {2022}, Month = {October}, url = {http://dx.doi.org/10.1016/j.jhevol.2022.103229}, Abstract = {In mammals, trait variation is often reported to be greater among males than females. However, to date, mainly only morphological traits have been studied. Energy expenditure represents the metabolic costs of multiple physical, physiological, and behavioral traits. Energy expenditure could exhibit particularly high greater male variation through a cumulative effect if those traits mostly exhibit greater male variation, or a lack of greater male variation if many of them do not. Sex differences in energy expenditure variation have been little explored. We analyzed a large database on energy expenditure in adult humans (1494 males and 3108 females) to investigate whether humans have evolved sex differences in the degree of interindividual variation in energy expenditure. We found that, even when statistically comparing males and females of the same age, height, and body composition, there is much more variation in total, activity, and basal energy expenditure among males. However, with aging, variation in total energy expenditure decreases, and because this happens more rapidly in males, the magnitude of greater male variation, though still large, is attenuated in older age groups. Considerably greater male variation in both total and activity energy expenditure could be explained by greater male variation in levels of daily activity. The considerably greater male variation in basal energy expenditure is remarkable and may be explained, at least in part, by greater male variation in the size of energy-demanding organs. If energy expenditure is a trait that is of indirect interest to females when choosing a sexual partner, this would suggest that energy expenditure is under sexual selection. However, we present a novel energetics model demonstrating that it is also possible that females have been under stabilizing selection pressure for an intermediate basal energy expenditure to maximize energy available for reproduction.}, Doi = {10.1016/j.jhevol.2022.103229}, Key = {fds366134} } @article{fds364203, Author = {Zhang, X and Yamada, Y and Sagayama, H and Ainslie, PN and Blaak, EE and Buchowski, MS and Close, GL and Cooper, JA and Das, SK and Dugas, LR and Gurven, M and El Hamdouchi and A and Hu, S and Joonas, N and Katzmarzyk, P and Kraus, WE and Kushner, RF and Leonard, WR and Martin, CK and Meijer, EP and Neuhouser, ML and Ojiambo, RM and Pitsiladis, YP and Plasqui, G and Prentice, RL and Racette, SB and Ravussin, E and Redman, LM and Reynolds, RM and Roberts, SB and Sardinha, LB and Silva, AM and Stice, E and Urlacher, SS and Van Mil and EA and Wood, BM and Murphy-Alford, AJ and Loechl, C and Luke, AH and Rood, J and Schoeller, DA and Westerterp, KR and Wong, WW and Pontzer, H and Speakman, JR and IAEA DLW database consortium}, Title = {Human total, basal and activity energy expenditures are independent of ambient environmental temperature.}, Journal = {iScience}, Volume = {25}, Number = {8}, Pages = {104682}, Year = {2022}, Month = {August}, url = {http://dx.doi.org/10.1016/j.isci.2022.104682}, Abstract = {Lower ambient temperature (Ta) requires greater energy expenditure to sustain body temperature. However, effects of Ta on human energetics may be buffered by environmental modification and behavioral compensation. We used the IAEA DLW database for adults in the USA (n = 3213) to determine the effect of Ta (-10 to +30°C) on TEE, basal (BEE) and activity energy expenditure (AEE) and physical activity level (PAL). There were no significant relationships (p > 0.05) between maximum, minimum and average Ta and TEE, BEE, AEE and PAL. After adjustment for fat-free mass, fat mass and age, statistically significant (p < 0.01) relationships between TEE, BEE and Ta emerged in females but the effect sizes were not biologically meaningful. Temperatures inside buildings are regulated at 18-25°C independent of latitude. Hence, adults in the US modify their environments to keep TEE constant across a wide range of external ambient temperatures.}, Doi = {10.1016/j.isci.2022.104682}, Key = {fds364203} } @article{fds365839, Author = {Bethancourt, HJ and Swanson, ZS and Nzunza, R and Young, SL and Lomeiku, L and Douglass, MJ and Braun, DR and Ndiema, EK and Pontzer, H and Rosinger, AY}, Title = {The co-occurrence of water insecurity and food insecurity among Daasanach pastoralists in northern Kenya.}, Journal = {Public health nutrition}, Pages = {1-11}, Year = {2022}, Month = {August}, url = {http://dx.doi.org/10.1017/s1368980022001689}, Abstract = {<h4>Objective</h4>Water plays a critical role in the production of food and preparation of nutritious meals, yet few studies have examined the relationship between water and food insecurity. The primary objective of this study, therefore, was to examine how experiences of household water insecurity (HWI) relate to experiences of household food insecurity (HFI) among a pastoralist population living in an arid, water-stressed region of northern Kenya.<h4>Design</h4>We implemented the twelve-item Household Water Insecurity Experiences (HWISE, range 0-36) Scale and the nine-item Household Food Insecurity Access Scale (HFIAS, range 0-27) in a cross-sectional survey to measure HWI and HFI, respectively. Data on socio-demographic characteristics and intake of meat and dairy in the prior week were collected as covariates of interest.<h4>Setting</h4>Northern Kenya, June-July 2019.<h4>Participants</h4>Daasanach pastoralist households (<i>n</i> 136) from seven communities.<h4>Results</h4>In the prior 4 weeks, 93·4 % and 98·5 % of households had experienced moderate-to-severe HWI and HFI, respectively. Multiple linear regression analyses indicated a strong association between HWI and HFI. Each point higher HWISE score was associated with a 0·44-point (95 % CI: 0·22, 0·66, <i>P</i> = 0·003) higher HFIAS score adjusting for socio-economic status and other covariates.<h4>Conclusions</h4>These findings demonstrate high prevalence and co-occurrence of HWI and HFI among Daasanach pastoralists in northern Kenya. This study highlights the need to address HWI and HFI simultaneously when developing policies and interventions to improve the nutritional well-being of populations whose subsistence is closely tied to water availability and access.}, Doi = {10.1017/s1368980022001689}, Key = {fds365839} } @article{fds361188, Author = {Rosinger, AY and Bethancourt, HJ and Swanson, ZS and Lopez, K and Kenney, WL and Huanca, T and Conde, E and Nzunza, R and Ndiema, E and Braun, DR and Pontzer, H}, Title = {Cross-cultural variation in thirst perception in hot-humid and hot-arid environments: Evidence from two small-scale populations.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {34}, Number = {6}, Pages = {e23715}, Year = {2022}, Month = {June}, url = {http://dx.doi.org/10.1002/ajhb.23715}, Abstract = {<h4>Objectives</h4>Thirst is an evolved central homeostatic feedback system that helps regulate body water for survival. Little research has examined how early development and exposure to extreme environments and water availability affect thirst perception, particularly outside Western settings. Therefore, we compared two indicators of perceived thirst (current thirst and pleasantness of drinking water) using visual scales among Tsimane' forager-horticulturalists in the hot-humid Bolivian Amazon and Daasanach agro-pastoralists in hot-arid Northern Kenya.<h4>Methods</h4>We examined how these measures of perceived thirst were associated with hydration status (urine specific gravity), ambient temperatures, birth season, age, and population-specific characteristics for 607 adults (n = 378 Tsimane', n = 229 Daasanach) aged 18+ using multi-level mixed-effect regressions.<h4>Results</h4>Tsimane' had higher perceived thirst than Daasanach. Across populations, hydration status was unrelated to both measures of thirst. There was a significant interaction between birth season and temperature on pleasantness of drinking water, driven by Kenya data. Daasanach born in the wet season (in utero during less water availability) had blunted pleasantness of drinking water at higher temperatures compared to those born in the dry season (in utero during greater water availability).<h4>Conclusions</h4>Our findings suggest hydration status is not a reliable predictor of thirst perceptions in extreme-hot environments with ad libitum drinking. Rather, our findings, which require additional confirmation, point to the importance of water availability during gestation in affecting thirst sensitivity to heat and water feedback mechanisms, particularly in arid environments. Thirst regulation will be increasingly important to understand given climate change driven exposures to extreme heat and water insecurity.}, Doi = {10.1002/ajhb.23715}, Key = {fds361188} } @article{fds363883, Author = {Pontzer, H and McGrosky, A}, Title = {Balancing growth, reproduction, maintenance, and activity in evolved energy economies.}, Journal = {Current biology : CB}, Volume = {32}, Number = {12}, Pages = {R709-R719}, Year = {2022}, Month = {June}, url = {http://dx.doi.org/10.1016/j.cub.2022.05.018}, Abstract = {Economic models predominate in life history research, which investigates the allocation of an organism's resources to growth, reproduction, and maintenance. These approaches typically employ a heuristic Y model of resource allocation, which predicts trade-offs among tasks within a fixed budget. The common currency among tasks is not always specified, but most models imply that metabolic energy, either from food or body stores, is the critical resource. Here, we review the evidence for metabolic energy as the common currency of growth, reproduction, and maintenance, focusing on studies in humans and other vertebrates. We then discuss the flow of energy to competing physiological tasks (physical activity, maintenance, and reproduction or growth) and its effect on life history traits. We propose a Ψ model of energy flow to these tasks, which provides an integrative framework for examining the influence of environmental factors and the expansion and contraction of energy budgets in the evolution of life history strategies.}, Doi = {10.1016/j.cub.2022.05.018}, Key = {fds363883} } @article{fds361302, Author = {Rimbach, R and Yamada, Y and Sagayama, H and Ainslie, PN and Anderson, LF and Anderson, LJ and Arab, L and Baddou, I and Bedu-Addo, K and Blaak, EE and Blanc, S and Bonomi, AG and Bouten, CVC and Bovet, P and Buchowski, MS and Butte, NF and Camps, SGJA and Close, GL and Cooper, JA and Das, SK and Dugas, LR and Ekelund, U and Entringer, S and Forrester, T and Fudge, BW and Goris, AH and Gurven, M and Hambly, C and El Hamdouchi and A and Hoos, MB and Hu, S and Joonas, N and Joosen, AM and Katzmarzyk, P and Kempen, KP and Kimura, M and Kraus, WE and Kushner, RF and Lambert, EV and Leonard, WR and Lessan, N and Martin, CK and Medin, AC and Meijer, EP and Morehen, JC and Morton, JP and Neuhouser, ML and Nicklas, TA and Ojiambo, RM and Pietiläinen, KH and Pitsiladis, YP and Plange-Rhule, J and Plasqui, G and Prentice, RL and Rabinovich, RA and Racette, SB and Raichlen, DA and Ravussin, E and Reynolds, RM and Roberts, SB and Schuit, AJ and Sjödin, AM and Stice, E and Urlacher, SS and Valenti, G and Van Etten and LM and Van Mil, EA and Wells, JCK and Wilson, G and Wood, BM and Yanovski, J and Yoshida, T and Zhang, X and Murphy-Alford, AJ and Loechl, CU and Luke, AH and Rood, J and Schoeller, DA and Westerterp, KR and Wong, WW and Speakman, JR and Pontzer, H and IAEA DLW Database Consortium}, Title = {Total energy expenditure is repeatable in adults but not associated with short-term changes in body composition.}, Journal = {Nat Commun}, Volume = {13}, Number = {1}, Pages = {99}, Year = {2022}, Month = {January}, url = {http://dx.doi.org/10.1038/s41467-021-27246-z}, Abstract = {Low total energy expenditure (TEE, MJ/d) has been a hypothesized risk factor for weight gain, but repeatability of TEE, a critical variable in longitudinal studies of energy balance, is understudied. We examine repeated doubly labeled water (DLW) measurements of TEE in 348 adults and 47 children from the IAEA DLW Database (mean ± SD time interval: 1.9 ± 2.9 y) to assess repeatability of TEE, and to examine if TEE adjusted for age, sex, fat-free mass, and fat mass is associated with changes in weight or body composition. Here, we report that repeatability of TEE is high for adults, but not children. Bivariate Bayesian mixed models show no among or within-individual correlation between body composition (fat mass or percentage) and unadjusted TEE in adults. For adults aged 20-60 y (N = 267; time interval: 7.4 ± 12.2 weeks), increases in adjusted TEE are associated with weight gain but not with changes in body composition; results are similar for subjects with intervals >4 weeks (N = 53; 29.1 ± 12.8 weeks). This suggests low TEE is not a risk factor for, and high TEE is not protective against, weight or body fat gain over the time intervals tested.}, Doi = {10.1038/s41467-021-27246-z}, Key = {fds361302} } @article{fds361799, Author = {Willis, EA and Creasy, SA and Saint-Maurice, PF and Keadle, SK and Pontzer, H and Schoeller, D and Troiano, RP and Matthews, CE}, Title = {Physical Activity and Total Daily Energy Expenditure in Older US Adults: Constrained versus Additive Models.}, Journal = {Medicine and science in sports and exercise}, Volume = {54}, Number = {1}, Pages = {98-105}, Year = {2022}, Month = {January}, url = {http://dx.doi.org/10.1249/mss.0000000000002759}, Abstract = {<h4>Purpose</h4>This study aimed to examine the shape of the relationship between physical activity (PA) and total energy expenditure (TEE) and to explore the role of energy balance status (negative, stable, positive) in influencing this association.<h4>Methods</h4>Cross-sectional. Participants were 584 older adults (50-74 yr) participating in the Interactive Diet and Activity Tracking in AARP study. TEE was assessed by doubly labeled water and PA by accelerometer. The relationship between PA and TEE was assessed visually and using nonlinear methods (restricted cubic splines). Percent weight change (>3%) over a 6-month period was used as a proxy measurement of energy balance status.<h4>Results</h4>TEE generally increased with increasing deciles of PA averaging 2354 (SD, 351) kcal·d-1 in the bottom decile to 2693 (SD, 480) kcal·d-1 in the top decile. Cubic spline models showed an approximate linear association between PA and TEE (linear relation, P < 0.0001; curvature, P = 0.920). Results were similar in subgroup analyses for individuals classified as stable or positive energy balance. For those in negative energy balance, TEE was generally flat with increasing deciles of PA averaging 2428 (SD, 285) kcal·d-1 in the bottom decile to 2372 (SD, 560) kcal·d-1 in the top decile.<h4>Conclusions</h4>Energy balance status seems to play an important role in the relationship between PA and TEE. When in a positive energy balance, the relationship between TEE and PA was consistent with an additive model; however, when energy balance was negative, TEE seems to be consistent with a constrained model. These findings support PA for weight gain prevention by increasing TEE; however, the effect of PA on TEE during periods of weight loss may be limited. An adequately powered, prospective study is warranted to confirm these exploratory findings.}, Doi = {10.1249/mss.0000000000002759}, Key = {fds361799} } @article{fds364045, Author = {Dunham, NT and Koester, DC and Dierenfeld, ES and Rimbach, R and Pontzer, H}, Title = {Balancing the scales: Preliminary investigation of total energy expenditure and daily metabolizable energy intake in Matschie's tree kangaroo (Dendrolagus matschiei).}, Journal = {PloS one}, Volume = {17}, Number = {6}, Pages = {e0270570}, Year = {2022}, Month = {January}, url = {http://dx.doi.org/10.1371/journal.pone.0270570}, Abstract = {Matschie's tree kangaroo (Dendrolagus matschiei) is an endangered arboreal marsupial native to Papua New Guinea. Detailed field studies of its behavior and ecology are scarce due largely to its occupation of remote cloud forests and cryptic nature. Although this species has been in human care since the 1950s, much of its biology is still unknown. The current ex situ population is not sustainable due to health and reproductive problems, believed to stem largely from issues with diet and obesity. To better assess potential discrepancies between energy requirements and energy intake, we sought to 1) quantify total energy expenditure (TEE) of two zoo-housed Matschie's tree kangaroos (body mass = 9.0-9.7 kg) on a diet composed largely of leafy browse; 2) quantify food and macronutrient intake, apparent dry matter macronutrient digestibility, and metabolizable energy (ME) intake over a 14-month period; and 3) test for seasonal changes in ME intake due to seasonal differences in the varieties of leafy browse offered. Using the doubly labeled water method, we determined TEE for the female (288 kcal day -1) and male (411 kcal day -1). Resulting mean TEE was well below the expected value for marsupials and macropods (i.e., ~60% of the expected value based on body mass). The mean calculated ME intakes for the female and male were 307 kcal day-1 and 454 kcal day-1, respectively. There were significant seasonal differences in ME intakes, driven by reduced intake in the autumn. These results demonstrate that Matschie's tree kangaroos can be maintained at healthy body weights and conditions on fiber-rich and browse-heavy diets. Our findings contribute important insights into tree kangaroo energetics and physiology and can be applied to help reformulate the diet of Matschie's tree kangaroos at captive facilities to improve population health and sustainability.}, Doi = {10.1371/journal.pone.0270570}, Key = {fds364045} } @article{fds364274, Author = {Klasson, CL and Sadhir, S and Pontzer, H}, Title = {Daily physical activity is negatively associated with thyroid hormone levels, inflammation, and immune system markers among men and women in the NHANES dataset.}, Journal = {PloS one}, Volume = {17}, Number = {7}, Pages = {e0270221}, Year = {2022}, Month = {January}, url = {http://dx.doi.org/10.1371/journal.pone.0270221}, Abstract = {The acute effects of exercise on metabolic energy expenditure and inflammation are well studied, but the long-term effects of regular daily physical activity on metabolic and endocrine effects are less clear. Further, prior studies investigating the impact of daily physical activity in large cohorts have generally relied on self-reported activity. Here, we used the U.S. National Health and Nutrition Examination Survey (NHANES) to investigate the relationship between daily physical activity and both thyroid and immune activity. Daily physical activity was assessed through accelerometry or accelerometry-validated survey responses. Thyroid activity was assessed from circulating levels of thyroid stimulating hormone (TSH) and thyroxine (T4). Immune function was assessed from circulating cytokines (C-reactive protein [CRP], immunoglobulin E [IgE], fibrinogen) and blood cell counts. In general linear models including body mass index, age, gender, activity and TSH as factors, active adults had a lower levels of T4 and reduced slope of the TSH:T4 relationship. Similarly, greater physical activity was associated with lower CRP and fibrinogen levels (but not IgE) and lower white blood cell, basophil, monocyte, neutrophil, and eosinophil (but not lymphocyte) counts. Daily physical activity was also associated with lower prevalence of clinically elevated CRP, WBC, and lymphocytes in a dose-response manner. These results underscore the long-term impact of daily physical activity on both systemic metabolic activity (thyroid) and on specific physiological tasks (immune). The regulatory effects of physical activity on other bodily systems are clinically relevant and should be incorporated into public health strategies promoting exercise.}, Doi = {10.1371/journal.pone.0270221}, Key = {fds364274} } @article{fds365596, Author = {Higgins, S and Pomeroy, A and Bates, LC and Paterson, C and Barone Gibbs, B and Pontzer, H and Stoner, L}, Title = {Sedentary behavior and cardiovascular disease risk: An evolutionary perspective.}, Journal = {Frontiers in physiology}, Volume = {13}, Pages = {962791}, Year = {2022}, Month = {January}, url = {http://dx.doi.org/10.3389/fphys.2022.962791}, Abstract = {A ubiquitous aspect of contemporary societies is sedentary behavior (SB), defined as low intensity activities in a seated, reclined, or supine posture. Leading public health agencies, including the World Health Organization, have recognized the strong association between SB and poor health outcomes, particularly cardiovascular disease. However, while public health agencies have begun to advocate for "reductions" in SB, the current US guidelines are typically vague and non-specific. There is good reasoning behind this non-committal advocacy-there is limited mechanistic and clinical evidence to support policy development. To guide SB policy development, it is important to first consider the origins and evolution of SB, including the following: 1) is SB really a novel/contemporary behavior? i.e., how has this behavior evolved? 2) how did our ancestors sit and in what contexts? 3) how does SB interact with 24-hour activity behaviors, including physical activity and sleep? 4) what other historical and contemporary facets of life interact with SB? and 5) in what context do these behaviors occur and how might they provide different evolutionarily novel stressors? This perspective article will synthesize the available evidence that addresses these questions and stimulate discussion pertaining to the lessons that we can learn from an historical and evolutionary perspective. Last, it will outline the gaps in current SB interruption literature that are hindering development of feasible SB reduction policy.}, Doi = {10.3389/fphys.2022.962791}, Key = {fds365596} } @article{fds361187, Author = {Kraft, TS and Venkataraman, VV and Wallace, IJ and Crittenden, AN and Holowka, NB and Stieglitz, J and Harris, J and Raichlen, DA and Wood, B and Gurven, M and Pontzer, H}, Title = {The energetics of uniquely human subsistence strategies.}, Journal = {Science (New York, N.Y.)}, Volume = {374}, Number = {6575}, Pages = {eabf0130}, Year = {2021}, Month = {December}, url = {http://dx.doi.org/10.1126/science.abf0130}, Abstract = {The suite of derived human traits, including enlarged brains, elevated fertility rates, and long developmental periods and life spans, imposes extraordinarily high energetic costs relative to other great apes. How do human subsistence strategies accommodate our expanded energy budgets? We found that relative to other great apes, human hunter-gatherers and subsistence farmers spend more energy but less time on subsistence, acquire substantially more energy per hour, and achieve similar energy efficiencies. These findings revise our understanding of human energetic evolution by indicating that humans afford expanded energy budgets primarily by increasing rates of energy acquisition, not through energy-saving adaptations such as economical bipedalism or sophisticated tool use that decrease subsistence costs and improve the energetic efficiency of subsistence. We argue that the time saved by human subsistence strategies provides more leisure time for social interaction and social learning in central-place locations and would have been critical for cumulative cultural evolution.}, Doi = {10.1126/science.abf0130}, Key = {fds361187} } @article{fds361189, Author = {Westerterp, KR and Yamada, Y and Sagayama, H and Ainslie, PN and Andersen, LF and Anderson, LJ and Arab, L and Baddou, I and Bedu-Addo, K and Blaak, EE and Blanc, S and Bonomi, AG and Bouten, CVC and Bovet, P and Buchowski, MS and Butte, NF and Camps, SGJA and Close, GL and Cooper, JA and Das, SK and Cooper, R and Dugas, LR and Ekelund, U and Entringer, S and Forrester, T and Fudge, BW and Goris, AH and Gurven, M and Hambly, C and El Hamdouchi, A and Hoos, MB and Hu, S and Joonas, N and Joosen, AM and Katzmarzyk, P and Kempen, KP and Kimura, M and Kraus, WE and Kushner, RF and Lambert, EV and Leonard, WR and Lessan, N and Martin, CK and Medin, AC and Meijer, EP and Morehen, JC and Morton, JP and Neuhouser, ML and Nicklas, TA and Ojiambo, RM and Pietiläinen, KH and Pitsiladis, YP and Plange-Rhule, J and Plasqui, G and Prentice, RL and Rabinovich, RA and Racette, SB and Raichlen, DA and Ravussin, E and Reynolds, RM and Roberts, SB and Schuit, AJ and Sjödin, AM and Stice, E and Urlacher, SS and Valenti, G and Van Etten and LM and Van Mil and EA and Wells, JCK and Wilson, G and Wood, BM and Yanovski, J and Yoshida, T and Zhang, X and Murphy-Alford, AJ and Loechl, CU and Luke, AH and Pontzer, H and Rood, J and Schoeller, DA and Wong, WW and Speakman, JR and International Atomic Energy Agency Doubly Labeled Water database group}, Title = {Physical activity and fat-free mass during growth and in later life.}, Journal = {Am J Clin Nutr}, Volume = {114}, Number = {5}, Pages = {1583-1589}, Year = {2021}, Month = {November}, url = {http://dx.doi.org/10.1093/ajcn/nqab260}, Abstract = {BACKGROUND: Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass. OBJECTIVES: A study is presented of the association between FFM and physical activity in relation to age. METHODS: In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3-96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution. RESULTS: PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males < 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants < 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM-adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: -0.2, 1.7 kg) and 1.0 kg (95% CI: -0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively. CONCLUSIONS: If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults.}, Doi = {10.1093/ajcn/nqab260}, Key = {fds361189} } @article{fds358810, Author = {Careau, V and Halsey, LG and Pontzer, H and Ainslie, PN and Andersen, LF and Anderson, LJ and Arab, L and Baddou, I and Bedu-Addo, K and Blaak, EE and Blanc, S and Bonomi, AG and Bouten, CVC and Buchowski, MS and Butte, NF and Camps, SGJA and Close, GL and Cooper, JA and Das, SK and Cooper, R and Dugas, LR and Eaton, SD and Ekelund, U and Entringer, S and Forrester, T and Fudge, BW and Goris, AH and Gurven, M and Hambly, C and El Hamdouchi, A and Hoos, MB and Hu, S and Joonas, N and Joosen, AM and Katzmarzyk, P and Kempen, KP and Kimura, M and Kraus, WE and Kushner, RF and Lambert, EV and Leonard, WR and Lessan, N and Martin, CK and Medin, AC and Meijer, EP and Morehen, JC and Morton, JP and Neuhouser, ML and Nicklas, TA and Ojiambo, RM and Pietiläinen, KH and Pitsiladis, YP and Plange-Rhule, J and Plasqui, G and Prentice, RL and Rabinovich, RA and Racette, SB and Raichlen, DA and Ravussin, E and Reilly, JJ and Reynolds, RM and Roberts, SB and Schuit, AJ and Sjödin, AM and Stice, E and Urlacher, SS and Valenti, G and Van Etten and LM and Van Mil and EA and Wells, JCK and Wilson, G and Wood, BM and Yanovski, J and Yoshida, T and Zhang, X and Murphy-Alford, AJ and Loechl, CU and Luke, AH and Rood, J and Sagayama, H and Schoeller, DA and Wong, WW and Yamada, Y and Speakman, JR and IAEA DLW database group}, Title = {Energy compensation and adiposity in humans.}, Journal = {Curr Biol}, Volume = {31}, Number = {20}, Pages = {4659-4666.e2}, Year = {2021}, Month = {October}, url = {http://dx.doi.org/10.1016/j.cub.2021.08.016}, Abstract = {Understanding the impacts of activity on energy balance is crucial. Increasing levels of activity may bring diminishing returns in energy expenditure because of compensatory responses in non-activity energy expenditures.1-3 This suggestion has profound implications for both the evolution of metabolism and human health. It implies that a long-term increase in activity does not directly translate into an increase in total energy expenditure (TEE) because other components of TEE may decrease in response-energy compensation. We used the largest dataset compiled on adult TEE and basal energy expenditure (BEE) (n = 1,754) of people living normal lives to find that energy compensation by a typical human averages 28% due to reduced BEE; this suggests that only 72% of the extra calories we burn from additional activity translates into extra calories burned that day. Moreover, the degree of energy compensation varied considerably between people of different body compositions. This association between compensation and adiposity could be due to among-individual differences in compensation: people who compensate more may be more likely to accumulate body fat. Alternatively, the process might occur within individuals: as we get fatter, our body might compensate more strongly for the calories burned during activity, making losing fat progressively more difficult. Determining the causality of the relationship between energy compensation and adiposity will be key to improving public health strategies regarding obesity.}, Doi = {10.1016/j.cub.2021.08.016}, Key = {fds358810} } @article{fds357317, Author = {Pontzer, H and Wood, BM}, Title = {Effects of Evolution, Ecology, and Economy on Human Diet: Insights from Hunter-Gatherers and Other Small-Scale Societies.}, Journal = {Annual review of nutrition}, Volume = {41}, Pages = {363-385}, Year = {2021}, Month = {October}, url = {http://dx.doi.org/10.1146/annurev-nutr-111120-105520}, Abstract = {We review the evolutionary origins of the human diet and the effects of ecology economy on the dietary proportion of plants and animals. Humans eat more meat than other apes, a consequence of hunting and gathering, which arose ∼2.5 Mya with the genus <i>Homo</i>. Paleolithic diets likely included a balance of plant and animal foods and would have been remarkably variable across time and space. A plant/animal food balance of 50/50% prevails among contemporary warm-climate hunter-gatherers, but these proportions vary widely. Societies in cold climates, and those that depend more on fishing or pastoralism, tend to eat more meat. Warm-climate foragers, and groups that engage in some farming, tend to eat more plants. We present a case study of the wild food diet of the Hadza, a community of hunter-gatherers in northern Tanzania, whose diet is high in fiber, adequate in protein, and remarkably variable over monthly timescales.}, Doi = {10.1146/annurev-nutr-111120-105520}, Key = {fds357317} } @article{fds358684, Author = {Pontzer, H and Yamada, Y and Sagayama, H and Ainslie, PN and Andersen, LF and Anderson, LJ and Arab, L and Baddou, I and Bedu-Addo, K and Blaak, EE and Blanc, S and Bonomi, AG and Bouten, CVC and Bovet, P and Buchowski, MS and Butte, NF and Camps, SG and Close, GL and Cooper, JA and Cooper, R and Das, SK and Dugas, LR and Ekelund, U and Entringer, S and Forrester, T and Fudge, BW and Goris, AH and Gurven, M and Hambly, C and El Hamdouchi and A and Hoos, MB and Hu, S and Joonas, N and Joosen, AM and Katzmarzyk, P and Kempen, KP and Kimura, M and Kraus, WE and Kushner, RF and Lambert, EV and Leonard, WR and Lessan, N and Martin, C and Medin, AC and Meijer, EP and Morehen, JC and Morton, JP and Neuhouser, ML and Nicklas, TA and Ojiambo, RM and Pietiläinen, KH and Pitsiladis, YP and Plange-Rhule, J and Plasqui, G and Prentice, RL and Rabinovich, RA and Racette, SB and Raichlen, DA and Ravussin, E and Reynolds, RM and Roberts, SB and Schuit, AJ and Sjödin, AM and Stice, E and Urlacher, SS and Valenti, G and Van Etten and LM and Van Mil and EA and Wells, JCK and Wilson, G and Wood, BM and Yanovski, J and Yoshida, T and Zhang, X and Murphy-Alford, AJ and Loechl, C and Luke, AH and Rood, J and Schoeller, DA and Westerterp, KR and Wong, WW and Speakman, JR and IAEA DLW Database Consortium}, Title = {Daily energy expenditure through the human life course.}, Journal = {Science}, Volume = {373}, Number = {6556}, Pages = {808-812}, Year = {2021}, Month = {August}, url = {http://dx.doi.org/10.1126/science.abe5017}, Abstract = {Total daily energy expenditure ("total expenditure") reflects daily energy needs and is a critical variable in human health and physiology, but its trajectory over the life course is poorly studied. We analyzed a large, diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 years. Total expenditure increased with fat-free mass in a power-law manner, with four distinct life stages. Fat-free mass-adjusted expenditure accelerates rapidly in neonates to ~50% above adult values at ~1 year; declines slowly to adult levels by ~20 years; remains stable in adulthood (20 to 60 years), even during pregnancy; then declines in older adults. These changes shed light on human development and aging and should help shape nutrition and health strategies across the life span.}, Doi = {10.1126/science.abe5017}, Key = {fds358684} } @article{fds358341, Author = {Rimbach, R and Amireh, A and Allen, A and Hare, B and Guarino, E and Kaufman, C and Salomons, H and Pontzer, H}, Title = {Total energy expenditure of bottlenose dolphins (Tursiops truncatus) of different ages.}, Journal = {The Journal of experimental biology}, Volume = {224}, Number = {15}, Pages = {jeb242218}, Year = {2021}, Month = {August}, url = {http://dx.doi.org/10.1242/jeb.242218}, Abstract = {Marine mammals are thought to have an energetically expensive lifestyle because endothermy is costly in marine environments. However, measurements of total energy expenditure (TEE; kcal day-1) are available only for a limited number of marine mammals, because large body size and inaccessible habitats make TEE measurements expensive and difficult to obtain for many taxa. We measured TEE in 10 adult common bottlenose dolphins (Tursiops truncatus) living in natural seawater lagoons at two facilities (Dolphin Research Center and Dolphin Quest) using the doubly labeled water method. We assessed the relative effects of body mass, age and physical activity on TEE. We also examined whether TEE of bottlenose dolphins, and more generally of marine mammals, differs from that expected for their body mass compared with other eutherian mammals, using phylogenetic least squares (PGLS) regressions. There were no differences in body mass or TEE (unadjusted TEE and TEE adjusted for fat-free mass) between dolphins from the two facilities. Our results show that adjusted TEE decreased and fat mass increased with age. Different measures of activity were not related to age, body fat or adjusted TEE. Both PGLS and the non-phylogenetic linear regression indicate that marine mammals have an elevated TEE compared with that of terrestrial mammals. However, bottlenose dolphins expended 17.1% less energy than other marine mammals of similar body mass. The two oldest dolphins (>40 years) showed a lower TEE, similar to the decline in TEE seen in older humans. To our knowledge, this is the first study to show an age-related metabolic decline in a large non-human mammal.}, Doi = {10.1242/jeb.242218}, Key = {fds358341} } @article{fds357552, Author = {Rimbach, R and Amireh, A and Allen, A and Hare, B and Guarino, E and Kaufman, C and Salomons, H and Pontzer, H}, Title = {Total energy expenditure of bottlenose dolphins (Tursiops truncatus) of different ages.}, Journal = {The Journal of experimental biology}, Year = {2021}, Month = {July}, url = {http://dx.doi.org/10.1242/jeb.242218}, Abstract = {Marine mammals are thought to have an energetically expensive lifestyle because endothermy is costly in marine environments. However, measurements of total energy expenditure (TEE; kcal/day) are available only for a limited number of marine mammals, because large body size and inaccessible habitats make TEE measurements expensive and difficult for many taxa. We measured TEE in 10 adult common bottlenose dolphins (Tursiops truncatus) living in natural seawater lagoons at two facilities (Dolphin Research Center and Dolphin Quest) using the doubly labeled water method. We assessed the relative effects of body mass, age, and physical activity on TEE. We also examined whether TEE of bottlenose dolphins, and more generally marine mammals, differs from that expected for their body mass compared to other eutherian mammals, using phylogenetic least squares (PGLS) regressions. There were no differences in body mass or TEE (unadjusted TEE and TEE adjusted for fat free mass (FFM)) between dolphins from both facilities. Our results show that Adjusted TEE decreased and fat mass (FM) increased with age. Different measures of activity were not related to age, body fat or Adjusted TEE. Both PGLS and the non-phylogenetic linear regression indicate that marine mammals have an elevated TEE compared to terrestrial mammals. However, bottlenose dolphins expended 17.1% less energy than other marine mammals of similar body mass. The two oldest dolphins (>40 years) showed a lower TEE, similar to the decline in TEE seen in older humans. To our knowledge, this is the first study to show an age-related metabolic decline in a large non-human mammal.}, Doi = {10.1242/jeb.242218}, Key = {fds357552} } @article{fds358685, Author = {Raichlen, DA and Pontzer, H}, Title = {Energetic and endurance constraints on great ape quadrupedalism and the benefits of hominin bipedalism.}, Journal = {Evolutionary anthropology}, Volume = {30}, Number = {4}, Pages = {253-261}, Year = {2021}, Month = {July}, url = {http://dx.doi.org/10.1002/evan.21911}, Abstract = {Bipedal walking was one of the first key behavioral traits that defined the evolution of early hominins. While it is not possible to identify specific selection pressures underlying bipedal evolution, we can better understand how the adoption of bipedalism may have benefited our hominin ancestors. Here, we focus on how bipedalism relaxes constraints on nonhuman primate quadrupedal limb mechanics, providing key advantages during hominin evolution. Nonhuman primate quadrupedal kinematics, especially in our closest living relatives, the great apes, are dominated by highly flexed limb joints, often associated with high energy costs, and are constrained by the need to reduce loads on mobile, but less stable forelimb joints. Bipedal walking would have allowed greater hind limb joint extension, which is associated with reduced energy costs and increased endurance. We suggest that relaxing these constraints provided bipedal hominins important benefits associated with long distance foraging and mobility.}, Doi = {10.1002/evan.21911}, Key = {fds358685} } @article{fds355698, Author = {Jones, JH and Pisor, AC and Douglass, KG and Bird, RB and Ready, E and Hazel, A and Hackman, J and Kramer, KL and Kohler, TA and Pontzer, H and Towner, MC}, Title = {How can evolutionary and biological anthropologists engage broader audiences?}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {33}, Number = {4}, Pages = {e23592}, Year = {2021}, Month = {July}, url = {http://dx.doi.org/10.1002/ajhb.23592}, Abstract = {<h4>Objectives</h4>With our diverse training, theoretical and empirical toolkits, and rich data, evolutionary and biological anthropologists (EBAs) have much to contribute to research and policy decisions about climate change and other pressing social issues. However, we remain largely absent from these critical, ongoing efforts. Here, we draw on the literature and our own experiences to make recommendations for how EBAs can engage broader audiences, including the communities with whom we collaborate, a more diverse population of students, researchers in other disciplines and the development sector, policymakers, and the general public. These recommendations include: (1) playing to our strength in longitudinal, place-based research, (2) collaborating more broadly, (3) engaging in greater public communication of science, (4) aligning our work with open-science practices to the extent possible, and (5) increasing diversity of our field and teams through intentional action, outreach, training, and mentorship.<h4>Conclusions</h4>We EBAs need to put ourselves out there: research and engagement are complementary, not opposed to each other. With the resources and workable examples we provide here, we hope to spur more EBAs to action.}, Doi = {10.1002/ajhb.23592}, Key = {fds355698} } @article{fds355707, Author = {Pontzer, H}, Title = {Hotter and sicker: External energy expenditure and the tangled evolutionary roots of anthropogenic climate change and chronic disease.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {33}, Number = {4}, Pages = {e23579}, Year = {2021}, Month = {July}, url = {http://dx.doi.org/10.1002/ajhb.23579}, Abstract = {<h4>Background</h4>The dual crises of climate change and chronic, or non-communicable, disease (NCD) have emerged worldwide as the global economy has industrialized over the past two centuries.<h4>Aims</h4>In this synthesis I examine humans' dependence on external (non-metabolic) energy expenditure (e.g., fire, fossil fuels) as a common, root cause in these modern crises.<h4>Materials and methods</h4>Using fossil, archeological, and historical evidence I show that the human lineage has been dependent on external energy sources since the control of fire in the Paleolithic. This reliance has grown with the development of agriculture, the use of wind- and water-power, and the most recently with industrialization and the transition to fossil fuels. To place industrialization in context I develop a Rule of 50, whereby individuals in industrialized economies consume roughly 50-times more external energy and manufacture roughly 50-times more material than do hunter-gatherers.<h4>Results</h4>Industrialization and mechanization, powered by fossil fuels, have promoted centralization and processing in food production, reduced physical activity, and increased air pollution (including greenhouse gas emissions). These developments have led in turn to NCD and climate change.<h4>Discussion and conclusion</h4>Climate change and NCD are connected both to one another and to our species' deep evolutionary dependence on external energy. Transitioning to carbon-free energy is essential to reduce the existential risks of climate change, but will likely have only modest effects on NCD. With the impending exhaustion of oil, coal, and natural gas reserves, developing replacements for fossil fuels is also critical to maintaining our species' external energy portfolio.}, Doi = {10.1002/ajhb.23579}, Key = {fds355707} } @article{fds357316, Author = {Kozma, EE and Pontzer, H}, Title = {Determinants of climbing energetic costs in humans.}, Journal = {The Journal of experimental biology}, Volume = {224}, Number = {13}, Pages = {jeb234567}, Year = {2021}, Month = {July}, url = {http://dx.doi.org/10.1242/jeb.234567}, Abstract = {Previous studies in primates and other animals have shown that mass-specific cost of transport (J kg-1 m-1) for climbing is independent of body size across species, but little is known about within-species allometry of climbing costs or the effects of difficulty and velocity. Here, we assessed the effects of velocity, route difficulty and anatomical variation on the energetic cost of climbing within humans. Twelve experienced rock climbers climbed on an indoor wall over a range of difficulty levels and velocities, with energy expenditure measured via respirometry. We found no effect of body mass or limb proportions on mass-specific cost of transport among subjects. Mass-specific cost of transport was negatively correlated with climbing velocity. Increased route difficulty was associated with slower climbing velocities and thus higher costs, but there was no statistically significant effect of route difficulty on energy expenditure independent of velocity. Finally, human climbing costs measured in this study were similar to published values for other primates, suggesting arboreal adaptations have a negligible effect on climbing efficiency.}, Doi = {10.1242/jeb.234567}, Key = {fds357316} } @article{fds355697, Author = {Rosinger, AY and Bethancourt, H and Swanson, ZS and Nzunza, R and Saunders, J and Dhanasekar, S and Kenney, WL and Hu, K and Douglass, MJ and Ndiema, E and Braun, DR and Pontzer, H}, Title = {Drinking water salinity is associated with hypertension and hyperdilute urine among Daasanach pastoralists in Northern Kenya.}, Journal = {The Science of the total environment}, Volume = {770}, Pages = {144667}, Year = {2021}, Month = {May}, url = {http://dx.doi.org/10.1016/j.scitotenv.2020.144667}, Abstract = {Water salinity is a growing global environmental health concern. However, little is known about the relation between water salinity and chronic health outcomes in non-coastal, lean populations. Daasanach pastoralists living in northern Kenya traditionally rely on milk, yet are experiencing socioecological changes and have expressed concerns about the saltiness of their drinking water. Therefore, this cross-sectional study conducted water quality analyses to examine how water salinity, along with lifestyle factors like milk intake, was associated with hypertension (blood pressure BP ≥140 mm Hg systolic or ≥90 mm Hg diastolic) and hyperdilute urine (urine specific gravity <1.003 g/mL, indicative of altered kidney function). We collected health biomarkers and survey data from 226 non-pregnant adults (46.9% male) aged 18+ from 134 households in 2019 along with participant observations in 2020. The salinity (total concentration of all dissolved salts) of reported drinking water from hand-dug wells in dry river beds, boreholes, and a pond ranged from 120 to 520 mg/L. Water from Lake Turkana and standpipes, which was only periodically used for consumption when no other drinking sources are available, ranged from 1100 to 2300 mg/L. Multiple logistic regression models with standard errors clustered on households indicate that each additional 100 mg/L of drinking water salinity was associated with 45% (95% CI: 1.09-1.93, P = 0.010) increased odds of hypertension and 33% (95% CI: 0.97-1.83, P = 0.075) increased odds of hyperdilute urine adjusted for confounders. Results were robust to multiple specifications of the models and sensitivity analyses. Daily milk consumption was associated with 61-63% (P < 0.01) lower odds of both outcomes. This considerable protective effect of milk intake may be due to the high potassium, magnesium, and calcium contents or the protective lifestyle considerations of moving with livestock. Our study results demonstrate that drinking water salinity may have critical health implications for blood pressure and kidney function even among lean, active pastoralists.}, Doi = {10.1016/j.scitotenv.2020.144667}, Key = {fds355697} } @article{fds355115, Author = {Wood, BM and Harris, JA and Raichlen, DA and Pontzer, H and Sayre, K and Sancilio, A and Berbesque, C and Crittenden, AN and Mabulla, A and McElreath, R and Cashdan, E and Jones, JH}, Title = {Gendered movement ecology and landscape use in Hadza hunter-gatherers.}, Journal = {Nature human behaviour}, Volume = {5}, Number = {4}, Pages = {436-446}, Year = {2021}, Month = {April}, url = {http://dx.doi.org/10.1038/s41562-020-01002-7}, Abstract = {Understanding how gendered economic roles structure space use is critical to evolutionary models of foraging behaviour, social organization and cognition. Here, we examine hunter-gatherer spatial behaviour on a very large scale, using GPS devices worn by Hadza foragers to record 2,078 person-days of movement. Theory in movement ecology suggests that the density and mobility of targeted foods should predict spatial behaviour and that strong gender differences should arise in a hunter-gatherer context. As predicted, we find that men walked further per day, explored more land, followed more sinuous paths and were more likely to be alone. These data are consistent with the ecology of male- and female-targeted foods and suggest that male landscape use is more navigationally challenging in this hunter-gatherer context. Comparisons of Hadza space use with space use data available for non-human primates suggest that the sexual division of labour likely co-evolved with increased sex differences in spatial behaviour and landscape use.}, Doi = {10.1038/s41562-020-01002-7}, Key = {fds355115} } @article{fds355436, Author = {Pontzer, H and Brown, MH and Wood, BM and Raichlen, DA and Mabulla, AZP and Harris, JA and Dunsworth, H and Hare, B and Walker, K and Luke, A and Dugas, LR and Schoeller, D and Plange-Rhule, J and Bovet, P and Forrester, TE and Thompson, ME and Shumaker, RW and Rothman, JM and Vogel, E and Sulistyo, F and Alavi, S and Prasetyo, D and Urlacher, SS and Ross, SR}, Title = {Evolution of water conservation in humans.}, Journal = {Current biology : CB}, Volume = {31}, Number = {8}, Pages = {1804-1810.e5}, Year = {2021}, Month = {April}, url = {http://dx.doi.org/10.1016/j.cub.2021.02.045}, Abstract = {To sustain life, humans and other terrestrial animals must maintain a tight balance of water gain and water loss each day.<sup>1-3</sup> However, the evolution of human water balance physiology is poorly understood due to the absence of comparative measures from other hominoids. While humans drink daily to maintain water balance, rainforest-living great apes typically obtain adequate water from their food and can go days or weeks without drinking<sup>4-6</sup>. Here, we compare isotope-depletion measures of water turnover (L/d) in zoo- and rainforest-sanctuary-housed apes (chimpanzees, bonobos, gorillas, and orangutans) with 5 diverse human populations, including a hunter-gatherer community in a semi-arid savannah. Across the entire sample, water turnover was strongly related to total energy expenditure (TEE, kcal/d), physical activity, climate (ambient temperature and humidity), and fat free mass. In analyses controlling for those factors, water turnover was 30% to 50% lower in humans than in other apes despite humans' greater sweating capacity. Water turnover in zoo and sanctuary apes was similar to estimated turnover in wild populations, as was the ratio of water intake to dietary energy intake (∼2.8 mL/kcal). However, zoo and sanctuary apes ingested a greater ratio of water to dry matter of food, which might contribute to digestive problems in captivity. Compared to apes, humans appear to target a lower ratio of water/energy intake (∼1.5 mL/kcal). Water stress due to changes in climate, diet, and behavior apparently led to previously unknown water conservation adaptations in hominin physiology.}, Doi = {10.1016/j.cub.2021.02.045}, Key = {fds355436} } @article{fds355114, Author = {Urlacher, SS and Snodgrass, JJ and Dugas, LR and Madimenos, FC and Sugiyama, LS and Liebert, MA and Joyce, CJ and Terán, E and Pontzer, H}, Title = {Childhood Daily Energy Expenditure Does Not Decrease with Market Integration and Is Not Related to Adiposity in Amazonia.}, Journal = {The Journal of nutrition}, Volume = {151}, Number = {3}, Pages = {695-704}, Year = {2021}, Month = {March}, url = {http://dx.doi.org/10.1093/jn/nxaa361}, Abstract = {<h4>Background</h4>Childhood overweight and obesity (OW/OB) is increasingly centered in low- and middle-income countries (LMICs) as rural populations experience market integration and lifeway change. Most explanatory studies have relied on imprecise estimates of children's energy expenditure, restricting understanding of the relative effects of changes in diet and energy expenditure on the development of OW/OB in transitioning contexts.<h4>Objectives</h4>This study used gold-standard measurements of children's energy expenditure to investigate the changes that underlie OW/OB and the nutrition/epidemiologic transition.<h4>Methods</h4>Cross-sectional data were collected from "rural" (n = 43) Shuar forager-horticulturalist children and their "peri-urban" (n = 34) Shuar counterparts (age 4-12 y) in Amazonian Ecuador. Doubly labeled water measurements of total energy expenditure (TEE; kcal/d), respirometry measurements of resting energy expenditure (REE; kcal/d), and measures of diet, physical activity, immune activity, and market integration were analyzed primarily using regression models.<h4>Results</h4>Peri-urban children had higher body fat percentage (+8.1%, P < 0.001), greater consumption of market-acquired foods (multiple P < 0.001), lower concentrations of immune activity biomarkers (multiple P < 0.05), and lower REE (-108 kcal/d, P = 0.002) than rural children. Despite these differences, peri-urban children's TEE was indistinguishable from that of rural children (P = 0.499). Moreover, although sample-wide IgG concentrations and household incomes predicted REE (both P < 0.05), no examined household, immune activity, or physical activity measures were related to children's overall TEE (all P > 0.09). Diet and energy expenditure associations with adiposity demonstrate that only reported consumption of market-acquired "protein" and "carbohydrate" foods predicted children's body fat levels (multiple P < 0.05).<h4>Conclusions</h4>Despite underlying patterns in REE, Shuar children's TEE is not reliably related to market integration and-unlike dietary measures-does not predict adiposity. These findings suggest a leading role of changing dietary intake in transitions to OW/OB in LMICs.}, Doi = {10.1093/jn/nxaa361}, Key = {fds355114} } @article{fds355706, Author = {Pontzer, H}, Title = {Metabolism myths}, Journal = {New Scientist}, Volume = {249}, Number = {3323}, Pages = {32-36}, Year = {2021}, Month = {February}, url = {http://dx.doi.org/10.1016/S0262-4079(21)00332-8}, Abstract = {To discover the truth about diet and exercise, we need to look at our evolutionary past, says anthropologist Herman Pontzer}, Doi = {10.1016/S0262-4079(21)00332-8}, Key = {fds355706} } @article{fds355708, Author = {Speakman, JR and Yamada, Y and Sagayama, H and Berman, ESF and Ainslie, PN and Andersen, LF and Anderson, LJ and Arab, L and Baddou, I and Bedu-Addo, K and Blaak, EE and Blanc, S and Bonomi, AG and Bouten, CVC and Bovet, P and Buchowski, MS and Butte, NF and Camps, SGJA and Close, GL and Cooper, JA and Creasy, SA and Das, SK and Cooper, R and Dugas, LR and Ebbeling, CB and Ekelund, U and Entringer, S and Forrester, T and Fudge, BW and Goris, AH and Gurven, M and Hambly, C and El Hamdouchi and A and Hoos, MB and Hu, S and Joonas, N and Joosen, AM and Katzmarzyk, P and Kempen, KP and Kimura, M and Kraus, WE and Kushner, RF and Lambert, EV and Leonard, WR and Lessan, N and Ludwig, DS and Martin, CK and Medin, AC and Meijer, EP and Morehen, JC and Morton, JP and Neuhouser, ML and Nicklas, TA and Ojiambo, RM and Pietiläinen, KH and Pitsiladis, YP and Plange-Rhule, J and Plasqui, G and Prentice, RL and Rabinovich, RA and Racette, SB and Raichlen, DA and Ravussin, E and Reynolds, RM and Roberts, SB and Schuit, AJ and Sjödin, AM and Stice, E and Urlacher, SS and Valenti, G and Van Etten and LM and Van Mil and EA and Wells, JCK and Wilson, G and Wood, BM and Yanovski, J and Yoshida, T and Zhang, X and Murphy-Alford, AJ and Loechl, CU and Melanson, EL and Luke, AH and Pontzer, H and Rood, J and Schoeller, DA and Westerterp, KR and Wong, WW and IAEA DLW database group}, Title = {A standard calculation methodology for human doubly labeled water studies.}, Journal = {Cell Rep Med}, Volume = {2}, Number = {2}, Pages = {100203}, Year = {2021}, Month = {February}, url = {http://dx.doi.org/10.1016/j.xcrm.2021.100203}, Abstract = {The doubly labeled water (DLW) method measures total energy expenditure (TEE) in free-living subjects. Several equations are used to convert isotopic data into TEE. Using the International Atomic Energy Agency (IAEA) DLW database (5,756 measurements of adults and children), we show considerable variability is introduced by different equations. The estimated rCO2 is sensitive to the dilution space ratio (DSR) of the two isotopes. Based on performance in validation studies, we propose a new equation based on a new estimate of the mean DSR. The DSR is lower at low body masses (<10 kg). Using data for 1,021 babies and infants, we show that the DSR varies non-linearly with body mass between 0 and 10 kg. Using this relationship to predict DSR from weight provides an equation for rCO2 over this size range that agrees well with indirect calorimetry (average difference 0.64%; SD = 12.2%). We propose adoption of these equations in future studies.}, Doi = {10.1016/j.xcrm.2021.100203}, Key = {fds355708} } @article{fds350297, Author = {Bethancourt, HJ and Swanson, ZS and Nzunza, R and Huanca, T and Conde, E and Kenney, WL and Young, SL and Ndiema, E and Braun, D and Pontzer, H and Rosinger, AY}, Title = {Hydration in relation to water insecurity, heat index, and lactation status in two small-scale populations in hot-humid and hot-arid environments.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {33}, Number = {1}, Pages = {e23447}, Year = {2021}, Month = {January}, url = {http://dx.doi.org/10.1002/ajhb.23447}, Abstract = {<h4>Objectives</h4>This study compared the prevalence of concentrated urine (urine specific gravity ≥1.021), an indicator of hypohydration, across Tsimane' hunter-forager-horticulturalists living in hot-humid lowland Bolivia and Daasanach agropastoralists living in hot-arid Northern Kenya. It tested the hypotheses that household water and food insecurity would be associated with higher odds of hypohydration.<h4>Methods</h4>This study collected spot urine samples and corresponding weather data along with data on household water and food insecurity, demographics, and health characteristics among 266 Tsimane' households (N = 224 men, 235 women, 219 children) and 136 Daasanach households (N = 107 men, 120 women, 102 children).<h4>Results</h4>The prevalence of hypohydration among Tsimane' men (50.0%) and women (54.0%) was substantially higher (P < .001) than for Daasanach men (15.9%) and women (17.5%); the prevalence of hypohydration among Tsimane' (37.0%) and Daasanach (31.4%) children was not significantly different (P = .33). Multiple logistic regression models suggested positive but not statistically significant trends between household water insecurity and odds of hypohydration within populations, yet some significant joint effects of water and food insecurity were observed. Heat index (2°C) was associated with a 23% (95% confidence interval [CI]: 1.09-1.40, P = .001), 34% (95% CI: 1.18-1.53, P < .0005), and 23% (95% CI: 1.04-1.44, P = .01) higher odds of hypohydration among Tsimane' men, women, and children, respectively, and a 48% (95% CI: 1.02-2.15, P = .04) increase in the odds among Daasanach women. Lactation status was also associated with hypohydration among Tsimane' women (odds ratio = 3.35, 95% CI: 1.62-6.95, P = .001).<h4>Conclusion</h4>These results suggest that heat stress and reproductive status may have a greater impact on hydration status than water insecurity across diverse ecological contexts.}, Doi = {10.1002/ajhb.23447}, Key = {fds350297} } @article{fds355705, Author = {Pontzer, H}, Title = {Metabolism myths}, Journal = {NEW SCIENTIST}, Volume = {245}, Number = {3323}, Pages = {32-36}, Year = {2021}, Key = {fds355705} } @article{fds353322, Author = {Pontzer, H}, Title = {Ranging Ecology: The View from Above.}, Journal = {Current biology : CB}, Volume = {30}, Number = {22}, Pages = {R1378-R1380}, Year = {2020}, Month = {November}, url = {http://dx.doi.org/10.1016/j.cub.2020.09.029}, Abstract = {Animals use a variety of strategies to navigate their world, but few are thought to have detailed mental maps of their landscapes. New research with our closest relatives suggests chimpanzees may use cognitive maps to find the most energy efficient routes.}, Doi = {10.1016/j.cub.2020.09.029}, Key = {fds353322} } @article{fds355116, Author = {Pontzer, H and Rimbach, R and Paltan, J and Ivory, EL and Kendall, CJ}, Title = {Air temperature and diet influence body composition and water turnover in zoo-living African elephants (Loxodonta africana).}, Journal = {Royal Society open science}, Volume = {7}, Number = {11}, Pages = {201155}, Year = {2020}, Month = {November}, url = {http://dx.doi.org/10.1098/rsos.201155}, Abstract = {African elephants, the largest land animal, face particular physiological challenges in captivity and the wild. Captive elephants can become over- or under-conditioned with inadequate exercise and diet management. Few studies have quantified body composition or water turnover in elephants, and none to date have examined longitudinal responses to changes in diet or air temperature. Using the stable isotope deuterium oxide (<sup>2</sup>H<sub>2</sub>O), we investigated changes in body mass, estimated fat-free mass (FFM, including fat-free gut content) and body fat in response to a multi-year intervention that reduced dietary energy density for adult African elephants housed at the North Carolina Zoo. We also examined the relationship between air temperature and water turnover. Deuterium dilution and depletion rates were assayed via blood samples and used to calculate body composition and water turnover in two male and three female African elephants at six intervals over a 3-year period. Within the first year after the dietary intervention, there was an increase in overall body mass, a reduction in body fat percentage and an increase in FFM. However, final values of both body fat percentage and FFM were similar to initial values. Water turnover (males: 359 ± 9 l d<sup>-1</sup>; females: 241 ± 28 l d<sup>-1</sup>) was consistent with the allometric scaling of water use in other terrestrial mammals. Water turnover increased with outdoor air temperature. Our study highlights the physiological water dependence of elephants and shows that individuals have to drink every 2-3 days to avoid critical water loss of approximately 10% body mass in hot conditions.}, Doi = {10.1098/rsos.201155}, Key = {fds355116} } @article{fds355117, Author = {Pontzer, H and Rimbach, R and Paltan, J and Ivory, EL and Kendall, CJ}, Title = {Air temperature and diet influence body composition and water turnover in zoo-living African elephants (Loxodonta africana): Water turnover in African elephants}, Journal = {Royal Society Open Science}, Volume = {7}, Number = {11}, Year = {2020}, Month = {November}, url = {http://dx.doi.org/10.1098/rsos.201155}, Abstract = {African elephants, the largest land animal, face particular physiological challenges in captivity and the wild. Captive elephants can become over- or under-conditioned with inadequate exercise and diet management. Few studies have quantified body composition or water turnover in elephants, and none to date have examined longitudinal responses to changes in diet or air temperature. Using the stable isotope deuterium oxide (2 H 2 O), we investigated changes in body mass, estimated fat-free mass (FFM, including fat-free gut content) and body fat in response to a multi-year intervention that reduced dietary energy density for adult African elephants housed at the North Carolina Zoo. We also examined the relationship between air temperature and water turnover. Deuterium dilution and depletion rates were assayed via blood samples and used to calculate body composition and water turnover in two male and three female African elephants at six intervals over a 3-year period. Within the first year after the dietary intervention, there was an increase in overall body mass, a reduction in body fat percentage and an increase in FFM. However, final values of both body fat percentage and FFM were similar to initial values. Water turnover (males: 359 ± 9 l d -1; females: 241 ± 28 l d -1) was consistent with the allometric scaling of water use in other terrestrial mammals. Water turnover increased with outdoor air temperature. Our study highlights the physiological water dependence of elephants and shows that individuals have to drink every 2-3 days to avoid critical water loss of approximately 10% body mass in hot conditions.}, Doi = {10.1098/rsos.201155}, Key = {fds355117} } @article{fds355118, Author = {Sayre, MK and Pontzer, H and Alexander, GE and Wood, BM and Pike, IL and Mabulla, AZP and Raichlen, DA}, Title = {Ageing and physical function in East African foragers and pastoralists.}, Journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, Volume = {375}, Number = {1811}, Pages = {20190608}, Year = {2020}, Month = {November}, url = {http://dx.doi.org/10.1098/rstb.2019.0608}, Abstract = {Human lifespans are exceptionally long compared with those of other primates. A key element in exploring the evolution of human longevity is understanding how modern humans grow older. Our current understanding of common age-related changes in human health and function stems mostly from studies in industrialized societies, where older adulthood is often associated with an increased incidence of chronic diseases. However, individuals who engage in different lifestyles across industrialized and non-industrialized contexts may display variance in age-related changes in health and function. Here, we explore aspects of physical function in a non-industrialized context using three objective measures of physical function. We assessed physical activity levels, walking endurance and muscle strength in two East African populations: Hadza hunter-gatherers in Tanzania and Pokot pastoralists in Kenya. Both Hadza and Pokot participants displayed significant age-related differences in most, but not all, functional measures. Our results suggest that some age-related differences in physical function seen in industrialized contexts could be consistently experienced by most humans, while other age-related differences may vary across populations. Studies of ageing should expand to include a broad range of populations so we can create a more comprehensive understanding of how senescence varies across different lifestyle contexts. This article is part of the theme issue 'Evolution of the primate ageing process'.}, Doi = {10.1098/rstb.2019.0608}, Key = {fds355118} } @article{fds355119, Author = {Pontzer, H and Raichlen, D}, Title = {How to sit}, Journal = {New Scientist}, Volume = {247}, Number = {3291}, Pages = {28-32}, Year = {2020}, Month = {July}, url = {http://dx.doi.org/10.1016/S0262-4079(20)31249-5}, Abstract = {Far from being a fast track to ill-health, sitting can be good for us, find Herman Pontzer and David Raichlen. The trick is how you do it}, Doi = {10.1016/S0262-4079(20)31249-5}, Key = {fds355119} } @article{fds350300, Author = {Raichlen, DA and Pontzer, H and Zderic, TW and Harris, JA and Mabulla, AZP and Hamilton, MT and Wood, BM}, Title = {Sitting, squatting, and the evolutionary biology of human inactivity.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {117}, Number = {13}, Pages = {7115-7121}, Year = {2020}, Month = {March}, url = {http://dx.doi.org/10.1073/pnas.1911868117}, Abstract = {Recent work suggests human physiology is not well adapted to prolonged periods of inactivity, with time spent sitting increasing cardiovascular disease and mortality risk. Health risks from sitting are generally linked with reduced levels of muscle contractions in chair-sitting postures and associated reductions in muscle metabolism. These inactivity-associated health risks are somewhat paradoxical, since evolutionary pressures tend to favor energy-minimizing strategies, including rest. Here, we examined inactivity in a hunter-gatherer population (the Hadza of Tanzania) to understand how sedentary behaviors occur in a nonindustrial economic context more typical of humans' evolutionary history. We tested the hypothesis that nonambulatory rest in hunter-gatherers involves increased muscle activity that is different from chair-sitting sedentary postures used in industrialized populations. Using a combination of objectively measured inactivity from thigh-worn accelerometers, observational data, and electromygraphic data, we show that hunter-gatherers have high levels of total nonambulatory time (mean ± SD = 9.90 ± 2.36 h/d), similar to those found in industrialized populations. However, nonambulatory time in Hadza adults often occurs in postures like squatting, and we show that these "active rest" postures require higher levels of lower limb muscle activity than chair sitting. Based on our results, we introduce the Inactivity Mismatch Hypothesis and propose that human physiology is likely adapted to more consistently active muscles derived from both physical activity and from nonambulatory postures with higher levels of muscle contraction. Interventions built on this model may help reduce the negative health impacts of inactivity in industrialized populations.}, Doi = {10.1073/pnas.1911868117}, Key = {fds350300} } @article{fds370085, Author = {Wood, BM and Pontzer, H and Harris, JA and Mabulla, AZP and Hamilton, MT and Zderic, TW and Beheim, BA and Raichlen, DA}, Title = {Step Counts From Satellites: Methods for Integrating Accelerometer and GPS Data for More Accurate Measures of Pedestrian Travel}, Journal = {Journal for the Measurement of Physical Behaviour}, Volume = {3}, Number = {1}, Pages = {58-66}, Year = {2020}, Month = {March}, url = {http://dx.doi.org/10.1123/jmpb.2019-0016}, Abstract = {The rapid adoption of lightweight activity tracking sensors demonstrates that precise measures of physical activity hold great value for a wide variety of applications. The corresponding growth of physical activity data creates an urgent need for methods to integrate such data. In this paper, we demonstrate methods for 1) synchronizing accelerometer and Global Positioning System (GPS) data with optimal corrections for device-related time drift, and 2) producing principled estimates of step counts from GPS data. These methods improve the accuracy of time-resolved physical activity measures and permit pedestrian travel from either sensor to be expressed in terms of a common currency, step counts. We show that sensor-based estimates of step length correspond well with expectations based on independent measures, and functional relationships between step length, height, and movement speed expected from biomechanical models. Using 123 person-days of data in which Hadza hunter-gatherers wore both GPS devices and accelerometers, we find that GPS-based estimates of daily step counts have a good correspondence with accelerometer-recorded values. A multivariate linear model predicting daily step counts from distance walked, mean movement speed, and height has an R2 value of 0.96 and a mean absolute percent error of 16.8% (mean absolute error = 1,354 steps; mean steps per day = 15,800; n = 123). To best represent step count estimation error, we fit a Bayesian model and plot the distributions of step count estimates it generates. Our methods more accurately situate accelerometer-based measures of physical activity in space and time, and provide new avenues for comparative research in biomechanics and human movement ecology.}, Doi = {10.1123/jmpb.2019-0016}, Key = {fds370085} } @article{fds350311, Author = {Stoner, L and Pontzer, H and Barone Gibbs and B and Moore, JB and Castro, N and Skidmore, P and Lark, S and Williams, MA and Hamlin, MJ and Faulkner, J}, Title = {Fitness and Fatness Are Both Associated with Cardiometabolic Risk in Preadolescents.}, Journal = {The Journal of pediatrics}, Volume = {217}, Pages = {39-45.e1}, Year = {2020}, Month = {February}, url = {http://dx.doi.org/10.1016/j.jpeds.2019.09.076}, Abstract = {<h4>Objective</h4>To determine the associations between cardiorespiratory fitness (CRF) and fatness (overweight-obesity) with cardiometabolic disease risk among preadolescent children.<h4>Study design</h4>This cross-sectional study recruited 392 children (50% female, 8-10 years of age). Overweight-obesity was classified according to 2007 World Health Organization criteria for body mass index. High CRF was categorized as a maximum oxygen uptake, determined using a shuttle run test, exceeding 35 mL·kg<sup>-1</sup>·minute<sup>-1</sup> in girls and 42 mL·kg<sup>-1</sup>·minute<sup>-1</sup> in boys. Eleven traditional and novel cardiometabolic risk factors were measured including lipids, glucose, glycated hemoglobin, peripheral and central blood pressure, and arterial wave reflection. Factor analysis identified underlying cardiometabolic disease risk factors and a cardiometabolic disease risk summary score. Two-way analysis of covariance determined the associations between CRF and fatness with cardiometabolic disease risk factors.<h4>Results</h4>Factor analysis revealed four underlying factors: blood pressure, cholesterol, vascular health, and carbohydrate-metabolism. Only CRF was significantly (P = .001) associated with the blood pressure factor. Only fatness associated with vascular health (P = .010) and carbohydrate metabolism (P = .005) factors. For the cardiometabolic disease risk summary score, there was an interaction effect. High CRF was associated with decreased cardiometabolic disease risk in overweight-obese but not normal weight children (P = .006). Conversely, high fatness was associated with increased cardiometabolic disease risk in low fit but not high fit children (P < .001).<h4>Conclusions</h4>In preadolescent children, CRF and fatness explain different components of cardiometabolic disease risk. However, high CRF may moderate the relationship between fatness and cardiometabolic disease risk.<h4>Trial registration</h4>ACTRN 12614000433606.}, Doi = {10.1016/j.jpeds.2019.09.076}, Key = {fds350311} } @article{fds350312, Author = {Hora, M and Pontzer, H and Wall-Scheffler, CM and Sládek, V}, Title = {Dehydration and persistence hunting in Homo erectus.}, Journal = {Journal of human evolution}, Volume = {138}, Pages = {102682}, Year = {2020}, Month = {January}, url = {http://dx.doi.org/10.1016/j.jhevol.2019.102682}, Abstract = {Persistence hunting has been suggested to be a key strategy for meat acquisition in Homo erectus. However, prolonged locomotion in hot conditions is associated with considerable water losses due to sweating. Consequently, dehydration has been proposed to be a critical limiting factor, effectively curtailing the usefulness of persistence hunting prior to the invention of water containers. In this study, we aimed to determine the extent to which dehydration limited persistence hunting in H. erectus. We simulated ambient conditions and spatiotemporal characteristics of nine previously reported persistence hunts in the Kalahari. We used a newly developed and validated heat exchange model to estimate the water loss in H. erectus and a recent Kalahari hunter. Water loss equivalent to 10% of the hunter's body mass was considered the physiological limit of a hunt with no drinking. Our criterion for ruling dehydration out of being a limit for persistence hunting was the ability to hunt without drinking for at least 5 h, as this was the longest duration reported for a successful persistence hunt of large prey. Our results showed that H. erectus would reach the dehydration limit in 5.5-5.7 h of persistence hunting at the reported Kalahari conditions, which we argue represent a conservative model also for Early Pleistocene East Africa. Maximum hunt duration without drinking was negatively related to the relative body surface area of the hunter. Moreover, H. erectus would be able to persistence hunt over 5 h without drinking despite possible deviations from modern-like heat dissipation capacity, aerobic capacity, and locomotor economy. We conclude that H. erectus could persistence hunt large prey without the need to carry water.}, Doi = {10.1016/j.jhevol.2019.102682}, Key = {fds350312} } @article{fds350313, Author = {Swanson, ZS and Pontzer, H}, Title = {Water turnover among human populations: Effects of environment and lifestyle.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {32}, Number = {1}, Pages = {e23365}, Year = {2020}, Month = {January}, url = {http://dx.doi.org/10.1002/ajhb.23365}, Abstract = {<h4>Objectives</h4>To discuss the environmental and lifestyle determinants of water balance in humans and identify the gaps in current research regarding water use across populations.<h4>Methods</h4>We investigated intraspecific variation in water turnover by comparing data derived from a large number of human populations measured using either dietary survey or isotope tracking. We also used published data from a broad sample of mammalian species to identify the interspecific relationship between body mass and water turnover.<h4>Results</h4>Water facilitates nearly all physiological tasks and water turnover is strongly related to body size among mammals (r2=0.90). Within humans, however, the effect of body size is small. Instead, water intake and turnover vary with lifestyle and environmental conditions. Notably, despite living physically active lives in conditions that should increase water demands, the available measures of water intake and turnover among small-scale farming and pastoralist communities are broadly similar to those in less active, industrialized populations.<h4>Conclusions</h4>More work is required to better understand the environmental, behavioral, and cultural determinants of water turnover in humans living across a variety of ecosystems and lifestyles. The results of such work are made more vital by the climate crisis, which threatens the water security of millions around the globe.}, Doi = {10.1002/ajhb.23365}, Key = {fds350313} } @article{fds350314, Author = {Urlacher, SS and Snodgrass, JJ and Dugas, LR and Sugiyama, LS and Liebert, MA and Joyce, CJ and Pontzer, H}, Title = {Constraint and trade-offs regulate energy expenditure during childhood.}, Journal = {Science advances}, Volume = {5}, Number = {12}, Pages = {eaax1065}, Year = {2019}, Month = {December}, url = {http://dx.doi.org/10.1126/sciadv.aax1065}, Abstract = {Children's metabolic energy expenditure is central to evolutionary and epidemiological frameworks for understanding variation in human phenotype and health. Nonetheless, the impact of a physically active lifestyle and heavy burden of infectious disease on child metabolism remains unclear. Using energetic, activity, and biomarker measures, we show that Shuar forager-horticulturalist children of Amazonian Ecuador are ~25% more physically active and, in association with immune activity, have ~20% greater resting energy expenditure than children from industrial populations. Despite these differences, Shuar children's total daily energy expenditure, measured using doubly labeled water, is indistinguishable from industrialized counterparts. Trade-offs in energy allocation between competing physiological tasks, within a constrained energy budget, appear to shape childhood phenotypic variation (e.g., patterns of growth). These trade-offs may contribute to the lifetime obesity and metabolic health disparities that emerge during rapid economic development.}, Doi = {10.1126/sciadv.aax1065}, Key = {fds350314} } @article{fds346486, Author = {Horiuchi, M and Kirihara, Y and Fukuoka, Y and Pontzer, H}, Title = {Sex differences in respiratory and circulatory cost during hypoxic walking: potential impact on oxygen saturation.}, Journal = {Scientific reports}, Volume = {9}, Number = {1}, Pages = {9550}, Year = {2019}, Month = {July}, url = {http://dx.doi.org/10.1038/s41598-019-44844-6}, Abstract = {Energy expenditure (EE) during treadmill walking under normal conditions (normobaric normoxia, 21% O<sub>2</sub>) and moderate hypoxia (13% O<sub>2</sub>) was measured. Ten healthy young men and ten healthy young women walked on a level (0°) gradient a range of speeds (0.67-1.67 m s<sup>-1</sup>). During walking, there were no significant differences in reductions in arterial oxygen saturation (SpO<sub>2</sub>) between the sexes. The hypoxia-induced increase in EE, heart rate (HR [bpm]) and ventilation ([Formula: see text] [L min<sup>-1</sup>]) were calculated. Using a multivariate model that combined EE, [Formula: see text], and HR to predict ΔSpO<sub>2</sub> (hypoxia-induced reduction), a very strong fit model both for men (r<sup>2</sup> = 0.900, P < 0.001) and for women was obtained (r<sup>2</sup> = 0.957, P < 0.001). The contributions of EE, VE, and HR to ΔSpO<sub>2</sub> were markedly different between men and women. [Formula: see text] and EE had a stronger effect on ΔSpO<sub>2</sub> in women ([Formula: see text]: 4.1% in women vs. 1.7% in men; EE: 28.1% in women vs. 15.8% in men), while HR had a greater effect in men (82.5% in men and 67.9% in women). These findings suggested that high-altitude adaptation in response to hypoxemia has different underlying mechanisms between men and women. These results can help to explain how to adapt high-altitude for men and women, respectively.}, Doi = {10.1038/s41598-019-44844-6}, Key = {fds346486} } @article{fds346487, Author = {Pontzer, H}, Title = {Step on it}, Journal = {New Scientist}, Volume = {242}, Number = {3234}, Pages = {34-37}, Year = {2019}, Month = {June}, url = {http://dx.doi.org/10.1016/S0262-4079(19)31086-3}, Abstract = {We know exercise is good for us. But how much do we need? Anthropologist Herman Pontzer has the answer}, Doi = {10.1016/S0262-4079(19)31086-3}, Key = {fds346487} } @article{fds346488, Author = {Thurber, C and Dugas, LR and Ocobock, C and Carlson, B and Speakman, JR and Pontzer, H}, Title = {Extreme events reveal an alimentary limit on sustained maximal human energy expenditure.}, Journal = {Science advances}, Volume = {5}, Number = {6}, Pages = {eaaw0341}, Year = {2019}, Month = {June}, url = {http://dx.doi.org/10.1126/sciadv.aaw0341}, Abstract = {The limits on maximum sustained energy expenditure are unclear but are of interest because they constrain reproduction, thermoregulation, and physical activity. Here, we show that sustained expenditure in humans, measured as maximum sustained metabolic scope (SusMS), is a function of event duration. We compiled measurements of total energy expenditure (TEE) and basal metabolic rate (BMR) from human endurance events and added new data from adults running ~250 km/week for 20 weeks in a transcontinental race. For events lasting 0.5 to 250+ days, SusMS decreases curvilinearly with event duration, plateauing below 3× BMR. This relationship differs from that of shorter events (e.g., marathons). Incorporating data from overfeeding studies, we find evidence for an alimentary energy supply limit in humans of ~2.5× BMR; greater expenditure requires drawing down the body's energy stores. Transcontinental race data suggest that humans can partially reduce TEE during long events to extend endurance.}, Doi = {10.1126/sciadv.aaw0341}, Key = {fds346488} } @article{fds342247, Author = {Gurven, M and Trumble, B and Stieglitz, J and Cummings, D and Kaplan, H and Blackwell, AD and Yetish, G and Pontzer, H}, Title = {Methodological differences cannot explain associations between health, anthropometrics, and excess resting metabolic rate.}, Journal = {American journal of physical anthropology}, Volume = {169}, Number = {1}, Pages = {197-198}, Year = {2019}, Month = {May}, url = {http://dx.doi.org/10.1002/ajpa.23811}, Doi = {10.1002/ajpa.23811}, Key = {fds342247} } @article{fds342246, Author = {Rosinger, AY and Pontzer, H and Raichlen, DA and Wood, BM and Tanner, SN and Sands, JM}, Title = {Age-related decline in urine concentration may not be universal: Comparative study from the U.S. and two small-scale societies.}, Journal = {American journal of physical anthropology}, Volume = {168}, Number = {4}, Pages = {705-716}, Year = {2019}, Month = {April}, url = {http://dx.doi.org/10.1002/ajpa.23788}, Abstract = {<h4>Objectives</h4>Evidence from industrialized populations suggests that urine concentrating ability declines with age. However, lifestyle factors including episodic protein intake and low hypertension may help explain differences between populations. Whether this age-related decline occurs among small-scale populations with active lifestyles and non-Western diets is unknown. We test the universality of age-related urine concentration decline.<h4>Materials and methods</h4>We used urine specific gravity (Usg) and urine osmolality (Uosm) data from 15,055 U.S. nonpregnant adults without kidney failure aged 18-80 in 2007-2012 participating in the National Health and Nutrition Examination Survey (NHANES). We tested the relationship of age on urine concentration biomarkers with multiple linear regressions using survey commands. We compared results to longitudinal data on Usg from 116 Tsimane' forager-horticulturalists (266 observations) adults aged 18-83 in 2013-2014 from Lowland Bolivia, and to 38 Hadza hunter-gatherers (156 observations) aged 18-75 in 2010-2015 from Tanzania using random-effects panel linear regressions.<h4>Results</h4>Among U.S. adults, age was significantly negatively associated with Usg (Adjusted beta [B] = -0.0009 g/mL/10 years; SE = 0.0001; p < 0.001) and Uosm (B = -28.1 mOsm/kg/10 yr; SE = 2.4; p < 0.001). In contrast, among Tsimane' (B = 0.0003 g/mL/10 yr; SE = 0.0002; p = 0.16) and Hadza (B = -0.0004 g/mL/10 yr; SE = 0.0004; p = 0.29) age was not associated with Usg. Older Tsimane' and Hadza exhibited similar within-individual variability in Usg equivalent to younger adults.<h4>Discussion</h4>While U.S. adults exhibited age-related declines in urine concentration, Tsimane' and Hadza adults did not exhibit the same statistical decline in Usg. Mismatches between evolved physiology and modern environments in lifestyle may affect kidney physiology and disease risk.}, Doi = {10.1002/ajpa.23788}, Key = {fds342246} } @article{fds342881, Author = {Christopher, L and Madimenos, FC and Bribiescas, RG and Urlacher, SS and Snodgrass, JJ and Sugiyama, LS and Pontzer, H}, Title = {High energy requirements and water throughput of adult Shuar forager-horticulturalists of Amazonian Ecuador.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {31}, Number = {2}, Pages = {e23223}, Year = {2019}, Month = {March}, url = {http://dx.doi.org/10.1002/ajhb.23223}, Abstract = {<h4>Objectives</h4>We measured total energy expenditure (TEE; kcal/d) and water throughput (L/d) among Shuar forager-horticulturalists from Amazonian Ecuador to compare their daily energy and water demands to adults in other small-scale and industrialized populations.<h4>Methods</h4>TEE and water throughput were measured using the doubly labeled water method among 15 Shuar adults (eight women, seven men; age range 18-60 years) living in a relatively remote village. We used multiple regression to assess the effects of anthropometric variables (body size, fat free mass, age, and sex) on TEE and water throughput. We also compared Shuar TEE and water throughput to those of other small-scale and industrialized societies.<h4>Results</h4>TEE among Shuar adults (men: 4141 ± 645 kcal/d, women: 2536 ± 281 kcal/d) was most strongly correlated with fat free mass. Estimated physical activity levels (PAL) calculated as (TEE/estimated BMR), were greater for men (2.34 ± 0.29) than women (1.83 ± 0.14, P < 0.001). Water throughput was also greater among Shuar men (9.37 ± 2.34 L/d) than women (4.76 ± 0.36 L/d, P < 0.001). Shuar TEE and water throughput were elevated compared to adults in industrialized populations.<h4>Discussion</h4>TEE and PAL of Shuar men are among the highest recorded during normal daily life, and likely reflect both high levels of physical activity and cultural dietary practices. Drinking large amounts of chicha, a traditional carbohydrate-rich drink made from manioc, likely contributes to the high levels of water throughput among Shuar men, and may contribute to elevated TEE.}, Doi = {10.1002/ajhb.23223}, Key = {fds342881} } @article{fds350315, Author = {Pontzer, H}, Title = {EVOLVED TO EXERCISE}, Journal = {SCIENTIFIC AMERICAN}, Volume = {320}, Number = {1}, Pages = {24-31}, Publisher = {SPRINGER}, Year = {2019}, Month = {January}, Key = {fds350315} } @article{fds350316, Author = {Speakman, JR and Pontzer, H and Rood, J and Sagayama, H and Schoeller, DA and Westerterp, KR and Wong, WW and Yamada, Y and Loechl, C and Murphy-Alford, AJ}, Title = {The International Atomic Energy Agency International Doubly Labelled Water Database: Aims, Scope and Procedures.}, Journal = {Annals of nutrition & metabolism}, Volume = {75}, Number = {2}, Pages = {114-118}, Year = {2019}, Month = {January}, url = {http://dx.doi.org/10.1159/000503668}, Abstract = {<h4>Background</h4>The doubly labelled water (DLW) method is an isotope-based technique that quantifies total energy expenditure (TEE) over periods of 1-3 weeks from the differential elimination of stable isotopes of oxygen and hydrogen. The method was invented in the 1950s, but limited ability to measure low isotope enrichments combined with the high cost of isotopes meant it only became feasible to use in humans in the 1980s. It is still relatively expensive to use, and alone small samples are unable to tackle some of the important questions surrounding energy balance such as how have expenditures changed over time and how do expenditures differ with age, between sexes and in different environments?<h4>Summary</h4>By combining information across studies, answers to such questions may be possible. The International Atomic Energy Agency (IAEA) DLW database was established to pool DLW data across multiple studies. It was initiated by the main labs currently using the method and is hosted by the IAEA. At present, the database contains 6,621 measures of TEE by DLW from individuals in 23 countries, along with various additional data on the study participants. Key Messages: The IAEA DLW database is a key resource enabling future studies of energy demands.}, Doi = {10.1159/000503668}, Key = {fds350316} } @article{fds342257, Author = {Pontzer, H and Wood, BM and Raichlen, DA}, Title = {Hunter-gatherers as models in public health.}, Journal = {Obesity reviews : an official journal of the International Association for the Study of Obesity}, Volume = {19 Suppl 1}, Pages = {24-35}, Year = {2018}, Month = {December}, url = {http://dx.doi.org/10.1111/obr.12785}, Abstract = {Hunter-gatherer populations are remarkable for their excellent metabolic and cardiovascular health and thus are often used as models in public health, in an effort to understand the root, evolutionary causes of non-communicable diseases. Here, we review recent work on health, activity, energetics and diet among hunter-gatherers and other small-scale societies (e.g. subsistence farmers, horticulturalists and pastoralists), as well as recent fossil and archaeological discoveries, to provide a more comprehensive perspective on lifestyle and health in these populations. We supplement these analyses with new data from the Hadza, a hunter-gatherer population in northern Tanzania. Longevity among small-scale populations approaches that of industrialized populations, and metabolic and cardiovascular disease are rare. Obesity prevalence is very low (<5%), and mean body fat percentage is modest (women: 24-28%, men: 9-18%). Activity levels are high, exceeding 100 min d<sup>-1</sup> of moderate and vigorous physical activity, but daily energy expenditures are similar to industrialized populations. Diets in hunter-gatherer and other small-scale societies tend to be less energy dense and richer in fibre and micronutrients than modern diets but are not invariably low carbohydrate as sometimes argued. A more integrative understanding of hunter-gatherer health and lifestyle, including elements beyond diet and activity, will improve public health efforts in industrialized populations.}, Doi = {10.1111/obr.12785}, Key = {fds342257} } @article{fds342258, Author = {Pontzer, H}, Title = {Method and rationale for recalculating dilution spaces to a single, common time point in doubly labeled water studies.}, Journal = {European journal of clinical nutrition}, Volume = {72}, Number = {12}, Pages = {1620-1624}, Year = {2018}, Month = {December}, url = {http://dx.doi.org/10.1038/s41430-018-0361-1}, Abstract = {<h4>Background</h4>The doubly labeled water (DLW) method has become widely used in studies of energy expenditure and body composition. Researchers differ in the analytical methods used to calculate the dilution spaces for deuterium and oxygen-18. Some determine dilution spaces using isotope enrichments extrapolated to the instant of dosing with DLW (slope-intercept method), but others use measured enrichments from body water samples obtained 3-10 h after dosing (plateau method). These differences limit the comparability of analyses across labs.<h4>Methods</h4>I derive a simple mathematical approach for recalculating reported dilution spaces to any time point post dosing, using reported dilution spaces and rates of isotope depletion. Simulated data are used to examine the effects of different dilution space protocols.<h4>Results</h4>Recalculating dilution spaces enables researchers to determine outcome variables of interest (e.g., total body water, energy expenditure, and water throughput) from different labs under a unified protocol for determining dilution spaces, and improves comparisons among studies.<h4>Conclusions</h4>Differences between dilution space protocols can lead to substantial differences in outcome variables of interest in DLW studies. When comparing results of DLW studies that employ different dilution space protocols, dilution spaces should be recalculated for a common time point, and outcome variables recalculated as needed, prior to comparison across studies.}, Doi = {10.1038/s41430-018-0361-1}, Key = {fds342258} } @article{fds339328, Author = {Pontzer, H}, Title = {Energy Constraint as a Novel Mechanism Linking Exercise and Health.}, Journal = {Physiology (Bethesda, Md.)}, Volume = {33}, Number = {6}, Pages = {384-393}, Year = {2018}, Month = {November}, url = {http://dx.doi.org/10.1152/physiol.00027.2018}, Abstract = {Humans and other species adapt dynamically to changes in daily physical activity, maintaining total energy expenditure within a narrow range. Chronic exercise thus suppresses other physiological activity, including immunity, reproduction, and stress response. This exercise-induced downregulation improves health at moderate levels of physical activity but can be detrimental at extreme workloads.}, Doi = {10.1152/physiol.00027.2018}, Key = {fds339328} } @article{fds337752, Author = {Pontzer, H}, Title = {Alternative Energy Physiological evolution in the human lineage}, Journal = {NATURAL HISTORY}, Volume = {126}, Number = {8}, Pages = {37-39}, Publisher = {NATURAL HISTORY MAGAZINE}, Year = {2018}, Month = {September}, Key = {fds337752} } @article{fds337753, Author = {Gagnon, CM and Steiper, ME and Pontzer, H}, Title = {Elite swimmers do not exhibit a body mass index trade-off across a wide range of event distances.}, Journal = {Proceedings. Biological sciences}, Volume = {285}, Number = {1882}, Pages = {20180684}, Year = {2018}, Month = {July}, url = {http://dx.doi.org/10.1098/rspb.2018.0684}, Abstract = {There is a trade-off reflected in the contrasting phenotypes of elite long-distance runners, who are typically leaner, and elite sprinters, who are usually more heavily muscled. It is unclear, however, whether and how swimmers' bodies vary across event distances from the 50 m swim, which is about a 20-30 s event, to the 10 000 m marathon swim, which is about a 2 h event. We examined data from the 2012 Olympics to test whether swimmers' phenotypes differed across event distances. We show that across all swimming event distances, from the 50 m sprint to the 10 000 m marathon, swimmers converge on a single optimal body mass index (BMI) in men's and women's events, in marked contrast with the strong inverse relationship between BMI and event distance found in runners. The absence of a speed-endurance trade-off in the body proportions of swimmers indicates a fundamental difference in design pressures and performance capability in terrestrial versus aquatic environments.}, Doi = {10.1098/rspb.2018.0684}, Key = {fds337753} } @article{fds337754, Author = {Finestone, EM and Brown, MH and Ross, SR and Pontzer, H}, Title = {Great ape walking kinematics: Implications for hominoid evolution.}, Journal = {American journal of physical anthropology}, Volume = {166}, Number = {1}, Pages = {43-55}, Year = {2018}, Month = {May}, url = {http://dx.doi.org/10.1002/ajpa.23397}, Abstract = {<h4>Objectives</h4>Great apes provide a point of reference for understanding the evolution of locomotion in hominoids and early hominins. We assessed (1) the extent to which great apes use diagonal sequence, diagonal couplet gaits, like other primates, (2) the extent to which gait and posture vary across great apes, and (3) the role of body mass and limb proportions on ape quadrupedal kinematics.<h4>Methods</h4>High-speed digital video of zoo-housed bonobos (Pan paniscus, N = 8), chimpanzees (Pan troglodytes, N = 13), lowland gorillas (Gorilla gorilla, N = 13), and orangutans (Pongo spp. N = 6) walking over-ground at self-selected speeds were used to determine the timing of limb touch-down, take-off, and to measure joint and segment angles at touch-down, midstance, and take-off.<h4>Results</h4>The great apes in our study showed broad kinematic and spatiotemporal similarity in quadrupedal walking. Size-adjusted walking speed was the strongest predictor of gait variables. Body mass had a negligible effect on variation in joint and segment angles, but stride frequency did trend higher among larger apes in analyses including size-adjusted speed. In contrast to most other primates, great apes did not favor diagonal sequence footfall patterns, but exhibited variable gait patterns that frequently shifted between diagonal and lateral sequences.<h4>Conclusion</h4>Similarities in the terrestrial walking kinematics of extant great apes likely reflect their similar post-cranial anatomy and proportions. Our results suggest that the walking kinematics of orthograde, suspensory Miocene ape species were likely similar to living great apes, and highlight the utility of videographic and behavioral data in interpreting primate skeletal morphology.}, Doi = {10.1002/ajpa.23397}, Key = {fds337754} } @article{fds337755, Author = {Urlacher, SS and Ellison, PT and Sugiyama, LS and Pontzer, H and Eick, G and Liebert, MA and Cepon-Robins, TJ and Gildner, TE and Snodgrass, JJ}, Title = {Tradeoffs between immune function and childhood growth among Amazonian forager-horticulturalists.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {115}, Number = {17}, Pages = {E3914-E3921}, Year = {2018}, Month = {April}, url = {http://dx.doi.org/10.1073/pnas.1717522115}, Abstract = {Immune function is an energetically costly physiological activity that potentially diverts calories away from less immediately essential life tasks. Among developing organisms, the allocation of energy toward immune function may lead to tradeoffs with physical growth, particularly in high-pathogen, low-resource environments. The present study tests this hypothesis across diverse timeframes, branches of immunity, and conditions of energy availability among humans. Using a prospective mixed-longitudinal design, we collected anthropometric and blood immune biomarker data from 261 Amazonian forager-horticulturalist Shuar children (age 4-11 y old). This strategy provided baseline measures of participant stature, s.c. body fat, and humoral and cell-mediated immune activity as well as subsample longitudinal measures of linear growth (1 wk, 3 mo, 20 mo) and acute inflammation. Multilevel analyses demonstrate consistent negative effects of immune function on growth, with children experiencing up to 49% growth reduction during periods of mildly elevated immune activity. The direct energetic nature of these relationships is indicated by (<i>i</i>) the manifestation of biomarker-specific negative immune effects only when examining growth over timeframes capturing active competition for energetic resources, (<i>ii</i>) the exaggerated impact of particularly costly inflammation on growth, and (<i>iii</i>) the ability of children with greater levels of body fat (i.e., energy reserves) to completely avoid the growth-inhibiting effects of acute inflammation. These findings provide evidence for immunologically and temporally diverse body fat-dependent tradeoffs between immune function and growth during childhood. We discuss the implications of this work for understanding human developmental energetics and the biological mechanisms regulating variation in human ontogeny, life history, and health.}, Doi = {10.1073/pnas.1717522115}, Key = {fds337755} } @article{fds337756, Author = {Kozma, EE and Webb, NM and Harcourt-Smith, WEH and Raichlen, DA and D'Août, K and Brown, MH and Finestone, EM and Ross, SR and Aerts, P and Pontzer, H}, Title = {Hip extensor mechanics and the evolution of walking and climbing capabilities in humans, apes, and fossil hominins.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {115}, Number = {16}, Pages = {4134-4139}, Year = {2018}, Month = {April}, url = {http://dx.doi.org/10.1073/pnas.1715120115}, Abstract = {The evolutionary emergence of humans' remarkably economical walking gait remains a focus of research and debate, but experimentally validated approaches linking locomotor capability to postcranial anatomy are limited. In this study, we integrated 3D morphometrics of hominoid pelvic shape with experimental measurements of hip kinematics and kinetics during walking and climbing, hamstring activity, and passive range of hip extension in humans, apes, and other primates to assess arboreal-terrestrial trade-offs in ischium morphology among living taxa. We show that hamstring-powered hip extension during habitual walking and climbing in living apes and humans is strongly predicted, and likely constrained, by the relative length and orientation of the ischium. Ape pelves permit greater extensor moments at the hip, enhancing climbing capability, but limit their range of hip extension, resulting in a crouched gait. Human pelves reduce hip extensor moments but permit a greater degree of hip extension, which greatly improves walking economy (i.e., distance traveled/energy consumed). Applying these results to fossil pelves suggests that early hominins differed from both humans and extant apes in having an economical walking gait without sacrificing climbing capability. <i>Ardipithecus</i> was capable of nearly human-like hip extension during bipedal walking, but retained the capacity for powerful, ape-like hip extension during vertical climbing. Hip extension capability was essentially human-like in <i>Australopithecus afarensis</i> and <i>Australopithecus africanus</i>, suggesting an economical walking gait but reduced mechanical advantage for powered hip extension during climbing.}, Doi = {10.1073/pnas.1715120115}, Key = {fds337756} } @article{fds337762, Author = {Pontzer, H and Raichlen, DA and Basdeo, T and Harris, JA and Mabulla, AZP and Wood, BM}, Title = {Mechanics of archery among Hadza hunter-gatherers}, Journal = {Journal of Archaeological Science: Reports}, Volume = {16}, Pages = {57-64}, Publisher = {Elsevier BV}, Year = {2017}, Month = {December}, url = {http://dx.doi.org/10.1016/j.jasrep.2017.09.025}, Abstract = {The development of the bow and arrow was an important milestone in the evolution of foraging technology. Experimental approaches to interpreting lithics and other archeological evidence for early archery have led to important insights into their manufacture and use, but these studies are limited by a lack of data on the mechanics of traditional archery among living hunter-gatherers. Here, we investigated archery mechanics among the Hadza, a population of traditional hunter-gatherers living in Tanzania, who build and use their own bows and arrows to hunt wild game for food. Ten Hadza men participated in an archery competition with targets set at 15, 30, and 50 m, similar to the range of target distances during hunting. We used a spring scale to calibrate the draw force for each bow, and a high-speed digital video to record shooting mechanics and arrow velocity for each shot. Arrow velocity (45.1 ± 7.0 m/s− 1) and estimated kinetic energy (36.9 ± 13.4 J) were greater than typically employed in experimental archeology studies. Draw forces (311 ± 98 N) were also greater, equivalent to ~ 70% of men's body weight. Approximately 70% of the strain energy from the drawn bow was converted to arrow kinetic energy upon release, similar to published efficiencies for modern recurve bows. Arrow kinetic energy and draw force were similar for 15 m and 30 m targets, but increased marginally for the 50 m target, suggesting that Hadza men adjust arrow trajectory for targets at short and middle distances, but may increase draw force and hence arrow energy for distant targets.}, Doi = {10.1016/j.jasrep.2017.09.025}, Key = {fds337762} } @article{fds337763, Author = {Pontzer, H}, Title = {DEMOGRAPHY AND EVOLUTIONARY ECOLOGY OF HADZA HUNTER‐GATHERERS By NicholasBlurton Jones508 pp. (2016). Cambridge: Cambridge University Press. $130.00 (paperback)}, Journal = {American Journal of Human Biology}, Volume = {29}, Number = {6}, Pages = {e23053-e23053}, Publisher = {Wiley}, Year = {2017}, Month = {November}, url = {http://dx.doi.org/10.1002/ajhb.23053}, Doi = {10.1002/ajhb.23053}, Key = {fds337763} } @article{fds337764, Author = {Horiuchi, M and Fukuoka, Y and Handa, Y and Abe, D and Pontzer, H}, Title = {Measuring the Energy of Ventilation and Circulation during Human Walking using Induced Hypoxia.}, Journal = {Scientific reports}, Volume = {7}, Number = {1}, Pages = {4938}, Year = {2017}, Month = {July}, url = {http://dx.doi.org/10.1038/s41598-017-05068-8}, Abstract = {Energy expenditure (EE) during walking includes energy costs to move and support the body and for respiration and circulation. We measured EE during walking under three different oxygen concentrations. Eleven healthy, young, male lowlanders walked on a treadmill at seven gait speeds (0.67-1.83 m s<sup>-1</sup>) on a level gradient under normobaric normoxia (room air, 21% O<sub>2</sub>), moderate hypoxia (15% O<sub>2</sub>), and severe hypoxia (11% O<sub>2</sub>). By comparing the hypoxia-induced elevation in heart rate (HR [bpm]), ventilation (V<sub>E</sub> [L min<sup>-1</sup>]) with the change in energy expenditure (EE [W]) at each speed, we were able to determine circulatory and respiratory costs. In a multivariate model combining HR and V<sub>E</sub>, respiratory costs were 0.44 ± 0.15 W per each L min<sup>-1</sup> increase in V<sub>E</sub>, and circulatory costs were 0.24 ± 0.05 W per each bpm increase in HR (model adjusted r<sup>2</sup> = 0.97, p < 0.001). These V<sub>E</sub> costs were substantially lower than previous studies that ignored the contribution of HR to cardiopulmonary work. Estimated HR costs were consistent with, although somewhat higher than, measures derived from catheterization studies. Cardiopulmonary costs accounted for 23% of resting EE, but less than 5% of net walking costs (i.e., with resting EE subtracted).}, Doi = {10.1038/s41598-017-05068-8}, Key = {fds337764} } @article{fds337765, Author = {Pontzer, H}, Title = {Economy and Endurance in Human Evolution.}, Journal = {Current biology : CB}, Volume = {27}, Number = {12}, Pages = {R613-R621}, Year = {2017}, Month = {June}, url = {http://dx.doi.org/10.1016/j.cub.2017.05.031}, Abstract = {The evolutionary pressures shaping humans' unique bipedal locomotion have been a focus of research since Darwin, but the origins of humans' economical walking gait and endurance running capabilities remain unclear. Here, I review the anatomical and physiological determinants of locomotor economy (e.g., limb length and posture) and endurance (e.g., muscle volume and fiber type) and investigate their development in the hominin fossil record. The earliest hominins were bipedal but retained ape-like features in the hind limb that would have limited their walking economy compared to living humans. Moreover, the evolution of bipedalism and the loss of the forelimbs in weight support and propulsion would have reduced locomotor endurance in the earliest hominins and likely restricted ranging. Australopithecus evinced longer hind limbs, extended limb posture, and a stiff midfoot, suggesting improved, human-like economy, but were likely still limited in their endurance compared to modern humans. The appearance of skeletal traits related to endurance (e.g., larger limb joints, spring-like plantar arch) in Homo was somewhat mosaic, with the full endurance suite apparent only ∼1 million years ago. The development of endurance capabilities in Homo appears to parallel the evolutionary increase in brain size, cognitive sophistication, and metabolic rate.}, Doi = {10.1016/j.cub.2017.05.031}, Key = {fds337765} } @article{fds337766, Author = {Edwards, W and Lonsdorf, EV and Pontzer, H}, Title = {Total energy expenditure in captive capuchins (Sapajus apella).}, Journal = {American journal of primatology}, Volume = {79}, Number = {5}, Year = {2017}, Month = {May}, url = {http://dx.doi.org/10.1002/ajp.22638}, Abstract = {Primates have markedly lower total energy expenditure (TEE; kcal/day) than other placental mammals, expending approximately 50% less energy for their mass than non-primate eutherians. However, little is known regarding interspecific variation of energy expenditure within platyrrhine primates. We investigated TEE in captive tufted capuchins (Sapajus apella, n = 8, ages 7-36), a frugivorous platyrrhine, to compare TEE with other placental mammals and primates. We tested the hypothesis that large-brained capuchins would exhibit greater TEE than other platyrrhines that are less encephalized. We used the doubly labeled water (DLW) method to measure TEE over 7-11 days, during which physical activity data were recorded via focal observation. TEE was strongly correlated with fat free mass, but sex, age, and rates of walking and climbing were not correlated with variation in TEE in multivariate analyses controlling for fat free mass. We found evidence that daily physical activity was negatively correlated with body fat percentage. Capuchin TEE was similar (P = 0.67) to other, less encephalized platyrrhines (Callithrix and Alouatta) and 54% lower than other placental mammals, in analyses controlling for body mass. These results suggest that brain size and physical activity do not necessarily influence variation in daily energy expenditure across primate species.}, Doi = {10.1002/ajp.22638}, Key = {fds337766} } @article{fds337778, Author = {Raichlen, DA and Pontzer, H and Harris, JA and Mabulla, AZP and Marlowe, FW and Josh Snodgrass and J and Eick, G and Colette Berbesque and J and Sancilio, A and Wood, BM}, Title = {Physical activity patterns and biomarkers of cardiovascular disease risk in hunter-gatherers.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {29}, Number = {2}, Year = {2017}, Month = {March}, url = {http://dx.doi.org/10.1002/ajhb.22919}, Abstract = {<h4>Objectives</h4>Time spent in moderate-to-vigorous physical activity (MVPA) is a strong predictor of cardiovascular health, yet few humans living in industrialized societies meet current recommendations (150 min/week). Researchers have long suggested that human physiological requirements for aerobic exercise reflect an evolutionary shift to a hunting and gathering foraging strategy, and a recent transition to more sedentary lifestyles likely represents a mismatch with our past in terms of physical activity. The goal of this study is to explore this mismatch by characterizing MVPA and cardiovascular health in the Hadza, a modern hunting and gathering population living in Northern Tanzania.<h4>Methods</h4>We measured MVPA using continuous heart rate monitoring in 46 participants recruited from two Hadza camps. As part of a larger survey of health in the Hadza, we measured blood pressure (n = 198) and biomarkers of cardiovascular health (n = 23) including C-reactive protein, cholesterol (Total, HDL, and LDL), and triglycerides.<h4>Results</h4>We show that Hadza participants spend large amounts of time in MVPA (134.92 ± 8.6 min/day), and maintain these activity levels across the lifespan. In fact, the Hadza engage in over 14 times as much MVPA as subjects participating in large epidemiological studies in the United States. We found no evidence of risk factors for cardiovascular disease in this population (low prevalence of hypertension across the lifespan, optimal levels for biomarkers of cardiovascular health).<h4>Conclusions</h4>Our results provide evidence that the hunting and gathering foraging strategy involves high levels of MVPA, supporting the evolutionary medicine model for the relationship between MVPA and cardiovascular health.}, Doi = {10.1002/ajhb.22919}, Key = {fds337778} } @article{fds337779, Author = {Pontzer, H}, Title = {The crown joules: energetics, ecology, and evolution in humans and other primates.}, Journal = {Evolutionary anthropology}, Volume = {26}, Number = {1}, Pages = {12-24}, Year = {2017}, Month = {January}, url = {http://dx.doi.org/10.1002/evan.21513}, Abstract = {Biological diversity is metabolic diversity: Differences in anatomy, physiology, life history, and activity reflect differences in energy allocation and expenditure among traits and tasks. Traditional frameworks in primatology, human ecology, public health, and paleoanthropology view daily energy expenditure as being more variable within than between species, changing with activity level but essentially fixed for a given body size. Growing evidence turns this view on its head. Total energy expenditure (kcal/d), varies relatively little within species, despite variation in physical activity; it varies considerably among species even after controlling for the effect of body size. Embracing this emerging paradigm requires rethinking potential trade-offs in energy allocation within and between species, assessing evidence of metabolic acceleration within lineages, and abandoning activity-based estimates of total energy expenditure. Difficult and exciting work lies ahead in the effort to untangle the ecological and evolutionary pressures shaping primate metabolic diversity.}, Doi = {10.1002/evan.21513}, Key = {fds337779} } @article{fds337780, Author = {Sparrow, LM and Pellatt, E and Yu, SS and Raichlen, DA and Pontzer, H and Rolian, C}, Title = {Gait changes in a line of mice artificially selected for longer limbs.}, Journal = {PeerJ}, Volume = {5}, Pages = {e3008}, Year = {2017}, Month = {January}, url = {http://dx.doi.org/10.7717/peerj.3008}, Abstract = {In legged terrestrial locomotion, the duration of stance phase, i.e., when limbs are in contact with the substrate, is positively correlated with limb length, and negatively correlated with the metabolic cost of transport. These relationships are well documented at the interspecific level, across a broad range of body sizes and travel speeds. However, such relationships are harder to evaluate within species (i.e., where natural selection operates), largely for practical reasons, including low population variance in limb length, and the presence of confounding factors such as body mass, or training. Here, we compared spatiotemporal kinematics of gait in Longshanks, a long-legged mouse line created through artificial selection, and in random-bred, mass-matched Control mice raised under identical conditions. We used a gait treadmill to test the hypothesis that Longshanks have longer stance phases and stride lengths, and decreased stride frequencies in both fore- and hind limbs, compared with Controls. Our results indicate that gait differs significantly between the two groups. Specifically, and as hypothesized, stance duration and stride length are 8-10% greater in Longshanks, while stride frequency is 8% lower than in Controls. However, there was no difference in the touch-down timing and sequence of the paws between the two lines. Taken together, these data suggest that, for a given speed, Longshanks mice take significantly fewer, longer steps to cover the same distance or running time compared to Controls, with important implications for other measures of variation among individuals in whole-organism performance, such as the metabolic cost of transport.}, Doi = {10.7717/peerj.3008}, Key = {fds337780} } @article{fds337781, Author = {Hora, M and Soumar, L and Pontzer, H and Sládek, V}, Title = {Body size and lower limb posture during walking in humans.}, Journal = {PloS one}, Volume = {12}, Number = {2}, Pages = {e0172112}, Year = {2017}, Month = {January}, url = {http://dx.doi.org/10.1371/journal.pone.0172112}, Abstract = {We test whether locomotor posture is associated with body mass and lower limb length in humans and explore how body size and posture affect net joint moments during walking. We acquired gait data for 24 females and 25 males using a three-dimensional motion capture system and pressure-measuring insoles. We employed the general linear model and commonality analysis to assess the independent effect of body mass and lower limb length on flexion angles at the hip, knee, and ankle while controlling for sex and velocity. In addition, we used inverse dynamics to model the effect of size and posture on net joint moments. At early stance, body mass has a negative effect on knee flexion (p < 0.01), whereas lower limb length has a negative effect on hip flexion (p < 0.05). Body mass uniquely explains 15.8% of the variance in knee flexion, whereas lower limb length uniquely explains 5.4% of the variance in hip flexion. Both of the detected relationships between body size and posture are consistent with the moment moderating postural adjustments predicted by our model. At late stance, no significant relationship between body size and posture was detected. Humans of greater body size reduce the flexion of the hip and knee at early stance, which results in the moderation of net moments at these joints.}, Doi = {10.1371/journal.pone.0172112}, Key = {fds337781} } @article{fds337782, Author = {Pontzer, H}, Title = {The Exercise Paradox.}, Journal = {Scientific American}, Volume = {316}, Number = {2}, Pages = {26-31}, Year = {2017}, Month = {January}, url = {http://dx.doi.org/10.1038/scientificamerican0217-26}, Doi = {10.1038/scientificamerican0217-26}, Key = {fds337782} } @article{fds337783, Author = {Gurven, MD and Trumble, BC and Stieglitz, J and Yetish, G and Cummings, D and Blackwell, AD and Beheim, B and Kaplan, HS and Pontzer, H}, Title = {High resting metabolic rate among Amazonian forager-horticulturalists experiencing high pathogen burden.}, Journal = {American journal of physical anthropology}, Volume = {161}, Number = {3}, Pages = {414-425}, Year = {2016}, Month = {November}, url = {http://dx.doi.org/10.1002/ajpa.23040}, Abstract = {<h4>Objectives</h4>Resting metabolic rate (RMR) reflects energetic costs of homeostasis and accounts for 60 to 75% of total energy expenditure (TEE). Lean mass and physical activity account for much RMR variability, but the impact of prolonged immune activation from infection on human RMR is unclear in naturalistic settings. We evaluate the effects of infection on mass-corrected RMR among Bolivian forager-horticulturalists, and assess whether RMR declines more slowly with age than in hygienic sedentary populations, as might be expected if older adults experience high pathogen burden.<h4>Materials and methods</h4>RMR was measured by indirect calorimetry (Fitmate MED, Cosmed) in 1,300 adults aged 20 to 90 and TEE was measured using doubly labeled water (n = 40). Immune biomarkers, clinical diagnoses, and anthropometrics were collected by the Tsimane Health and Life History Project.<h4>Results</h4>Tsimane have higher RMR and TEE than people in sedentary industrialized populations. Tsimane RMR is 18 to 47% (women) and 22 to 40% (men) higher than expected using six standard prediction equations. Tsimane mass-corrected TEE is similarly elevated compared to Westerners. Elevated leukocytes and helminths are associated with excess RMR in multivariate regressions, and jointly result in a predicted excess RMR of 10 to 15%. After age 40, RMR declines by 69 kcal/decade (p < .0001). Controlling for lean mass and height accounts for 71% of age-related RMR decline, and adding indicators of infection minimally affects the age slope. The residual level of age-related decline from age 40 is 1.2% per decade.<h4>Conclusion</h4>High pathogen burden may lead to higher metabolic costs, which may be offset by smaller body mass or other energy-sparing mechanisms.}, Doi = {10.1002/ajpa.23040}, Key = {fds337783} } @article{fds337784, Author = {Pontzer, H}, Title = {Behavior: Knowing When to Walk Away, Knowing When to Run.}, Journal = {Current biology : CB}, Volume = {26}, Number = {15}, Pages = {R717-R718}, Year = {2016}, Month = {August}, url = {http://dx.doi.org/10.1016/j.cub.2016.06.048}, Abstract = {A new model has been proposed indicating that humans and other animals weigh the metabolic cost of pursuit in deciding how fast to move toward a given reward, providing a powerful framework for understanding behavior.}, Doi = {10.1016/j.cub.2016.06.048}, Key = {fds337784} } @article{fds337785, Author = {Pontzer, H and Brown, MH and Raichlen, DA and Dunsworth, H and Hare, B and Walker, K and Luke, A and Dugas, LR and Durazo-Arvizu, R and Schoeller, D and Plange-Rhule, J and Bovet, P and Forrester, TE and Lambert, EV and Thompson, ME and Shumaker, RW and Ross, SR}, Title = {Metabolic acceleration and the evolution of human brain size and life history.}, Journal = {Nature}, Volume = {533}, Number = {7603}, Pages = {390-392}, Year = {2016}, Month = {May}, url = {http://dx.doi.org/10.1038/nature17654}, Abstract = {Humans are distinguished from the other living apes in having larger brains and an unusual life history that combines high reproductive output with slow childhood growth and exceptional longevity. This suite of derived traits suggests major changes in energy expenditure and allocation in the human lineage, but direct measures of human and ape metabolism are needed to compare evolved energy strategies among hominoids. Here we used doubly labelled water measurements of total energy expenditure (TEE; kcal day(-1)) in humans, chimpanzees, bonobos, gorillas and orangutans to test the hypothesis that the human lineage has experienced an acceleration in metabolic rate, providing energy for larger brains and faster reproduction without sacrificing maintenance and longevity. In multivariate regressions including body size and physical activity, human TEE exceeded that of chimpanzees and bonobos, gorillas and orangutans by approximately 400, 635 and 820 kcal day(-1), respectively, readily accommodating the cost of humans' greater brain size and reproductive output. Much of the increase in TEE is attributable to humans' greater basal metabolic rate (kcal day(-1)), indicating increased organ metabolic activity. Humans also had the greatest body fat percentage. An increased metabolic rate, along with changes in energy allocation, was crucial in the evolution of human brain size and life history.}, Doi = {10.1038/nature17654}, Key = {fds337785} } @article{fds337786, Author = {Yetish, G and Kaplan, H and Gurven, M and Wood, B and Pontzer, H and Manger, PR and Wilson, C and McGregor, R and Siegel, JM}, Title = {Response to de la Iglesia et al.}, Journal = {Current biology : CB}, Volume = {26}, Number = {7}, Pages = {R273-R274}, Year = {2016}, Month = {April}, url = {http://dx.doi.org/10.1016/j.cub.2016.02.057}, Abstract = {We wish to respond to the commentary of de la Iglesia et al. [1]. Studies comparing sleep in different communities have different goals. One frequent goal has been to determine how sleep is affected by manipulating specific 'modern' conditions. Many studies have investigated the effect of artificial light and electronic entertainment. Such studies have clearly shown that light, particularly blue light, delays sleep onset [2]. Studying the effect of artificial light on sleep was not a goal of our study.}, Doi = {10.1016/j.cub.2016.02.057}, Key = {fds337786} } @article{fds337787, Author = {Laird, MF and Vogel, ER and Pontzer, H}, Title = {Chewing efficiency and occlusal functional morphology in modern humans.}, Journal = {Journal of human evolution}, Volume = {93}, Pages = {1-11}, Year = {2016}, Month = {April}, url = {http://dx.doi.org/10.1016/j.jhevol.2015.11.005}, Abstract = {The reduction of occlusal dimensions in early Homo is often proposed to be a functional adaptation to diet. With their smaller occlusal surfaces, species of early Homo are suggested to have reduced food-processing abilities, particularly for foods with high material properties (e.g., increased toughness). Here, we employ chewing efficiency as a measure of masticatory performance to test the relationships between masticatory function and food properties. We predicted that humans are more efficient when processing foods of lower toughness and Young's modulus values, and that subjects with larger occlusal surfaces will be less efficient when processing foods with higher toughness and Young's modulus, as the greater area spreads out the overall bite force applied to food particles. Chewing efficiency was measured in 26 adults using high-speed motion capture and surface electromyography. The dentition of each subject was cast and the occlusal surface was quantified using dental topographic analysis. Toughness and displacement-limited index were negatively correlated with chewing efficiency, but Young's modulus was not. Increased occlusal two-dimensional area and surface area were positively correlated with chewing efficiency for all foods. Thus, larger occlusal surface areas were more efficient when processing foods of greater toughness. These results suggest that the reduction in occlusal area in early Homo was associated with a reduction in chewing efficiency, particularly for foods with greater toughness. Further, the larger occlusal surfaces of earlier hominins such as Australopithecus would have likely increased chewing efficiency and increased the probability of fracture when processing tough foods.}, Doi = {10.1016/j.jhevol.2015.11.005}, Key = {fds337787} } @article{fds337797, Author = {Pontzer, H and Durazo-Arvizu, R and Dugas, LR and Plange-Rhule, J and Bovet, P and Forrester, TE and Lambert, EV and Cooper, RS and Schoeller, DA and Luke, A}, Title = {Constrained Total Energy Expenditure and Metabolic Adaptation to Physical Activity in Adult Humans.}, Journal = {Current biology : CB}, Volume = {26}, Number = {3}, Pages = {410-417}, Year = {2016}, Month = {February}, url = {http://dx.doi.org/10.1016/j.cub.2015.12.046}, Abstract = {Current obesity prevention strategies recommend increasing daily physical activity, assuming that increased activity will lead to corresponding increases in total energy expenditure and prevent or reverse energy imbalance and weight gain [1-3]. Such Additive total energy expenditure models are supported by exercise intervention and accelerometry studies reporting positive correlations between physical activity and total energy expenditure [4] but are challenged by ecological studies in humans and other species showing that more active populations do not have higher total energy expenditure [5-8]. Here we tested a Constrained total energy expenditure model, in which total energy expenditure increases with physical activity at low activity levels but plateaus at higher activity levels as the body adapts to maintain total energy expenditure within a narrow range. We compared total energy expenditure, measured using doubly labeled water, against physical activity, measured using accelerometry, for a large (n = 332) sample of adults living in five populations [9]. After adjusting for body size and composition, total energy expenditure was positively correlated with physical activity, but the relationship was markedly stronger over the lower range of physical activity. For subjects in the upper range of physical activity, total energy expenditure plateaued, supporting a Constrained total energy expenditure model. Body fat percentage and activity intensity appear to modulate the metabolic response to physical activity. Models of energy balance employed in public health [1-3] should be revised to better reflect the constrained nature of total energy expenditure and the complex effects of physical activity on metabolic physiology.}, Doi = {10.1016/j.cub.2015.12.046}, Key = {fds337797} } @article{fds337798, Author = {Pontzer, H}, Title = {A unified theory for the energy cost of legged locomotion.}, Journal = {Biology letters}, Volume = {12}, Number = {2}, Pages = {20150935}, Year = {2016}, Month = {February}, url = {http://dx.doi.org/10.1098/rsbl.2015.0935}, Abstract = {Small animals are remarkably efficient climbers but comparatively poor runners, a well-established phenomenon in locomotor energetics that drives size-related differences in locomotor ecology yet remains poorly understood. Here, I derive the energy cost of legged locomotion from two complementary components of muscle metabolism, Activation-Relaxation and Cross-bridge cycling. A mathematical model incorporating these costs explains observed patterns of locomotor cost both within and between species, across a broad range of animals (insects to ungulates), for a wide range of substrate slopes including level running and vertical climbing. This ARC model unifies work- and force-based models for locomotor cost and integrates whole-organism locomotor cost with cellular muscle physiology, creating a predictive framework for investigating evolutionary and ecological pressures shaping limb design and ranging behaviour.}, Doi = {10.1098/rsbl.2015.0935}, Key = {fds337798} } @article{fds337799, Author = {Yetish, G and Kaplan, H and Gurven, M and Wood, B and Pontzer, H and Manger, PR and Wilson, C and McGregor, R and Siegel, JM}, Title = {Natural sleep and its seasonal variations in three pre-industrial societies.}, Journal = {Current biology : CB}, Volume = {25}, Number = {21}, Pages = {2862-2868}, Year = {2015}, Month = {November}, url = {http://dx.doi.org/10.1016/j.cub.2015.09.046}, Abstract = {How did humans sleep before the modern era? Because the tools to measure sleep under natural conditions were developed long after the invention of the electric devices suspected of delaying and reducing sleep, we investigated sleep in three preindustrial societies [1-3]. We find that all three show similar sleep organization, suggesting that they express core human sleep patterns, most likely characteristic of pre-modern era Homo sapiens. Sleep periods, the times from onset to offset, averaged 6.9-8.5 hr, with sleep durations of 5.7-7.1 hr, amounts near the low end of those industrial societies [4-7]. There was a difference of nearly 1 hr between summer and winter sleep. Daily variation in sleep duration was strongly linked to time of onset, rather than offset. None of these groups began sleep near sunset, onset occurring, on average, 3.3 hr after sunset. Awakening was usually before sunrise. The sleep period consistently occurred during the nighttime period of falling environmental temperature, was not interrupted by extended periods of waking, and terminated, with vasoconstriction, near the nadir of daily ambient temperature. The daily cycle of temperature change, largely eliminated from modern sleep environments, may be a potent natural regulator of sleep. Light exposure was maximal in the morning and greatly decreased at noon, indicating that all three groups seek shade at midday and that light activation of the suprachiasmatic nucleus is maximal in the morning. Napping occurred on <7% of days in winter and <22% of days in summer. Mimicking aspects of the natural environment might be effective in treating certain modern sleep disorders.}, Doi = {10.1016/j.cub.2015.09.046}, Key = {fds337799} } @article{fds337800, Author = {Pontzer, H}, Title = {Energy Expenditure in Humans and Other Primates: A New Synthesis}, Journal = {Annual Review of Anthropology}, Volume = {44}, Number = {1}, Pages = {169-187}, Publisher = {ANNUAL REVIEWS}, Year = {2015}, Month = {October}, url = {http://dx.doi.org/10.1146/annurev-anthro-102214-013925}, Abstract = {This review examines the proximate, ecological, and evolutionary determinants of energy expenditure in humans and primates, with an emphasis on empirical measurements of total energy expenditure (TEE). Body size is the main proximate determinant of TEE, both within and between species; physical activity, genetic variation, and endocrine regulation explain substantially less of the variation in TEE. Basal metabolism is the single largest component of TEE, far exceeding the cost of physical activity, digestion, growth and reproduction, and thermoregulation in most instances. Notably, differences in physical activity do not generally result in corresponding differences in TEE, undermining the utility of activity-based factorial estimates of TEE. Instead, empirical measurements of energy expenditure in humans and other primates suggest that the body adapts dynamically to long-term changes in physical activity, maintaining TEE within an evolved, and relatively narrow, physiological range. ©}, Doi = {10.1146/annurev-anthro-102214-013925}, Key = {fds337800} } @article{fds337801, Author = {Pontzer, H and Raichlen, DA and Wood, BM and Emery Thompson and M and Racette, SB and Mabulla, AZP and Marlowe, FW}, Title = {Energy expenditure and activity among Hadza hunter-gatherers.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {27}, Number = {5}, Pages = {628-637}, Year = {2015}, Month = {September}, url = {http://dx.doi.org/10.1002/ajhb.22711}, Abstract = {<h4>Objectives</h4>Studies of total energy expenditure, (TEE; kcal/day) among traditional populations have challenged current models relating habitual physical activity to daily energy requirements. Here, we examine the relationship between physical activity and TEE among traditional Hadza hunter-gatherers living in northern Tanzania.<h4>Methods</h4>Hadza adults were studied at two camps, with minimal intervention so as to monitor energy expenditure and activity during normal daily life. We measured daily walking distance and walking speed using wearable GPS units for 41 adults. For a subset of 30 adults, we measured TEE using doubly labeled water, three indices of work load (foraging return rate, maternal status, and number of dependent children), and urinary biomarkers of metabolic activity and stress (8-hydroxydeoxyguanosine, cortisol, and testosterone).<h4>Results</h4>Fat-free mass was the single strongest predictor of TEE among Hadza adults (r(2) = 0.66, P < 0.001). Hadza men used greater daily walking distances and faster walking speeds compared with that of Hadza women, but neither sex nor any measure of physical activity or work load were correlated with TEE in analyses controlling for fat-free mass. Compared with developed, industrial populations, Hadza adults had similar TEE but elevated levels of metabolic stress as measured by 8-hydroxydeoxyguanosine.<h4>Conclusion</h4>Our results indicate that daily physical activity may not predict TEE within traditional hunter-gatherer populations like the Hadza. Instead, adults with high levels of habitual physical activity may adapt by reducing energy allocation to other physiological activity.}, Doi = {10.1002/ajhb.22711}, Key = {fds337801} } @article{fds337802, Author = {Pontzer, H}, Title = {Constrained Total Energy Expenditure and the Evolutionary Biology of Energy Balance.}, Journal = {Exercise and sport sciences reviews}, Volume = {43}, Number = {3}, Pages = {110-116}, Year = {2015}, Month = {July}, url = {http://dx.doi.org/10.1249/jes.0000000000000048}, Abstract = {The human body adapts dynamically to maintain total energy expenditure (TEE) within a narrow physiological range. Rather than increasing with physical activity in a dose-dependent manner, experimental and ecological evidence suggests the hypothesis that TEE is a relatively constrained product of our evolved physiology.}, Doi = {10.1249/jes.0000000000000048}, Key = {fds337802} } @article{fds337808, Author = {Warrener, AG and Lewton, KL and Pontzer, H and Lieberman, DE}, Title = {A wider pelvis does not increase locomotor cost in humans, with implications for the evolution of childbirth.}, Journal = {PloS one}, Volume = {10}, Number = {3}, Pages = {e0118903}, Year = {2015}, Month = {January}, url = {http://dx.doi.org/10.1371/journal.pone.0118903}, Abstract = {The shape of the human female pelvis is thought to reflect an evolutionary trade-off between two competing demands: a pelvis wide enough to permit the birth of large-brained infants, and narrow enough for efficient bipedal locomotion. This trade-off, known as the obstetrical dilemma, is invoked to explain the relative difficulty of human childbirth and differences in locomotor performance between men and women. The basis for the obstetrical dilemma is a standard static biomechanical model that predicts wider pelves in females increase the metabolic cost of locomotion by decreasing the effective mechanical advantage of the hip abductor muscles for pelvic stabilization during the single-leg support phase of walking and running, requiring these muscles to produce more force. Here we experimentally test this model against a more accurate dynamic model of hip abductor mechanics in men and women. The results show that pelvic width does not predict hip abductor mechanics or locomotor cost in either women or men, and that women and men are equally efficient at both walking and running. Since a wider birth canal does not increase a woman's locomotor cost, and because selection for successful birthing must be strong, other factors affecting maternal pelvic and fetal size should be investigated in order to help explain the prevalence of birth complications caused by a neonate too large to fit through the birth canal.}, Doi = {10.1371/journal.pone.0118903}, Key = {fds337808} } @article{fds337809, Author = {Wood, BM and Pontzer, H and Raichlen, DA and Marlowe, FW}, Title = {Mutualism and manipulation in Hadza-honeyguide interactions}, Journal = {Evolution and Human Behavior}, Volume = {35}, Number = {6}, Pages = {540-546}, Publisher = {Elsevier BV}, Year = {2014}, Month = {November}, url = {http://dx.doi.org/10.1016/j.evolhumbehav.2014.07.007}, Abstract = {We investigated the ecology and evolution of interspecific cooperation between the Greater Honeyguide bird, Indicator indicator, and human hunter-gatherers, the Hadza of northern Tanzania. We found that honeyguides increased the Hadza's rate of finding bee nests by 560%, and that the birds led men to significantly higher yielding nests than those found without honeyguides. We estimate that 8-10% of the Hadza's total diet was acquired with the help of honeyguides. Contrary to most depictions of the human-honeyguide relationship, the Hadza did not actively repay honeyguides, but instead, hid, buried, and burned honeycomb, with the intent of keeping the bird hungry and thus more likely to guide again. Such manipulative behavior attests to the importance of social intelligence in hunter-gatherer foraging strategies. We present an evolutionary model for human-honeyguide interactions guided by the behavioral ecology of bees, non-human primates, and hunter-gatherers.}, Doi = {10.1016/j.evolhumbehav.2014.07.007}, Key = {fds337809} } @article{fds337811, Author = {Raubenheimer, D and Rothman, JM and Pontzer, H and Simpson, SJ}, Title = {Macronutrient contributions of insects to the diets of hunter-gatherers: a geometric analysis.}, Journal = {Journal of human evolution}, Volume = {71}, Pages = {70-76}, Year = {2014}, Month = {June}, url = {http://dx.doi.org/10.1016/j.jhevol.2014.02.007}, Abstract = {We present a geometric model for examining the macronutrient contributions of insects in the diets of pre-agricultural humans, and relate the findings to some contemporary societies that regularly eat insects. The model integrates published data on the macronutrient composition of insects and other foods in the diets of humans, recommended human macronutrient intakes, and estimated macronutrient intakes to examine the assumption that insects provided to pre-agricultural humans an invertebrate equivalent of vertebrate-derived meats, serving primarily as a source of protein. Our analysis suggests that insects vary more widely in their macronutrient content than is likely to be the case for most wild vertebrate meats, spanning a broad range of protein, fat and carbohydrate concentrations. Potentially, therefore, in terms of their proportional macronutrient composition, insects could serve as equivalents not only of wild meat, but of a range of other foods including some shellfish, nuts, pulses, vegetables and even fruits. Furthermore, humans might systematically manipulate the composition of edible insects to meet specific needs through pre-ingestive processing, such as cooking and selective removal of body parts. We present data suggesting that in modern societies for which protein is the more limiting macronutrient, pre-ingestive processing of edible insects might serve to concentrate protein. It is likely, however, that the dietary significance of insects was different for Paleolithic hunter-gatherers who were more limited in non-protein energy. Our conclusions are constrained by available data, but highlight the need for further studies, and suggest that our model provides an integrative framework for conceiving these studies.}, Doi = {10.1016/j.jhevol.2014.02.007}, Key = {fds337811} } @article{fds337817, Author = {Pontzer, H and Raichlen, DA and Gordon, AD and Schroepfer-Walker, KK and Hare, B and O'Neill, MC and Muldoon, KM and Dunsworth, HM and Wood, BM and Isler, K and Burkart, J and Irwin, M and Shumaker, RW and Lonsdorf, EV and Ross, SR}, Title = {Primate energy expenditure and life history.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {111}, Number = {4}, Pages = {1433-1437}, Year = {2014}, Month = {January}, url = {http://dx.doi.org/10.1073/pnas.1316940111}, Abstract = {Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates' slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates' slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that primates use remarkably little energy each day, expending on average only 50% of the energy expected for a placental mammal of similar mass. Such large differences in TEE are not easily explained by differences in physical activity, and instead appear to reflect systemic metabolic adaptation for low energy expenditures in primates. Indeed, comparisons of wild and captive primate populations indicate similar levels of energy expenditure. Broad interspecific comparisons of growth, reproduction, and maximum life span indicate that primates' slow metabolic rates contribute to their characteristically slow life histories.}, Doi = {10.1073/pnas.1316940111}, Key = {fds337817} } @article{fds337818, Author = {Pontzer, H}, Title = {Early hominin paleoecology. Edited by MattSponheimer, Julia A.Lee‐Thorp, Kaye E.Reed, and PeterUngar. 368 pp. Boulder, CO: University Press of Colorado. 2013. $70.00 (cloth), $56.00 (e‐book).}, Journal = {American Journal of Human Biology}, Volume = {26}, Number = {1}, Pages = {103-103}, Publisher = {Wiley}, Year = {2014}, Month = {January}, url = {http://dx.doi.org/10.1002/ajhb.22486}, Doi = {10.1002/ajhb.22486}, Key = {fds337818} } @article{fds337819, Author = {Pontzer, H and Raichlen, DA and Rodman, PS}, Title = {Bipedal and quadrupedal locomotion in chimpanzees.}, Journal = {Journal of human evolution}, Volume = {66}, Pages = {64-82}, Year = {2014}, Month = {January}, url = {http://dx.doi.org/10.1016/j.jhevol.2013.10.002}, Abstract = {Chimpanzees (Pan troglodytes) habitually walk both bipedally and quadrupedally, and have been a common point of reference for understanding the evolution of bipedal locomotion in early ape-like hominins. Here we compare the kinematics, kinetics, and energetics of bipedal and quadrupedal walking and running in a sample of five captive chimpanzees. Kinematics were recorded using sagittal-plane digital high-speed video of treadmill trials. Kinetics were recorded via a forceplate. Metabolic energy cost was measured via steady-state oxygen consumption during treadmill trials. Consistent with previous work on chimpanzees and other hominoids, we found that the spatiotemporal characteristics, joint angles, ground reaction forces, and metabolic cost of bipedal and quadrupedal locomotion are similar in chimpanzees. Notable differences include hip and trunk angles, which reflected a more orthograde trunk posture during bipedalism, and mediolateral ground reaction forces, which were larger during bipedal walking. Stride frequencies were also higher (and step lengths shorter) during bipedal trials. Bipedal and quadrupedal walking among chimpanzees was similar to that reported for bonobos, gibbons, and other primates. The similarity in cost between bipedal and quadrupedal trials suggests that the adoption of bipedal walking would have had no effect on walking costs for early ape-like hominins. However, habitual bipedalism may have favored modifications of the hip to allow a more orthograde posture, and of the hind limb abductor mechanisms to efficiently exert mediolateral ground forces.}, Doi = {10.1016/j.jhevol.2013.10.002}, Key = {fds337819} } @article{fds337820, Author = {Raichlen, DA and Wood, BM and Gordon, AD and Mabulla, AZP and Marlowe, FW and Pontzer, H}, Title = {Evidence of Levy walk foraging patterns in human hunter-gatherers.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {111}, Number = {2}, Pages = {728-733}, Year = {2014}, Month = {January}, url = {http://dx.doi.org/10.1073/pnas.1318616111}, Abstract = {When searching for food, many organisms adopt a superdiffusive, scale-free movement pattern called a Lévy walk, which is considered optimal when foraging for heterogeneously located resources with little prior knowledge of distribution patterns [Viswanathan GM, da Luz MGE, Raposo EP, Stanley HE (2011) The Physics of Foraging: An Introduction to Random Searches and Biological Encounters]. Although memory of food locations and higher cognition may limit the benefits of random walk strategies, no studies to date have fully explored search patterns in human foraging. Here, we show that human hunter-gatherers, the Hadza of northern Tanzania, perform Lévy walks in nearly one-half of all foraging bouts. Lévy walks occur when searching for a wide variety of foods from animal prey to underground tubers, suggesting that, even in the most cognitively complex forager on Earth, such patterns are essential to understanding elementary foraging mechanisms. This movement pattern may be fundamental to how humans experience and interact with the world across a wide range of ecological contexts, and it may be adaptive to food distribution patterns on the landscape, which previous studies suggested for organisms with more limited cognition. Additionally, Lévy walks may have become common early in our genus when hunting and gathering arose as a major foraging strategy, playing an important role in the evolution of human mobility.}, Doi = {10.1073/pnas.1318616111}, Key = {fds337820} } @article{fds337810, Author = {Pontzer, H and Suchman, K and Raichlen, DA and Wood, BM and Mabulla, AZP and Marlowe, FW}, Title = {Foot strike patterns and hind limb joint angles during running in Hadza hunter-gatherers}, Journal = {Journal of Sport and Health Science}, Volume = {3}, Number = {2}, Pages = {95-101}, Publisher = {Elsevier BV}, Year = {2014}, Month = {January}, url = {http://dx.doi.org/10.1016/j.jshs.2014.03.010}, Abstract = {Background: Investigations of running gait among barefoot and populations have revealed a diversity of foot strike behaviors, with some preferentially employing a rearfoot strike (RFS) as the foot touches down while others employ a midfoot strike (MFS) or forefoot strike (FFS). Here, we report foot strike behavior and joint angles among traditional Hadza hunter-gatherers living in Northern Tanzania. Methods: Hadza adults ( n=26) and juveniles ( n=14) ran at a range of speeds (adults: mean 3.4±0.7m/s, juveniles: mean 3.2±0.5 m/s) over an outdoor trackway while being recorded via high-speed digital video. Foot strike type (RFS, MFS, or FFS) and hind limb segment angles at foot strike were recorded. Results: Hadza men preferentially employed MFS (86.7% of men), while Hadza women and juveniles preferentially employed RFS (90.9% and 85.7% of women and juveniles, respectively). No FFS was recorded. Speed, the presence of footwear (sandals vs. barefoot), and trial duration had no effect on foot strike type. Conclusion: Unlike other habitually barefoot populations which prefer FFS while running, Hadza men preferred MFS, and Hadza women and juveniles preferred RFS. Sex and age differences in foot strike behavior among Hadza adults may reflect differences in running experience, with men learning to prefer MFS as they accumulate more running experience. © 2014 Shanghai University of Sport.}, Doi = {10.1016/j.jshs.2014.03.010}, Key = {fds337810} } @article{fds337821, Author = {Foster, AD and Raichlen, DA and Pontzer, H}, Title = {Muscle force production during bent-knee, bent-hip walking in humans.}, Journal = {Journal of human evolution}, Volume = {65}, Number = {3}, Pages = {294-302}, Year = {2013}, Month = {September}, url = {http://dx.doi.org/10.1016/j.jhevol.2013.06.012}, Abstract = {Researchers have long debated the locomotor posture used by the earliest bipeds. While many agree that by 3-4 Ma (millions of years ago), hominins walked with an extended-limb human style of bipedalism, researchers are still divided over whether the earliest bipeds walked like modern humans, or walked with a more bent-knee, bent-hip (BKBH) ape-like form of locomotion. Since more flexed postures are associated with higher energy costs, reconstructing early bipedal mechanics has implications for the selection pressures that led to upright walking. The purpose of this study is to determine how modern human anatomy functions in BKBH walking to clarify the links between morphology and energy costs in different mechanical regimes. Using inverse dynamics, we calculated muscle force production at the major limb joints in humans walking in two modes, both with extended limbs and BKBH. We found that in BKBH walking, humans must produce large muscle forces at the knee to support body weight, leading to higher estimated energy costs. However, muscle forces at the hip remained similar in BKBH and extended limb walking, suggesting that anatomical adaptations for hip extension in humans do not necessarily diminish the effective mechanical advantage at the hip in more flexed postures. We conclude that the key adaptations for economical walking, regardless of joint posture, seem to center on maintaining low muscle forces at the hip, primarily by keeping low external moments at the hip. We explore the implications of these results for interpreting locomotor energetics in early hominins, including australopithecines and Ardipithecus ramidus.}, Doi = {10.1016/j.jhevol.2013.06.012}, Key = {fds337821} } @article{fds337828, Author = {Barak, MM and Lieberman, DE and Raichlen, D and Pontzer, H and Warrener, AG and Hublin, J-J}, Title = {Trabecular evidence for a human-like gait in Australopithecus africanus.}, Journal = {PloS one}, Volume = {8}, Number = {11}, Pages = {e77687}, Year = {2013}, Month = {January}, url = {http://dx.doi.org/10.1371/journal.pone.0077687}, Abstract = {Although the earliest known hominins were apparently upright bipeds, there has been mixed evidence whether particular species of hominins including those in the genus Australopithecus walked with relatively extended hips, knees and ankles like modern humans, or with more flexed lower limb joints like apes when bipedal. Here we demonstrate in chimpanzees and humans a highly predictable and sensitive relationship between the orientation of the ankle joint during loading and the principal orientation of trabecular bone struts in the distal tibia that function to withstand compressive forces within the joint. Analyses of the orientation of these struts using microCT scans in a sample of fossil tibiae from the site of Sterkfontein, of which two are assigned to Australopithecus africanus, indicate that these hominins primarily loaded their ankles in a relatively extended posture like modern humans and unlike chimpanzees. In other respects, however, trabecular properties in Au africanus are distinctive, with values that mostly fall between those of chimpanzees and humans. These results indicate that Au. africanus, like Homo, walked with an efficient, extended lower limb.}, Doi = {10.1371/journal.pone.0077687}, Key = {fds337828} } @article{fds337829, Author = {Raichlen, DA and Pontzer, H and Shapiro, LJ}, Title = {A new look at the Dynamic Similarity Hypothesis: the importance of swing phase.}, Journal = {Biology open}, Volume = {2}, Number = {10}, Pages = {1032-1036}, Year = {2013}, Month = {January}, url = {http://dx.doi.org/10.1242/bio.20135165}, Abstract = {The Dynamic Similarity Hypothesis (DSH) suggests that when animals of different size walk at similar Froude numbers (equal ratios of inertial and gravitational forces) they will use similar size-corrected gaits. This application of similarity theory to animal biomechanics has contributed to fundamental insights in the mechanics and evolution of a diverse set of locomotor systems. However, despite its popularity, many mammals fail to walk with dynamically similar stride lengths, a key element of gait that determines spontaneous speed and energy costs. Here, we show that the applicability of the DSH is dependent on the inertial forces examined. In general, the inertial forces are thought to be the centripetal force of the inverted pendulum model of stance phase, determined by the length of the limb. If instead we model inertial forces as the centripetal force of the limb acting as a suspended pendulum during swing phase (determined by limb center of mass position), the DSH for stride length variation is fully supported. Thus, the DSH shows that inter-specific differences in spatial kinematics are tied to the evolution of limb mass distribution patterns. Selection may act on morphology to produce a given stride length, or alternatively, stride length may be a "spandrel" of selection acting on limb mass distribution.}, Doi = {10.1242/bio.20135165}, Key = {fds337829} } @article{fds337830, Author = {Pontzer, H}, Title = {Ecological energetics in early Homo}, Journal = {Current Anthropology}, Volume = {53}, Number = {SUPPL. 6}, Pages = {S346-S358}, Publisher = {University of Chicago Press}, Year = {2012}, Month = {December}, url = {http://dx.doi.org/10.1086/667402}, Abstract = {Models for the origin of the genus Homo propose that increased quality of diet led to changes in ranging ecology and selection for greater locomotor economy, speed, and endurance. Here, I examine the fossil evidence for postcranial change in early Homo and draw on comparative data from living mammals to assess whether increased diet quality has led to selection for improved locomotor performance in other lineages. Body mass estimates indicate early Homo, both males and females, were approximately 33% larger than australopiths, consistent with archeological evidence indicating an ecological change with the origins of our genus. However, many of the postcranial features thought to be derived in Homo, including longer hind limbs, are present in Australopithecus, challenging the hypothesis that early Homo is marked by significant change in walking and running performance. Analysis of energy budgets across mammals suggests that the larger body mass and increased diet quality in early Homo may reflect an increase in the hominin energy budget. Expanding the energy budget would enable greater investment in reproduction without decreasing energy available for larger brains or increased activity. Food sharing and increased adiposity, which decrease variance in food energy availability, may have been integral to this metabolic strategy. © 2012 by The Wenner-Gren Foundation for Anthropological Research.All rights reserved.}, Doi = {10.1086/667402}, Key = {fds337830} } @article{fds337831, Author = {Dunsworth, HM and Warrener, AG and Deacon, T and Ellison, PT and Pontzer, H}, Title = {Metabolic hypothesis for human altriciality.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {109}, Number = {38}, Pages = {15212-15216}, Year = {2012}, Month = {September}, url = {http://dx.doi.org/10.1073/pnas.1205282109}, Abstract = {The classic anthropological hypothesis known as the "obstetrical dilemma" is a well-known explanation for human altriciality, a condition that has significant implications for human social and behavioral evolution. The hypothesis holds that antagonistic selection for a large neonatal brain and a narrow, bipedal-adapted birth canal poses a problem for childbirth; the hominin "solution" is to truncate gestation, resulting in an altricial neonate. This explanation for human altriciality based on pelvic constraints persists despite data linking human life history to that of other species. Here, we present evidence that challenges the importance of pelvic morphology and mechanics in the evolution of human gestation and altriciality. Instead, our analyses suggest that limits to maternal metabolism are the primary constraints on human gestation length and fetal growth. Although pelvic remodeling and encephalization during hominin evolution contributed to the present parturitional difficulty, there is little evidence that pelvic constraints have altered the timing of birth.}, Doi = {10.1073/pnas.1205282109}, Key = {fds337831} } @article{fds337832, Author = {Pontzer, H}, Title = {Relating ranging ecology, limb length, and locomotor economy in terrestrial animals.}, Journal = {Journal of theoretical biology}, Volume = {296}, Pages = {6-12}, Year = {2012}, Month = {March}, url = {http://dx.doi.org/10.1016/j.jtbi.2011.11.018}, Abstract = {Ecomorphological analyses have identified a number of important evolutionary trends in vertebrate limb design, but the relationships between daily travel distance, locomotor ecology, and limb length in terrestrial animals remain poorly understood. In this paper I model the net rate of energy intake as a function of foraging efficiency, and thus of locomotor economy; improved economy leads to greater net energy intake. However, the relationship between locomotor economy and net intake is highly dependent on foraging efficiency; only species with low foraging efficiencies experience strong selection pressure for improved locomotor economy and increased limb length. Examining 237 terrestrial species, I find that nearly all taxa obtain sufficiently high foraging efficiencies that selection for further increases in economy is weak. Thus selection pressures for increased economy and limb length among living terrestrial animals may be relatively weak and similar in magnitude across ecologically diverse species. The Economy Selection Pressure model for locomotor economy may be useful in investigating the evolution of limb design in early terrestrial taxa and the coevolution of foraging ecology and locomotor anatomy in lineages with low foraging efficiencies.}, Doi = {10.1016/j.jtbi.2011.11.018}, Key = {fds337832} } @article{fds337837, Author = {Pontzer, H and Raichlen, DA and Wood, BM and Mabulla, AZP and Racette, SB and Marlowe, FW}, Title = {Hunter-gatherer energetics and human obesity.}, Journal = {PloS one}, Volume = {7}, Number = {7}, Pages = {e40503}, Year = {2012}, Month = {January}, url = {http://dx.doi.org/10.1371/journal.pone.0040503}, Abstract = {Western lifestyles differ markedly from those of our hunter-gatherer ancestors, and these differences in diet and activity level are often implicated in the global obesity pandemic. However, few physiological data for hunter-gatherer populations are available to test these models of obesity. In this study, we used the doubly-labeled water method to measure total daily energy expenditure (kCal/day) in Hadza hunter-gatherers to test whether foragers expend more energy each day than their Western counterparts. As expected, physical activity level, PAL, was greater among Hadza foragers than among Westerners. Nonetheless, average daily energy expenditure of traditional Hadza foragers was no different than that of Westerners after controlling for body size. The metabolic cost of walking (kcal kg(-1) m(-1)) and resting (kcal kg(-1) s(-1)) were also similar among Hadza and Western groups. The similarity in metabolic rates across a broad range of cultures challenges current models of obesity suggesting that Western lifestyles lead to decreased energy expenditure. We hypothesize that human daily energy expenditure may be an evolved physiological trait largely independent of cultural differences.}, Doi = {10.1371/journal.pone.0040503}, Key = {fds337837} } @article{fds337838, Author = {Pontzer, H and Scott, JR and Lordkipanidze, D and Ungar, PS}, Title = {Dental microwear texture analysis and diet in the Dmanisi hominins.}, Journal = {Journal of human evolution}, Volume = {61}, Number = {6}, Pages = {683-687}, Year = {2011}, Month = {December}, url = {http://dx.doi.org/10.1016/j.jhevol.2011.08.006}, Abstract = {Reconstructions of foraging behavior and diet are central to our understanding of fossil hominin ecology and evolution. Current hypotheses for the evolution of the genus Homo invoke a change in foraging behavior to include higher quality foods. Recent microwear texture analyses of fossil hominin teeth have suggested that the evolution of Homo erectus may have been marked by a transition to a more variable diet. In this study, we used microwear texture analysis to examine the occlusal surface of 2 molars from Dmanisi, a 1.8 million year old fossil hominin site in the Republic of Georgia. The Dmanisi molars were characterized by a moderate degree of surface complexity (Asfc), low textural fill volume (Tfv), and a relatively low scale of maximum complexity (Smc), similar to specimens of early African H. erectus. While caution must be used in drawing conclusions from this small sample (n = 2), these results are consistent with continuity in diet as H. erectus expanded into Eurasia.}, Doi = {10.1016/j.jhevol.2011.08.006}, Key = {fds337838} } @article{fds337839, Author = {Orkin, JD and Pontzer, H}, Title = {The Narrow Niche hypothesis: gray squirrels shed new light on primate origins.}, Journal = {American journal of physical anthropology}, Volume = {144}, Number = {4}, Pages = {617-624}, Year = {2011}, Month = {April}, url = {http://dx.doi.org/10.1002/ajpa.21450}, Abstract = {Current hypotheses for primate origins propose that nails and primate-like grasping hands and feet were important early adaptations for feeding in fine branches. Comparative research in this area has focused on instances of convergence in extant animals, showing that species with primate-like morphology feed predominantly from terminal branches. Little has been done to test whether animals without primate-like morphology engage in similar behavior. We tested the fine-branch niche hypothesis for primate origins by observing branch use in Eastern gray squirrels, Sciurus carolinensis, a species lacking primate grasping adaptations that has been understudied in the context of primate origins. We hypothesized that because gray squirrels lack primate-like grasping adaptations, they would avoid feeding and foraging in terminal branches. Instantaneous focal animal sampling was used to examine the locomotor and postural behaviors used while feeding and foraging. Our results demonstrate habitual and effective usage of terminal branches by gray squirrels while feeding and foraging, primarily on tree seeds (e.g., oak, maple, and elm). Discriminant function analysis indicates that gray squirrels feed and forage like primates, unlike some other tree squirrel species. Given the absence of primate-like features in gray squirrels, we suggest that although selection for fine-branch foraging may be a necessary condition for primate origins, it is not sufficient. We propose an alternative model of primate origins. The Narrow Niche hypothesis suggests that the primate morphological suite evolved not only from selection pressure for fine branch use, but also from a lack of engagement in other activities.}, Doi = {10.1002/ajpa.21450}, Key = {fds337839} } @article{fds337848, Author = {Cowgill, LW and Warrener, A and Pontzer, H and Ocobock, C}, Title = {Waddling and toddling: the biomechanical effects of an immature gait.}, Journal = {American journal of physical anthropology}, Volume = {143}, Number = {1}, Pages = {52-61}, Year = {2010}, Month = {September}, url = {http://dx.doi.org/10.1002/ajpa.21289}, Abstract = {Femoral shape changes during the course of human growth, transitioning from a subcircular tube to a teardrop-shaped diaphysis with a posterior pilaster. Differences between immature and mature bipedalism and body shape may generate different loads, which, in turn, may influence femoral modeling and remodeling during the course of the human lifespan. This study uses two different approaches to evaluate the hypotheses that differences in gait between young and mature walkers result in differences in ground reaction forces (GRFs) and that the differences in loading regimes between young children and adults will be reflected in the geometric structure of the midshaft femur. The results of this analysis indicate that GRFs differ between young walkers and adults in that normalized mediolateral (ML) forces are significantly higher in younger age groups. In addition, these differences between children and adults in the relative level of ML bending force are reflected in changes in femoral geometry during growth. During the earlier stages of human development, immature femoral diaphyses are heavily reinforced in approximately ML plane. The differences in gait between mature and immature walkers, and hence the differences in femoral shape, are likely partially a product of a minimal bicondylar angle and relatively broad body in young children.}, Doi = {10.1002/ajpa.21289}, Key = {fds337848} } @article{fds337849, Author = {Pontzer, H and Raichlen, DA and Shumaker, RW and Ocobock, C and Wich, SA}, Title = {Metabolic adaptation for low energy throughput in orangutans.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {107}, Number = {32}, Pages = {14048-14052}, Year = {2010}, Month = {August}, url = {http://dx.doi.org/10.1073/pnas.1001031107}, Abstract = {Energy is the fundamental currency of life--needed for growth, repair, and reproduction--but little is known about the metabolic physiology and evolved energy use strategies of the great apes, our closest evolutionary relatives. Here we report daily energy use in free-living orangutans (Pongo spp.) and test whether observed differences in energy expenditure among orangutans, humans, and other mammals reflect known differences in life history. Using the doubly labeled water method, we measured daily energy expenditure (kCal/d) in orangutans living in a large indoor/outdoor habitat at the Great Ape Trust. Despite activity levels similar to orangutans in the wild, Great Ape Trust orangutans used less energy, relative to body mass, than nearly any eutherian mammal ever measured, including sedentary humans. Such an extremely low rate of energy use has not been observed previously in primates, but is consistent with the slow growth and low rate of reproduction in orangutans, and may be an evolutionary response to severe food shortages in their native Southeast Asian rainforests. These results hold important implications for the management of orangutan populations in captivity and in the wild, and underscore the flexibility and interdependence of physiological, behavioral, and life history strategies in the evolution of apes and humans.}, Doi = {10.1073/pnas.1001031107}, Key = {fds337849} } @article{fds337850, Author = {Pontzer, H and Rolian, C and Rightmire, GP and Jashashvili, T and Ponce de León, MS and Lordkipanidze, D and Zollikofer, CPE}, Title = {Locomotor anatomy and biomechanics of the Dmanisi hominins.}, Journal = {Journal of human evolution}, Volume = {58}, Number = {6}, Pages = {492-504}, Year = {2010}, Month = {June}, url = {http://dx.doi.org/10.1016/j.jhevol.2010.03.006}, Abstract = {The Dmanisi hominins inhabited a northern temperate habitat in the southern Caucasus, approximately 1.8 million years ago. This is the oldest population of hominins known outside of Africa. Understanding the set of anatomical and behavioral traits that equipped this population to exploit their seasonal habitat successfully may shed light on the selection pressures shaping early members of the genus Homo and the ecological strategies that permitted the expansion of their range outside of the African subtropics. The abundant stone tools at the site, as well as taphonomic evidence for butchery, suggest that the Dmanisi hominins were active hunters or scavengers. In this study, we examine the locomotor mechanics of the Dmanisi hind limb to test the hypothesis that the inclusion of meat in the diet is associated with an increase in walking and running economy and endurance. Using comparative data from modern humans, chimpanzees, and gorillas, as well as other fossil hominins, we show that the Dmanisi hind limb was functionally similar to modern humans, with a longitudinal plantar arch, increased limb length, and human-like ankle morphology. Other aspects of the foot, specifically metatarsal morphology and tibial torsion, are less derived and similar to earlier hominins. These results are consistent with hypotheses linking hunting and scavenging to improved walking and running performance in early Homo. Primitive retentions in the Dmanisi foot suggest that locomotor evolution continued through the early Pleistocene.}, Doi = {10.1016/j.jhevol.2010.03.006}, Key = {fds337850} } @article{fds337864, Author = {Pontzer, H and Allen, V and Hutchinson, JR}, Title = {Biomechanics of running indicates endothermy in bipedal dinosaurs.}, Journal = {PloS one}, Volume = {4}, Number = {11}, Pages = {e7783}, Year = {2009}, Month = {November}, url = {http://dx.doi.org/10.1371/journal.pone.0007783}, Abstract = {<h4>Background</h4>One of the great unresolved controversies in paleobiology is whether extinct dinosaurs were endothermic, ectothermic, or some combination thereof, and when endothermy first evolved in the lineage leading to birds. Although it is well established that high, sustained growth rates and, presumably, high activity levels are ancestral for dinosaurs and pterosaurs (clade Ornithodira), other independent lines of evidence for high metabolic rates, locomotor costs, or endothermy are needed. For example, some studies have suggested that, because large dinosaurs may have been homeothermic due to their size alone and could have had heat loss problems, ectothermy would be a more plausible metabolic strategy for such animals.<h4>Methodology/principal findings</h4>Here we describe two new biomechanical approaches for reconstructing the metabolic rate of 14 extinct bipedal dinosauriforms during walking and running. These methods, well validated for extant animals, indicate that during walking and slow running the metabolic rate of at least the larger extinct dinosaurs exceeded the maximum aerobic capabilities of modern ectotherms, falling instead within the range of modern birds and mammals. Estimated metabolic rates for smaller dinosaurs are more ambiguous, but generally approach or exceed the ectotherm boundary.<h4>Conclusions/significance</h4>Our results support the hypothesis that endothermy was widespread in at least larger non-avian dinosaurs. It was plausibly ancestral for all dinosauriforms (perhaps Ornithodira), but this is perhaps more strongly indicated by high growth rates than by locomotor costs. The polarity of the evolution of endothermy indicates that rapid growth, insulation, erect postures, and perhaps aerobic power predated advanced "avian" lung structure and high locomotor costs.}, Doi = {10.1371/journal.pone.0007783}, Key = {fds337864} } @article{fds337854, Author = {Raichlen, DA and Pontzer, H and Shapiro, LJ and Sockol, MD}, Title = {Understanding hind limb weight support in chimpanzees with implications for the evolution of primate locomotion.}, Journal = {American journal of physical anthropology}, Volume = {138}, Number = {4}, Pages = {395-402}, Year = {2009}, Month = {April}, url = {http://dx.doi.org/10.1002/ajpa.20952}, Abstract = {Most quadrupedal mammals support a larger amount of body weight on their forelimbs compared with their hind limbs during locomotion, whereas most primates support more of their body weight on their hind limbs. Increased hind limb weight support is generally interpreted as an adaptation that reduces stress on primates' highly mobile forelimb joints. Thus, increased hind limb weight support was likely vital for the evolution of primate arboreality. Despite its evolutionary importance, the mechanism used by primates to achieve this important kinetic pattern remains unclear. Here, we examine weight support patterns in a sample of chimpanzees (Pan troglodytes) to test the hypothesis that limb position, combined with whole body center of mass position (COM), explains increased hind limb weight support in this taxon. Chimpanzees have a COM midway between their shoulders and hips and walk with a relatively protracted hind limb and a relatively vertical forelimb, averaged over a step. Thus, the limb kinematics of chimpanzees brings their feet closer to the COM than their hands, generating greater hind limb weight support. Comparative data suggest that these same factors likely explain weight support patterns for a broader sample of primates. It remains unclear whether primates use these limb kinematics to increase hind limb weight support, or whether they are byproducts of other gait characteristics. The latter hypothesis raises the intriguing possibility that primate weight support patterns actually evolved as byproducts of other traits, or spandrels, rather than as adaptations to increase forelimb mobility.}, Doi = {10.1002/ajpa.20952}, Key = {fds337854} } @article{fds337855, Author = {Pontzer, H and Holloway IV and JH and Raichlen, DA and Lieberman, DE}, Title = {Control and function of arm swing in human walking and running (Journal of Experimental Biology 212 (523-534))}, Journal = {Journal of Experimental Biology}, Volume = {212}, Number = {6}, Pages = {894}, Publisher = {The Company of Biologists}, Year = {2009}, Month = {March}, url = {http://dx.doi.org/10.1242/jeb.030478}, Doi = {10.1242/jeb.030478}, Key = {fds337855} } @article{fds337858, Author = {Pontzer, H and Holloway, JH and Raichlen, DA and Lieberman, DE}, Title = {Control and function of arm swing in human walking and running.}, Journal = {The Journal of experimental biology}, Volume = {212}, Number = {Pt 4}, Pages = {523-534}, Year = {2009}, Month = {February}, url = {http://dx.doi.org/10.1242/jeb.024927}, Abstract = {We investigated the control and function of arm swing in human walking and running to test the hypothesis that the arms act as passive mass dampers powered by movement of the lower body, rather than being actively driven by the shoulder muscles. We measured locomotor cost, deltoid muscle activity and kinematics in 10 healthy adult subjects while walking and running on a treadmill in three experimental conditions: control; no arms (arms folded across the chest); and arm weights (weights worn at the elbow). Decreasing and increasing the moment of inertia of the upper body in no arms and arm weights conditions, respectively, had corresponding effects on head yaw and on the phase differences between shoulder and pelvis rotation, consistent with the view of arms as mass dampers. Angular acceleration of the shoulders and arm increased with torsion of the trunk and shoulder, respectively, but angular acceleration of the shoulders was not inversely related to angular acceleration of the pelvis or arm. Restricting arm swing in no arms trials had no effect on locomotor cost. Anterior and posterior portions of the deltoid contracted simultaneously rather than firing alternately to drive the arm. These results support a passive arm swing hypothesis for upper body movement during human walking and running, in which the trunk and shoulders act primarily as elastic linkages between the pelvis, shoulder girdle and arms, the arms act as passive mass dampers which reduce torso and head rotation, and upper body movement is primarily powered by lower body movement.}, Doi = {10.1242/jeb.024927}, Key = {fds337858} } @article{fds337865, Author = {Pontzer, H and Raichlen, DA and Sockol, MD}, Title = {The metabolic cost of walking in humans, chimpanzees, and early hominins.}, Journal = {Journal of human evolution}, Volume = {56}, Number = {1}, Pages = {43-54}, Year = {2009}, Month = {January}, url = {http://dx.doi.org/10.1016/j.jhevol.2008.09.001}, Abstract = {Bipedalism is a defining feature of the hominin lineage, but the nature and efficiency of early hominin walking remains the focus of much debate. Here, we investigate walking cost in early hominins using experimental data from humans and chimpanzees. We use gait and energetics data from humans, and from chimpanzees walking bipedally and quadrupedally, to test a new model linking locomotor anatomy and posture to walking cost. We then use this model to reconstruct locomotor cost for early, ape-like hominins and for the A.L. 288 Australopithecus afarensis specimen. Results of the model indicate that hind limb length, posture (effective mechanical advantage), and muscle fascicle length contribute nearly equally to differences in walking cost between humans and chimpanzees. Further, relatively small changes in these variables would decrease the cost of bipedalism in an early chimpanzee-like biped below that of quadrupedal apes. Estimates of walking cost in A.L. 288, over a range of hypothetical postures from crouched to fully extended, are below those of quadrupedal apes, but above those of modern humans. These results indicate that walking cost in early hominins was likely similar to or below that of their quadrupedal ape-like forebears, and that by the mid-Pliocene, hominin walking was less costly than that of other apes. This supports the hypothesis that locomotor energy economy was an important evolutionary pressure on hominin bipedalism.}, Doi = {10.1016/j.jhevol.2008.09.001}, Key = {fds337865} } @article{fds337866, Author = {Pontzer, H and Kamilar, JM}, Title = {Great ranging associated with greater reproductive investment in mammals.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {106}, Number = {1}, Pages = {192-196}, Year = {2009}, Month = {January}, url = {http://dx.doi.org/10.1073/pnas.0806105106}, Abstract = {Most animals must travel to find food, incurring an unavoidable energy and time cost. Economic theory predicts, and experimental work confirms, that within species, increasing the distance traveled each day to find food has negative fitness consequences, decreasing the amount of energy invested in maintenance, repair, and reproduction. Here, we show that this relationship between daily distance traveled and reproductive success is fundamentally different between species and over evolutionary time in many lineages. Phylogenetically controlled analyses of 161 eutherian mammals indicate that, after controlling for body mass, evolutionary increases in the daily distance traveled are associated with corresponding increases in both total fertility (number of offspring per lifetime) and total offspring mass (grams of offspring per lifetime). This suggests that over evolutionary time, increasing travel distance is often part of a strategy for procuring more food energy and not necessarily a response to decreased food availability. These results have important implications for ecological comparisons among species, including assessments of habitat quality based on locomotor behavior.}, Doi = {10.1073/pnas.0806105106}, Key = {fds337866} } @article{fds337868, Author = {Carter, ML and Pontzer, H and Wrangham, RW and Peterhans, JK}, Title = {Skeletal pathology in Pan troglodytes schweinfurthii in Kibale National Park, Uganda.}, Journal = {American journal of physical anthropology}, Volume = {135}, Number = {4}, Pages = {389-403}, Year = {2008}, Month = {April}, url = {http://dx.doi.org/10.1002/ajpa.20758}, Abstract = {The ecological pressures shaping chimpanzee anatomy and behavior are the subject of much discussion in primatology and paleoanthropology, yet empirical data on fundamental parameters including body size, morbidity, and mortality are rare for wild chimpanzees. Here, we present skeletal pathology and body size data for 20 (19 crania, 12 postcrania) chimpanzees (Pan troglodytes schweinfurthii) from Kibale National Park, Uganda. We compare these data with other East African populations, especially Gombe National Park. Estimated body size for Kibale chimpanzees was similar to other East African populations and significantly larger than Gombe chimpanzees. The high rates of trauma and other skeletal pathology evident in the Kibale chimpanzee skeletons were similar to those in the Gombe skeletal sample. Much of the major skeletal trauma in the Kibale skeletons was attributable to falls, although other pathologies were noted as well, including apparent injuries from snares, degenerative arthritis, and minor congenital abnormalities.}, Doi = {10.1002/ajpa.20758}, Key = {fds337868} } @article{fds337874, Author = {Raichlen, DA and Pontzer, H and Sockol, MD}, Title = {The Laetoli footprints and early hominin locomotor kinematics.}, Journal = {Journal of human evolution}, Volume = {54}, Number = {1}, Pages = {112-117}, Year = {2008}, Month = {January}, url = {http://dx.doi.org/10.1016/j.jhevol.2007.07.005}, Abstract = {A critical question in human evolution is whether the earliest bipeds walked with a bent-hip, bent-knee gait or on more extended hindlimbs. The differences between these gaits are not trivial, because the adoption of either has important implications for the evolution of bipedalism. In this study, we re-examined the Laetoli footprints to determine whether they can provide information on the locomotor posture of early hominins. Previous researchers have suggested that the stride lengths of Laetoli hominins fall within the range of modern human stride lengths and therefore, Laetoli hominins walked with modern-human-like kinematics. Using a dynamic-similarity analysis, we compared Laetoli hominin stride lengths with those of both modern humans and chimpanzees. Our results indicate that Laetoli hominins could have used either a bent-hip, bent-knee gait, similar to a chimpanzee, or an extended-hindlimb gait, similar to a human. In fact, our data suggest that the Laetoli hominins could have walked near their preferred speeds using either limb posture. This result contrasts with most previous studies, which suggest relatively slow walking speeds for these early bipeds. Despite the many attempts to discern limb-joint kinematics from Laetoli stride lengths, our study concludes that stride lengths alone do not resolve the debate over early hominin locomotor postures.}, Doi = {10.1016/j.jhevol.2007.07.005}, Key = {fds337874} } @article{fds337876, Author = {Lordkipanidze, D and Jashashvili, T and Vekua, A and Ponce de León, MS and Zollikofer, CPE and Rightmire, GP and Pontzer, H and Ferring, R and Oms, O and Tappen, M and Bukhsianidze, M and Agusti, J and Kahlke, R and Kiladze, G and Martinez-Navarro, B and Mouskhelishvili, A and Nioradze, M and Rook, L}, Title = {Postcranial evidence from early Homo from Dmanisi, Georgia.}, Journal = {Nature}, Volume = {449}, Number = {7160}, Pages = {305-310}, Year = {2007}, Month = {September}, url = {http://dx.doi.org/10.1038/nature06134}, Abstract = {The Plio-Pleistocene site of Dmanisi, Georgia, has yielded a rich fossil and archaeological record documenting an early presence of the genus Homo outside Africa. Although the craniomandibular morphology of early Homo is well known as a result of finds from Dmanisi and African localities, data about its postcranial morphology are still relatively scarce. Here we describe newly excavated postcranial material from Dmanisi comprising a partial skeleton of an adolescent individual, associated with skull D2700/D2735, and the remains from three adult individuals. This material shows that the postcranial anatomy of the Dmanisi hominins has a surprising mosaic of primitive and derived features. The primitive features include a small body size, a low encephalization quotient and absence of humeral torsion; the derived features include modern-human-like body proportions and lower limb morphology indicative of the capability for long-distance travel. Thus, the earliest known hominins to have lived outside of Africa in the temperate zones of Eurasia did not yet display the full set of derived skeletal features.}, Doi = {10.1038/nature06134}, Key = {fds337876} } @article{fds337877, Author = {Sockol, MD and Raichlen, DA and Pontzer, H}, Title = {Chimpanzee locomotor energetics and the origin of human bipedalism.}, Journal = {Proceedings of the National Academy of Sciences of the United States of America}, Volume = {104}, Number = {30}, Pages = {12265-12269}, Year = {2007}, Month = {July}, url = {http://dx.doi.org/10.1073/pnas.0703267104}, Abstract = {Bipedal walking is evident in the earliest hominins [Zollikofer CPE, Ponce de Leon MS, Lieberman DE, Guy F, Pilbeam D, et al. (2005) Nature 434:755-759], but why our unique two-legged gait evolved remains unknown. Here, we analyze walking energetics and biomechanics for adult chimpanzees and humans to investigate the long-standing hypothesis that bipedalism reduced the energy cost of walking compared with our ape-like ancestors [Rodman PS, McHenry HM (1980) Am J Phys Anthropol 52:103-106]. Consistent with previous work on juvenile chimpanzees [Taylor CR, Rowntree VJ (1973) Science 179:186-187], we find that bipedal and quadrupedal walking costs are not significantly different in our sample of adult chimpanzees. However, a more detailed analysis reveals significant differences in bipedal and quadrupedal cost in most individuals, which are masked when subjects are examined as a group. Furthermore, human walking is approximately 75% less costly than both quadrupedal and bipedal walking in chimpanzees. Variation in cost between bipedal and quadrupedal walking, as well as between chimpanzees and humans, is well explained by biomechanical differences in anatomy and gait, with the decreased cost of human walking attributable to our more extended hip and a longer hindlimb. Analyses of these features in early fossil hominins, coupled with analyses of bipedal walking in chimpanzees, indicate that bipedalism in early, ape-like hominins could indeed have been less costly than quadrupedal knucklewalking.}, Doi = {10.1073/pnas.0703267104}, Key = {fds337877} } @article{fds337878, Author = {Pontzer, H}, Title = {Effective limb length and the scaling of locomotor cost in terrestrial animals.}, Journal = {The Journal of experimental biology}, Volume = {210}, Number = {Pt 10}, Pages = {1752-1761}, Year = {2007}, Month = {May}, url = {http://dx.doi.org/10.1242/jeb.002246}, Abstract = {Relative to body size, smaller animals use more energy to travel a given distance than larger animals, but the anatomical variable driving this negative allometry remains the subject of debate. Here, I report a simple inverse relationship between effective limb length (i.e. hip height) and the energy cost of transport (COT; J kg(-1) m(-1)) for terrestrial animals. Using published data for a diverse set of terrestrial species including birds, mammals, reptiles and arthropods, I show that between-species differences in locomotor cost are driven by differences in limb length. Notably, there is no independent effect of body mass on cost. Remarkably, effective limb length explains 98% of the observed variance in locomotor cost across a wide range of terrestrial species including mammals, birds, reptiles and arthropods. Variation about the limb-length/COT scaling relationship is attributable to taxonomic differences in limb design, with birds and arthropods exhibiting greater residuals than mammals. Differences in COT between semi-aquatic, generalist and cursorial species also corresponds to differences in leg length between these groups. These results are discussed in light of previous investigations of the limb length and locomotor cost.}, Doi = {10.1242/jeb.002246}, Key = {fds337878} } @article{fds337879, Author = {Pontzer, H}, Title = {Predicting the energy cost of terrestrial locomotion: a test of the LiMb model in humans and quadrupeds.}, Journal = {The Journal of experimental biology}, Volume = {210}, Number = {Pt 3}, Pages = {484-494}, Year = {2007}, Month = {February}, url = {http://dx.doi.org/10.1242/jeb.02662}, Abstract = {The energy cost of terrestrial locomotion has been linked to the muscle forces generated to support body weight and swing the limbs. The LiMb model predicts these forces, and hence locomotor cost, as a function of limb length and basic kinematic variables. Here, I test this model in humans, goats and dogs in order to assess the performance of the LiMb model in predicting locomotor cost for bipeds and quadrupeds. Model predictions were compared to observed locomotor cost, measured via oxygen consumption, during treadmill trials performed over a range of speeds for both walking and running gaits. The LiMb model explained more of the variation in locomotor cost than other predictors, including contact time, Froude number and body mass. The LiMb model also accurately predicted the magnitude of vertical ground forces. Results suggest the LiMb model reliably links locomotor anatomy to force production and locomotor cost. Further, these data support the idea that limb length may underlie the scaling of locomotor cost for terrestrial animals.}, Doi = {10.1242/jeb.02662}, Key = {fds337879} } @article{fds337885, Author = {Lieberman, DE and Raichlen, DA and Pontzer, H and Bramble, DM and Cutright-Smith, E}, Title = {The human gluteus maximus and its role in running.}, Journal = {The Journal of experimental biology}, Volume = {209}, Number = {Pt 11}, Pages = {2143-2155}, Year = {2006}, Month = {June}, url = {http://dx.doi.org/10.1242/jeb.02255}, Abstract = {The human gluteus maximus is a distinctive muscle in terms of size, anatomy and function compared to apes and other non-human primates. Here we employ electromyographic and kinematic analyses of human subjects to test the hypothesis that the human gluteus maximus plays a more important role in running than walking. The results indicate that the gluteus maximus is mostly quiescent with low levels of activity during level and uphill walking, but increases substantially in activity and alters its timing with respect to speed during running. The major functions of the gluteus maximus during running are to control flexion of the trunk on the stance-side and to decelerate the swing leg; contractions of the stance-side gluteus maximus may also help to control flexion of the hip and to extend the thigh. Evidence for when the gluteus maximus became enlarged in human evolution is equivocal, but the muscle's minimal functional role during walking supports the hypothesis that enlargement of the gluteus maximus was likely important in the evolution of hominid running capabilities.}, Doi = {10.1242/jeb.02255}, Key = {fds337885} } @article{fds337886, Author = {Pontzer, H and Wrangham, RW}, Title = {Ontogeny of ranging in wild chimpanzees}, Journal = {International Journal of Primatology}, Volume = {27}, Number = {1}, Pages = {295-309}, Year = {2006}, Month = {February}, url = {http://dx.doi.org/10.1007/s10764-005-9011-2}, Abstract = {We examined the relationship between juvenile age and distance traveled per day, or day range, in Kanyawara chimpanzees. Because the energy cost of locomotion is greater for small-bodied animals, we predict that day range is constrained by body size, i.e., younger individuals tend to have shorter day ranges. To test this hypothesis, we measured day range for 200 day-ranges of groups in which we recorded the age of the youngest juvenile present. As predicted, day range correlated positively with age for juveniles. Comparisons of day range vs. estimated stature support the hypothesis that the increase in day range with age was a consequence of body size. To assess other sources of variation in day range, we also measured the effects of group size and the presence of a carried infant. While day range correlated significantly with group size, the presence of a carried infant had no effect on adult female day range. Our results suggest the size of a juvenile may constrain ranging for mothers and their offspring. © 2006 Springer Science+Business Media, Inc.}, Doi = {10.1007/s10764-005-9011-2}, Key = {fds337886} } @article{fds337889, Author = {Pontzer, H and Lieberman, DE and Momin, E and Devlin, MJ and Polk, JD and Hallgrímsson, B and Cooper, DML}, Title = {Trabecular bone in the bird knee responds with high sensitivity to changes in load orientation.}, Journal = {The Journal of experimental biology}, Volume = {209}, Number = {Pt 1}, Pages = {57-65}, Year = {2006}, Month = {January}, url = {http://dx.doi.org/10.1242/jeb.01971}, Abstract = {Wolff's law of trajectorial orientation proposes that trabecular struts align with the orientation of dominant compressive loads within a joint. Although widely considered in skeletal biology, Wolff's law has never been experimentally tested while controlling for ontogenetic stage, activity level, and species differences, all factors that may affect trabecular bone growth. Here we report an experimental test of Wolff's law using a within-species design in age-matched subjects experiencing physiologically normal levels of bone strain. Two age-matched groups of juvenile guinea fowl Numida meleagris ran on a treadmill set at either 0 degrees (Level group) or 20 degrees (Incline group), for 10 min per day over a 45-day treatment period. Birds running on the 20 degrees inclined treadmill used more-flexed knees than those in the Level group at midstance (the point of peak ground reaction force). This difference in joint posture enabled us to test the sensitivity of trabecular alignment to altered load orientation in the knee. Using a new radon transform-based method for measuring trabecular orientation, our analysis shows that the fine trabecular bone in the distal femur has a high degree of correspondence between changes in joint angle and trabecular orientation. The sensitivity of this response supports the prediction that trabecular bone adapts dynamically to the orientation of peak compressive forces.}, Doi = {10.1242/jeb.01971}, Key = {fds337889} } @article{fds337891, Author = {Pontzer, H}, Title = {A new model predicting locomotor cost from limb length via force production.}, Journal = {The Journal of experimental biology}, Volume = {208}, Number = {Pt 8}, Pages = {1513-1524}, Year = {2005}, Month = {April}, url = {http://dx.doi.org/10.1242/jeb.01549}, Abstract = {Notably absent from the existing literature is an explicit biomechanical model linking limb design to the energy cost of locomotion, COL. Here, I present a simple model that predicts the rate of force production necessary to support the body and swing the limb during walking and running as a function of speed, limb length, limb proportion, excursion angle and stride frequency. The estimated rate of force production is then used to predict COL via this model following previous studies that have linked COL to force production. To test this model, oxygen consumption and kinematics were measured in nine human subjects while walking and running on a treadmill at range of speeds. Following the model, limb length, speed, excursion angle and stride frequency were used to predict the rate of force production both to support the body's center of mass and to swing the limb. Model-predicted COL was significantly correlated with observed COL, performing as well or better than contact time and Froude number as a predictor of COL for running and walking, respectively. Furthermore, the model presented here predicts relationships between COL, kinematic variables and body size that are supported by published reduced-gravity experiments and scaling studies. Results suggest the model is useful for predicting COL from anatomical and kinematic variables, and may be useful in intra- and inter-specific studies of locomotor anatomy and performance.}, Doi = {10.1242/jeb.01549}, Key = {fds337891} } @article{fds337896, Author = {Pontzer, H and Wrangham, RW}, Title = {Climbing and the daily energy cost of locomotion in wild chimpanzees: implications for hominoid locomotor evolution.}, Journal = {Journal of human evolution}, Volume = {46}, Number = {3}, Pages = {317-335}, Year = {2004}, Month = {March}, url = {http://dx.doi.org/10.1016/j.jhevol.2003.12.006}, Abstract = {As noted by previous researchers, the chimpanzee postcranial anatomy reflects a compromise between the competing demands of arboreal and terrestrial locomotion. In this study, we measured the distance climbed and walked per day in a population of wild chimpanzees and used published equations to calculate the relative daily energy costs. Results were used to test hypotheses regarding the arboreal-terrestrial tradeoff in chimpanzee anatomy, specifically whether arboreal adaptations serve to minimize daily locomotor energy costs by decreasing the energy spent climbing. Our results show that chimpanzees spend approximately ten-times more energy per day on terrestrial travel than on vertical climbing, a figure inconsistent with minimizing energy costs in our model. This suggests non-energetic factors, such as avoiding falls from the canopy, may be the primary forces maintaining energetically costly climbing adaptations. These analyses are relevant to anatomical comparisons with living and extinct hominoids.}, Doi = {10.1016/j.jhevol.2003.12.006}, Key = {fds337896} } %% Papers Presented/Symposia/Abstracts @article{fds376281, Author = {McGrosky, A and Swanson, ZS and Rimbach, R and Bethancourt, H and Ndiema, E and Nzunza, R and Braun, DR and Rosinger, AY and Pontzer, H}, Title = {Total daily energy expenditure and elevated water turnover in a small-scale semi-nomadic pastoralist society from Northern Kenya.}, Journal = {Annals of human biology}, Volume = {51}, Number = {1}, Pages = {2310724}, Year = {2024}, Month = {February}, url = {http://dx.doi.org/10.1080/03014460.2024.2310724}, Abstract = {<h4>Background</h4>Pastoralists live in challenging environments, which may be accompanied by unique activity, energy, and water requirements.<h4>Aim</h4>Few studies have examined whether the demands of pastoralism contribute to differences in total energy expenditure (TEE) and water turnover (WT) compared to other lifestyles.<h4>Subjects and methods</h4>Accelerometer-derived physical activity, doubly labelled water-derived TEE and WT, and anthropometric data were collected for 34 semi-nomadic Daasanach adults from three northern Kenyan communities with different levels of pastoralist activity. Daasanach TEEs and WTs were compared to those of other small-scale and industrialised populations.<h4>Results</h4>When modelled as a function of fat-free-mass, fat-mass, age, and sex, TEE did not differ between Daasanach communities. Daasanach TEE (1564-4172 kcal/day) was not significantly correlated with activity and 91% of TEEs were within the range expected for individuals from comparison populations. Mean WT did not differ between Daasanach communities; Daasanach absolute (7.54 litres/day men; 7.46 litres/day women), mass-adjusted, and TEE-adjusted WT was higher than most populations worldwide.<h4>Conclusions</h4>The similar mass-adjusted TEE of Daasanach and industrialised populations supports the hypothesis that habitual TEE is constrained, with physically demanding lifestyles necessitating trade-offs in energy allocation. Elevated WT in the absence of elevated TEE likely reflects a demanding active lifestyle in a hot, arid climate.}, Doi = {10.1080/03014460.2024.2310724}, Key = {fds376281} } @article{fds355703, Author = {Ocobock, C and Soppela, P and Turunen, M and Stenbäck, V and Herzig, K-H and Rimbach, R and Pontzer, H}, Title = {Reindeer herders from subarctic Finland exhibit high total energy expenditure and low energy intake during the autumn herd roundup.}, Journal = {American journal of human biology : the official journal of the Human Biology Council}, Volume = {34}, Number = {4}, Pages = {e23676}, Year = {2022}, Month = {April}, url = {http://dx.doi.org/10.1002/ajhb.23676}, Abstract = {<h4>Objective</h4>High levels of total energy expenditure (TEE, kcal/day) have been documented among numerous human populations such as tropical climate horticulturalists and high-altitude agriculturalists. However, less work has been conducted among highly physically active cold climate populations.<h4>Methods</h4>In October 2018, TEE was measured using the doubly labeled water (TEE<sub>DLW</sub> , N = 10) and flex-heart rate methods (TEE<sub>HR</sub> , N = 24) for 6-14 days among reindeer herders (20-62 years) in northern Finland during an especially physically demanding, but not seasonally representative, period of the year for herders-the annual reindeer herd roundup. Self-reported dietary intake was also collected during TEE measurement periods. TEE was then compared to that of hunter gatherer, farming, and market economies.<h4>Results</h4>During the herd roundup, herders expended a mean of 4183 ± 949 kcal/day as measured by the DLW method, which was not significantly different from TEE<sub>HR</sub> . Mean caloric intake was 1718 ± 709 kcal/day, and was significantly lower than TEE<sub>DLW</sub> and TEE<sub>HR</sub> (p < .001). Herder TEE<sub>DLW</sub> was significantly higher than that of hunter gatherer (p = .0014) and market (p < .0014) economy populations; however, herder TEE<sub>DLW</sub> was not different from that of farming populations (p = .91).<h4>Conclusion</h4>High TEE and low caloric intake among herders reflect the extreme demands placed on herders during the annual herd round up. Although TEE<sub>DLW</sub> was similar between cold climate herders and hot climate farming populations, there are likely differences in how that TEE is comprised, reflecting the local ecologies of these populations.}, Doi = {10.1002/ajhb.23676}, Key = {fds355703} } @article{fds355699, Author = {Pontzer, H}, Title = {External Energy Exploitation and the Shared Evolutionary Roots of Climate Change and Chronic Disease}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {174}, Pages = {85-86}, Year = {2021}, Key = {fds355699} } @article{fds355700, Author = {Klasson, C and Sadhir, S and Pontzer, H}, Title = {Daily Physical Activity is Associated with Suppressed Immune Activity in US Adults}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {174}, Pages = {56-56}, Year = {2021}, Key = {fds355700} } @article{fds355701, Author = {Swanson, ZS and Bethancourt, H and Saunders, J and Nzunza, R and Ndiema, E and Braun, D and Rosinger, AY and Pontzer, H}, Title = {Distinct patterns of early childhood growth represent variation in life history strategy among Daasanach pastoralists living in Northern Kenya}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {174}, Pages = {101-102}, Year = {2021}, Key = {fds355701} } @article{fds355702, Author = {Sadhir, S and Pontzer, H}, Title = {Interbirth interval and age at first reproduction in populations with disparate energy status}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {174}, Pages = {91-91}, Year = {2021}, Key = {fds355702} } @article{fds355704, Author = {Rimbach, R and Pontzer, H}, Title = {Effects of physical activity and relatedness on metabolic phenotype in ring-tailed lemurs}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {174}, Pages = {90-90}, Year = {2021}, Key = {fds355704} } @article{fds350298, Author = {Bethancourt, H and Swanson, Z and Huanca, T and Conde, E and Saunders, J and Dhanasekar, S and Young, S and Nzunza, R and Pontzer, H and Rosinger, A}, Title = {Prevalence and predictors of dehydration across distinct water insecure contexts: The Water Insecurity, Stress, and Hydration (WISH) study among Tsimane' in lowland Bolivia and Daasanach in northern Kenya}, Journal = {AMERICAN JOURNAL OF HUMAN BIOLOGY}, Volume = {32}, Pages = {1 pages}, Publisher = {WILEY}, Year = {2020}, Month = {April}, Key = {fds350298} } @article{fds350299, Author = {Swanson, ZS and Bethancourt, H and Saunders, J and Dhanasekar, S and Nzunza, R and Rosinger, AY and Pontzer, H}, Title = {The effect of lifestyle variation on health and life history in Daasanach pastoralists of Northern Kenya}, Journal = {AMERICAN JOURNAL OF HUMAN BIOLOGY}, Volume = {32}, Pages = {1 pages}, Publisher = {WILEY}, Year = {2020}, Month = {April}, Key = {fds350299} } @article{fds350301, Author = {Swanson, ZS and Bethancourt, H and Saunders, J and Nzunza, R and Rosinger, AY and Pontzer, H}, Title = {Distinct early growth trajectory among Daasanach pastoralists of Northern Kenya}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {278-278}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350301} } @article{fds350302, Author = {Rimbach, R and Pontzer, H}, Title = {Follow my lead: energy expenditures in utero resemble maternal allometry in humans and chimpanzees}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {235-235}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350302} } @article{fds350303, Author = {Urlacher, SS and Sharma, A and Gilbert, JA and Pontzer, H and Snodgrass, JJ and Gildner, TE and Madimenos, FC and Liebert, MA and Sugiyama, LS and Dugas, LR}, Title = {Childhood gut microbiome composition among the Amazonian Shuar: Testing links to changing diet, lifestyle, energy expenditure, and health}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {290-291}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350303} } @article{fds350304, Author = {Pontzer, H}, Title = {High energy apes on a hot planet: the challenge of fueling an increasingly energy hungry hominin}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {221-221}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350304} } @article{fds350305, Author = {Hora, M and Pontzer, H and Defrate, LE and Charles, HC and Sladek, V and Mcginnis, A}, Title = {Effect of gait and velocity on in-vivo tibial loading in humans}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {124-124}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350305} } @article{fds350306, Author = {Ford, LB and Bethancourt, H and Swanson, Z and Young, S and Nzunze, R and Pontzer, H and Rosinger, AY}, Title = {Human biology among daasanach pastoralists in northern kenya: Water insecurity, water borrowing, and psychosocial stress}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {88-88}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350306} } @article{fds350307, Author = {Kozma, EE and Morgan, DB and Sanz, CM and Pontzer, H}, Title = {Climbing and Canopy access in Human Foragers is not limited by Grip Strength or Endurance}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {148-148}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350307} } @article{fds350308, Author = {Saunders, J and Swanson, ZS and Bethancourt, H and Dhanasekar, S and Nzunza, R and Rosinger, AY and Pontzer, H}, Title = {Human Biology and the Koobi Fora Field School: New Work with the Daasanach, a Small-Scale Pastoralist Population}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {248-248}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350308} } @article{fds350309, Author = {Webb, NM and Harcourt-Smith, WEH and Pontzer, H and Haeusler, M and Grabowski, M}, Title = {How to make a bipedal primate: 1 part phylogeny, 2 parts selection and a pinch of body size}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {303-303}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350309} } @article{fds350310, Author = {Rosinger, AY and Bethancourt, H and Swanson, ZS and Saunders, J and Dhanasekar, S and Kenney, WL and Young, SL and Nzunza, R and Pontzer, H}, Title = {Dam health effects: Drinking water salinity is a key risk factor for hypertension and dilute urine among Daasanach pastoralists in Northern Kenya}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {171}, Pages = {239-239}, Publisher = {WILEY}, Year = {2020}, Month = {March}, Key = {fds350310} } @article{fds346489, Author = {Horiuchi, M and Kirihara, YH and Fukuoka, Y and Pontzer, H}, Title = {Sex Differences In Respiratory And Circulatory Cost And Arterial Oxygen Saturation During Hypoxic Walking}, Journal = {Medicine & Science in Sports & Exercise}, Volume = {51}, Number = {6S}, Pages = {458-458}, Publisher = {Ovid Technologies (Wolters Kluwer Health)}, Year = {2019}, Month = {June}, url = {http://dx.doi.org/10.1249/01.mss.0000561874.25337.90}, Doi = {10.1249/01.mss.0000561874.25337.90}, Key = {fds346489} } @article{fds337776, Author = {Ocobock, C and Overbeck, A and Carlson, C and Royer, C and Mervenne, A and Thurber, C and Dugas, LR and Carlson, B and Pontzer, H}, Title = {Sustained high levels of physical activity lead to improved performance among "Race Across the USA" athletes.}, Journal = {American journal of physical anthropology}, Volume = {168}, Number = {4}, Pages = {789-794}, Publisher = {WILEY}, Year = {2019}, Month = {April}, url = {http://dx.doi.org/10.1002/ajpa.23781}, Abstract = {<h4>Objective</h4>To investigate physiological and performance adaptations associated with extremely high daily sustained physical activity levels, we followed six runners participating in the 2015 Race Across the USA. Participants completed over 42.2 km a day for 140 days, covering nearly 5,000 km. This analysis examines the improvement in running speed and potential adaptation in mean submaximal heart rate (SHR) throughout the race.<h4>Methods</h4>Data were collected during three 1-week long periods corresponding to the race beginning, middle, and end and included heart rates (HRs), body mass, running distances and speeds. HR data were collected using ActiTrainer HR monitors. Running speeds and distances were also recorded throughout the entire race.<h4>Results</h4>Athletes ran significantly faster as the race progressed (p < .001), reducing their mean marathon time by over 63 min. Observed mean SHR during the middle of the race was significantly lower than at the beginning (p = .003); however, there was no significant difference between mean SHR at the middle and end of the race (p = .998).<h4>Conclusion</h4>These results indicate an early training effect in SHR during the first half of the race, which suggests that other physiological and biomechanical mechanisms were responsible for the continued improvement in running speed and adaptation to the high levels of sustained physical activity.}, Doi = {10.1002/ajpa.23781}, Key = {fds337776} } @article{fds342248, Author = {Hora, M and Pontzer, H and Sladek, V}, Title = {Persistence hunting in Levant: Both Neandertals and modern humans could run down a horse}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {168}, Pages = {107-107}, Publisher = {WILEY}, Year = {2019}, Month = {March}, Key = {fds342248} } @article{fds342249, Author = {Kozma, EE and Pontzer, H and Sanz, C and Morgan, D}, Title = {Arboreal Positional Behavior in Humans, Chimpanzees, and Gorillas}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {168}, Pages = {131-131}, Publisher = {WILEY}, Year = {2019}, Month = {March}, Key = {fds342249} } @article{fds342250, Author = {Swanson, ZS and Pontzer, H and Luke, A and Dugas, LR and Steiper, ME}, Title = {The effect of the alpha-actinin 3 (ACTN3) R577X polymorphism and mtDNA on energy expenditure in modern humans}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {168}, Pages = {242-243}, Publisher = {WILEY}, Year = {2019}, Month = {March}, Key = {fds342250} } @article{fds342251, Author = {Sayre, MK and Pontzer, H and Wood, BA and Alexander, GA and Raichlen, DA}, Title = {Influence of physical activity on aging and frailty in human foragers}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {168}, Pages = {217-217}, Publisher = {WILEY}, Year = {2019}, Month = {March}, Key = {fds342251} } @article{fds342252, Author = {Wood, BM and Harris, JA and Vashro, L and Sayre, MK and Raichlen, DA and Pontzer, H and Sancilio, A and Berbesque, JC and Crittenden, AN and Mabulla, AZP and Jones, JH and Cashdan, E}, Title = {Hadza Hunter-Gatherers Exhibit Gender Differences in Space Use and Spatial Cognition Consistent with the Ecology of Male and Female Targeted Foods}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {168}, Pages = {273-274}, Publisher = {WILEY}, Year = {2019}, Month = {March}, Key = {fds342252} } @article{fds342253, Author = {Pontzer, H and Brown, MH and Raichlen, DA and Wood, BM and Luke, A and Dugas, LR and Ross, SR}, Title = {Water throughput in humans and apes}, Journal = {AMERICAN JOURNAL OF HUMAN BIOLOGY}, Volume = {31}, Number = {2}, Pages = {1 pages}, Publisher = {WILEY}, Year = {2019}, Month = {March}, Key = {fds342253} } @article{fds342254, Author = {Urlacher, SS and Snodgrass, JJ and Dugas, LR and Madimenos, FC and Sugiyama, LS and Pontzer, H}, Title = {The energetic ecology of childhood: Tradeoffs in energy allocation and the impact of market integration on ontogeny and health}, Journal = {AMERICAN JOURNAL OF HUMAN BIOLOGY}, Volume = {31}, Number = {2}, Pages = {1 pages}, Publisher = {WILEY}, Year = {2019}, Month = {March}, Key = {fds342254} } @article{fds342255, Author = {Levy, SB and Sancilio, A and Christopher, L and Madimenos, FC and Urlacher, SS and Snodgrass, JJ and Sugiyama, LS and Pontzer, H and Bribiescas, RG}, Title = {An assessment of urinary triiodothyronine (T3) levels as a biomarker of thyroid hormone action: preliminary data from the Shuar Health and Life History Project}, Journal = {AMERICAN JOURNAL OF HUMAN BIOLOGY}, Volume = {31}, Number = {2}, Pages = {1 pages}, Publisher = {WILEY}, Year = {2019}, Month = {March}, Key = {fds342255} } @article{fds342256, Author = {Machanda, Z and Brazeau, N and Castillo, E and Otarola-Castillo, E and Pontzer, H and Emery Thompson and M and Muller, M and Wrangham, R}, Title = {MUSCULOSKELETAL GROWTH IN WILD CHIMPANZEES WITH IMPLICATIONS FOR SOCIAL BEHAVIOR}, Journal = {AMERICAN JOURNAL OF PRIMATOLOGY}, Volume = {80}, Pages = {1 pages}, Publisher = {WILEY}, Year = {2018}, Month = {December}, Key = {fds342256} } @article{fds342259, Author = {Willis, EA and Saint-Maurice, PF and Pontzer, H and Matthews, CE}, Title = {Is More Physical Activity Always Better? Constrained vs Additive Total Energy Expenditure Models.}, Journal = {MEDICINE AND SCIENCE IN SPORTS AND EXERCISE}, Volume = {50}, Number = {5}, Pages = {841-841}, Publisher = {LIPPINCOTT WILLIAMS & WILKINS}, Year = {2018}, Month = {May}, Key = {fds342259} } @article{fds337759, Author = {Eyre, J and Pontzer, H}, Title = {The Effect of bi-iliac breadth on thermoregulation during running}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {165}, Pages = {80-81}, Publisher = {WILEY}, Year = {2018}, Month = {April}, Key = {fds337759} } @article{fds337757, Author = {Castillo, ER and Pontzer, H}, Title = {Locomotor-respiratory dynamics and gait frequency tuning in humans}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {165}, Pages = {43-44}, Publisher = {WILEY}, Year = {2018}, Month = {April}, Key = {fds337757} } @article{fds337758, Author = {Urlacher, SS and Snodgrass, JJ and Dugas, LR and Sugiyama, LS and Pontzer, H}, Title = {Direct measures of total and resting energy expenditure among Shuar forager-horticulturalist children: Evolutionary and epidemiological implications}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {165}, Pages = {281-281}, Publisher = {WILEY}, Year = {2018}, Month = {April}, Key = {fds337758} } @article{fds337760, Author = {Swanson, ZS and Pontzer, H and Luke, A and Dugas, LR and Steiper, ME}, Title = {The effect of the angiotensin-converting enzyme (ACE) I/D polymorphism on energy expenditure in modern humans}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {165}, Pages = {268-268}, Publisher = {WILEY}, Year = {2018}, Month = {April}, Key = {fds337760} } @article{fds337761, Author = {Raichlen, DA and Hamilton, MT and Harris, JA and Hsu, C-H and Keadle, SK and Klimentidis, YC and Marx, TJ and Matthews, CE and Pontzer, H and Sayre, MK and Wood, BM and Zderic, TW and Alexander, GE}, Title = {Fractal patterns of physical activity in hunter-gatherers suggest universal scaling of daily movement in humans}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {165}, Pages = {218-219}, Publisher = {WILEY}, Year = {2018}, Month = {April}, Key = {fds337761} } @article{fds337767, Author = {Urlacher, SS and Snodgrass, JJ and Kramer, KL and Konecna, M and Pontzer, H and Sugiyama, LS}, Title = {Objectively Measured Childhood Physical Activity among Small-scale Populations}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {389-389}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337767} } @article{fds337768, Author = {Schneider, AL and Burghardt, NS and Pontzer, H}, Title = {Reduced Immune Investment with Energy Stress: Evidence from a Mouse Model}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {349-349}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337768} } @article{fds337769, Author = {Otarola-Castillo, ER and Castillo, ER and Hora, M and Torquato, MG and Warrener, AG and Pontzer, H}, Title = {walkR: A Software Package to Analyze the Biomechanics of Human Locomotion}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {306-306}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337769} } @article{fds337770, Author = {Ramirez, KR and Pontzer, H}, Title = {Intrinsic Manual Proportions affect the Biomechanics of Suspension}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {326-326}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337770} } @article{fds337771, Author = {Kozma, EE and Webb, NM and Harcourt-Smith, WEH and Raichlen, DA and D'Aout, K and Brown, MH and Finestone, E and Ross, SR and Aerts, P and Pontzer, H}, Title = {Mechanics of Hip Extension Characterize Arboreal-Terrestrial Trade-offs in Hominin Evolution}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {251-251}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337771} } @article{fds337772, Author = {Swanson, ZS and Webb, NM and Pontzer, H and Desilva, JM and Harcourt-Smith, WEH}, Title = {Finite Element Modeling of Talar Loading in Modern Humans with Application to the Hominin Fossil Record}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {374-375}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337772} } @article{fds337773, Author = {Pontzer, H}, Title = {How Much Food do Animals Need to Walk, Run, and Climb? This Much}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {320-320}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337773} } @article{fds337774, Author = {Raichlen, DA and Pontzer, H and Harris, JA and Zderic, TW and Hamilton, MT and Wood, BM}, Title = {Objectively measured physical activity in a hunting and gathering population}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {326-326}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337774} } @article{fds337775, Author = {Lieberman, DE and Barak, MM and Rolian, CP and Raichlen, DA and Pontzer, H}, Title = {Testing hypotheses about hominin locomotor evolution using models not analogies}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {162}, Pages = {262-263}, Publisher = {WILEY}, Year = {2017}, Month = {April}, Key = {fds337775} } @article{fds337777, Author = {Gagnon, C and Steiper, M and Pontzer, H}, Title = {Body mass index varies with event distances among elite runners but not swimmers}, Journal = {AMERICAN JOURNAL OF HUMAN BIOLOGY}, Volume = {29}, Number = {2}, Pages = {2 pages}, Publisher = {WILEY}, Year = {2017}, Month = {March}, Key = {fds337777} } @article{fds337791, Author = {Edwards, W and Pontzer, H and Lonsdorf, E}, Title = {Energy expenditure and physical activity levels in captive tufted capuchins (Cebus apella)}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {159}, Pages = {136-136}, Publisher = {WILEY-BLACKWELL}, Year = {2016}, Month = {March}, Key = {fds337791} } @article{fds337792, Author = {Kozma, EE and Raichlen, DA and Wood, BM and Pontzer, H}, Title = {Determinants of Energetic Costs of Climbing in Humans}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {56}, Pages = {E116-E116}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2016}, Month = {March}, Key = {fds337792} } @article{fds337793, Author = {Kozma, EE and Raichlen, DA and Wood, BM and Pontzer, H}, Title = {Energetics and Muscle Use of Human Climbing}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {159}, Pages = {196-196}, Publisher = {WILEY-BLACKWELL}, Year = {2016}, Month = {March}, Key = {fds337793} } @article{fds337794, Author = {Pontzer, H and Raichlen, DA and Harris, JA and Wood, BM}, Title = {Energetics and Economics of Foraging in Humans and other Apes}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {159}, Pages = {255-255}, Publisher = {WILEY-BLACKWELL}, Year = {2016}, Month = {March}, Key = {fds337794} } @article{fds337795, Author = {Thurber, C and Carlson, B and Ocobock, C and Dugas, L and Pontzer, H}, Title = {Metabolic Limits and Adaptation in Humans: Daily Energy Expenditure in Race Across the USA Athletes}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {159}, Pages = {314-315}, Publisher = {WILEY-BLACKWELL}, Year = {2016}, Month = {March}, Key = {fds337795} } @article{fds337796, Author = {Finestone, EM and Brown, MH and Ross, SR and Pontzer, H}, Title = {Videographic analysis of kinematics in great apes: To what extent are gait and posture conserved?}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {159}, Pages = {143-143}, Publisher = {WILEY-BLACKWELL}, Year = {2016}, Month = {March}, Key = {fds337796} } @article{fds337788, Author = {Thurber, C and Carlson, B and Ocobock, C and Dugas, L and Pontzer, H}, Title = {Metabolic limits and adaptation in humans: Daily energy expenditure in Race Across the USA athletes.}, Journal = {AMERICAN JOURNAL OF HUMAN BIOLOGY}, Volume = {28}, Number = {2}, Pages = {298-298}, Publisher = {WILEY-BLACKWELL}, Year = {2016}, Month = {March}, Key = {fds337788} } @article{fds337789, Author = {Laird, MF and Pontzer, H}, Title = {Gape cycle kinematic variance and occlusal topography in modern humans}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {159}, Pages = {200-200}, Publisher = {WILEY-BLACKWELL}, Year = {2016}, Month = {March}, Key = {fds337789} } @article{fds337790, Author = {Raichlen, DA and Pontzer, H and Harris, JA and Zderic, TW and Hamilton, MT and Wood, BM}, Title = {Sitting, squatting, and the evolution of human inactivity}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {159}, Pages = {261-262}, Publisher = {WILEY-BLACKWELL}, Year = {2016}, Month = {March}, Key = {fds337790} } @article{fds337803, Author = {Pontzer, H and Brown, MH and Dunsworth, HM and Ross, SR}, Title = {Humans, the high-energy ape: hominoid energetics and life history evolution}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {156}, Pages = {255-255}, Publisher = {WILEY-BLACKWELL}, Year = {2015}, Month = {March}, Key = {fds337803} } @article{fds337804, Author = {Trumble, BC and Cummings, D and Beheim, B and Stieglitz, J and Yetish, G and Pontzer, H and Kaplan, H and Gurven, M}, Title = {Energetic costs of testosterone: higher testosterone is associated with greater lean muscle mass and total energetic expenditure among Tsimane forager-horticulturalists}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {156}, Pages = {307-308}, Publisher = {WILEY-BLACKWELL}, Year = {2015}, Month = {March}, Key = {fds337804} } @article{fds337805, Author = {Ramirez, KR and Pontzer, H}, Title = {Estimates of fossil hominin quadriceps physiological cross sectional area from patellar dimensions}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {156}, Pages = {261-261}, Publisher = {WILEY-BLACKWELL}, Year = {2015}, Month = {March}, Key = {fds337805} } @article{fds337806, Author = {Machanda, Z and Brazeau, NF and Castillo, E and Otarola-Castillo, E and Pontzer, H and Thompson, ME and Muller, M and Wrangham, RW}, Title = {Musculoskeletal growth patterns in wild chimpanzees (Pan troglodytes)}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {156}, Pages = {209-209}, Publisher = {WILEY-BLACKWELL}, Year = {2015}, Month = {March}, Key = {fds337806} } @article{fds337807, Author = {Laird, MF and Pontzer, H and Vogel, ER}, Title = {Chewing efficiency variation with food material properties and masticatory morphology in humans}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {156}, Pages = {197-197}, Publisher = {WILEY-BLACKWELL}, Year = {2015}, Month = {March}, Key = {fds337807} } @article{fds337813, Author = {Kozma, EE and Pontzer, H and Webb, N and Harcourt-Smith, W}, Title = {Hamstrings, moment arms, and gait mechanics in early hominins}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {153}, Pages = {160-160}, Publisher = {WILEY-BLACKWELL}, Year = {2014}, Month = {March}, Key = {fds337813} } @article{fds337814, Author = {Glasgow, AM and Pontzer, H}, Title = {Effects of honey consumption and latitude on hunter-gatherer nutritional profiles}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {153}, Pages = {125-125}, Publisher = {WILEY-BLACKWELL}, Year = {2014}, Month = {March}, Key = {fds337814} } @article{fds337815, Author = {Thomas, OO and Harcourt-Smith, WEH and Pontzer, H}, Title = {Exploring the relationship between anthropoid cuboid morphology and expressed locomotor behavior}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {153}, Pages = {253-253}, Publisher = {WILEY-BLACKWELL}, Year = {2014}, Month = {March}, Key = {fds337815} } @article{fds337816, Author = {Darr, MR and Pontzer, H and Raichlen, DA}, Title = {A comparison of mediolateral ground forces in humans and chimpanzees}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {153}, Pages = {102-102}, Publisher = {WILEY-BLACKWELL}, Year = {2014}, Month = {March}, Key = {fds337816} } @article{fds337812, Author = {Pontzer, H and Raichlen, DA and Wood, BM and Racette, SB and Delany, JP and Mabulla, AZP and Marlowe, FW and Isler, K and Dunsworth, HM and Schroepfer-Walker, KK and Hare, B and Shumaker, RW and Lonsdorf, EV and Ross, SR}, Title = {Daily water turn over in humans, apes, and fossil hominins}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {153}, Pages = {210-210}, Publisher = {WILEY-BLACKWELL}, Year = {2014}, Month = {March}, Key = {fds337812} } @article{fds337822, Author = {Ocobock, C and Pontzer, H and Gookin, J}, Title = {Measuring and predicting daily energy expenditure of highly active humans in natural environments.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {150}, Pages = {210-210}, Publisher = {WILEY-BLACKWELL}, Year = {2013}, Month = {January}, Key = {fds337822} } @article{fds337823, Author = {Webb, NM and Harcourt-Smith, WEH and Pontzer, H}, Title = {An analysis of the Ardipithecus ramidus pelvis reconstruction using 3D geometric morphometric techniques.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {150}, Pages = {287-287}, Publisher = {WILEY-BLACKWELL}, Year = {2013}, Month = {January}, Key = {fds337823} } @article{fds337824, Author = {Laird, MF and Pontzer, H}, Title = {Occlusal surfaces and chewing efficiency in modern humans.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {150}, Pages = {176-177}, Publisher = {WILEY-BLACKWELL}, Year = {2013}, Month = {January}, Key = {fds337824} } @article{fds337825, Author = {Darr, MR and Pontzer, H and Warrener, A}, Title = {The bicondylar angle in modern humans and its relationship to joint stresses and locomotor economy}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {150}, Pages = {108-108}, Publisher = {WILEY-BLACKWELL}, Year = {2013}, Month = {January}, Key = {fds337825} } @article{fds337826, Author = {Green, SA and Pontzer, H}, Title = {Comparing forelimb skeletal anatomy in gray squirrels and primates}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {150}, Pages = {136-136}, Publisher = {WILEY-BLACKWELL}, Year = {2013}, Month = {January}, Key = {fds337826} } @article{fds337827, Author = {Pontzer, H and Raichlen, DA and Gordon, AD and Schroepfer, KK and Hare, B and Dunsworth, HM and Wood, BM and Irwin, MT and Shumaker, RW and Lonsdorf, EV and Ross, SR}, Title = {Primate energy expenditure and life history.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {150}, Pages = {223-223}, Publisher = {WILEY-BLACKWELL}, Year = {2013}, Month = {January}, Key = {fds337827} } @article{fds337833, Author = {Raichlen, DA and Pontzer, H and Wood, BM and Mabulla, AZP and Marlowe, FW}, Title = {Aerobic activity in the Hadza hunter-foragers of Tanzania}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {147}, Pages = {243-243}, Publisher = {WILEY-BLACKWELL}, Year = {2012}, Month = {January}, Key = {fds337833} } @article{fds337834, Author = {Pontzer, H}, Title = {Relating foraging ecology to locomotor economy and limb length in living apes and fossil hominins}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {147}, Pages = {239-239}, Publisher = {WILEY-BLACKWELL}, Year = {2012}, Month = {January}, Key = {fds337834} } @article{fds337835, Author = {Laird, MF and Pontzer, H}, Title = {Biomechanical relationships between chewing efficiency and dental morphology in modern humans.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {147}, Pages = {188-188}, Publisher = {WILEY-BLACKWELL}, Year = {2012}, Month = {January}, Key = {fds337835} } @article{fds337836, Author = {Schroepfer, KK and Hare, B and Pontzer, H}, Title = {Energy expenditure in semi free-ranging chimpanzees measured using doubly labeled water.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {147}, Pages = {263-263}, Publisher = {WILEY-BLACKWELL}, Year = {2012}, Month = {January}, Key = {fds337836} } @article{fds337840, Author = {Maki, JM and Pontzer, H}, Title = {The relative contributions of the body and the throwing arm to throwing velocity in softball and baseball players}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {51}, Pages = {E223-E223}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2011}, Month = {March}, Key = {fds337840} } @article{fds337841, Author = {Ocobock, C and Pontzer, H and Gookin, J and Baynes, S}, Title = {A new multivariate model for predicting daily energy expenditure in active human populations}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {51}, Pages = {E102-E102}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2011}, Month = {March}, Key = {fds337841} } @article{fds337842, Author = {Dunsworth, H and Warrener, A and Pontzer, H}, Title = {LIFE HISTORY JUST ISN'T HIP: HUMAN EVOLUTION WITHOUT AN 'OBSTETRIC DILEMMA'}, Journal = {JOURNAL OF VERTEBRATE PALEONTOLOGY}, Volume = {31}, Pages = {102-102}, Publisher = {SOC VERTEBRATE PALEONTOLOGY}, Year = {2011}, Month = {January}, Key = {fds337842} } @article{fds337843, Author = {Wood, BM and Raichlen, DA and Pontzer, H and Jones, JH and Mabulla, AZP and Marlowe, FW}, Title = {Keeping their friends close? Contrasting models of social association in Hadza hunter-gatherers}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {144}, Pages = {314-314}, Publisher = {WILEY-BLACKWELL}, Year = {2011}, Month = {January}, Key = {fds337843} } @article{fds337844, Author = {Ocobock, C and Pontzer, H and Gookin, J and Baynes, S}, Title = {Daily energy expenditure in highly active humans in a natural temperate environment.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {144}, Pages = {227-227}, Publisher = {WILEY-BLACKWELL}, Year = {2011}, Month = {January}, Key = {fds337844} } @article{fds337845, Author = {Raichlen, DA and Wood, BM and Pontzer, H and Mabulla, AZP and Marlowe, FW}, Title = {Levy walks in hunter-gatherers: when are random walks an optimal search strategy?}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {144}, Pages = {246-247}, Publisher = {WILEY-BLACKWELL}, Year = {2011}, Month = {January}, Key = {fds337845} } @article{fds337846, Author = {Dunsworth, H and Pontzer, H and Deacon, T}, Title = {Energetics-not pelvic constraints-determine human gestation length and altriciality}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {144}, Pages = {129-129}, Publisher = {WILEY-BLACKWELL}, Year = {2011}, Month = {January}, Key = {fds337846} } @article{fds337847, Author = {Pontzer, H and Raichlen, DA and Wood, BM and Mabulla, AZP and Marlowe, FW}, Title = {Hadza forager energetics and the evolution of the human metabolic strategy.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Volume = {144}, Pages = {242-242}, Publisher = {WILEY-BLACKWELL}, Year = {2011}, Month = {January}, Key = {fds337847} } @article{fds337851, Author = {Joganic, JL and Pontzer, H and Verrelli, BC}, Title = {The hungry brain: An assessment of liver size correlation with brain size as it relates to energy storage trade-offs across primate evolution.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {135-135}, Publisher = {WILEY-LISS}, Year = {2010}, Month = {January}, Key = {fds337851} } @article{fds337852, Author = {Pontzer, H and Raichlen, DA and Wood, BM}, Title = {Hominoid daily energy expenditure and the Human Paradox.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {191-191}, Publisher = {WILEY-LISS}, Year = {2010}, Month = {January}, Key = {fds337852} } @article{fds337853, Author = {Ocobock, C and Pontzer, H and Erez, T and Maki, J}, Title = {Climatic and physiological constraints on human body size and shape.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {180-180}, Publisher = {WILEY-LISS}, Year = {2010}, Month = {January}, Key = {fds337853} } @article{fds337856, Author = {Ocobock, CJ and Pontzer, H and Maki, J}, Title = {Modification of limb inertial properties leads to persistent changes in neural control of walking in humans}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {49}, Pages = {E283-E283}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2009}, Month = {February}, Key = {fds337856} } @article{fds337857, Author = {Pontzer, H and Kamilar, J}, Title = {Greater Ranging Associated with Greater Reproductive Investment in Mammals: A New Perspective on Foraging Economics}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {49}, Pages = {E137-E137}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2009}, Month = {February}, Key = {fds337857} } @article{fds337859, Author = {Pontzer, H and Ocobock, C and Shumaker, RW and Raichlen, DA}, Title = {Daily energy expenditure in orangutans measured using doubly labeled water}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {213-213}, Publisher = {WILEY-LISS}, Year = {2009}, Month = {January}, Key = {fds337859} } @article{fds337860, Author = {Erez, T and Smart, WD and Pontzer, H}, Title = {A new computational method for simulation and optimization of hominin gait}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {125-125}, Publisher = {WILEY-LISS}, Year = {2009}, Month = {January}, Key = {fds337860} } @article{fds337861, Author = {Foster, AD and Raichlen, DA and Pontzer, H and Sockol, MD}, Title = {Muscle force production during bent-knee, bent-hip walking in humans.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {129-129}, Publisher = {WILEY-LISS}, Year = {2009}, Month = {January}, Key = {fds337861} } @article{fds337862, Author = {Ocobock, T and Pontzer, H and Atkinson, E and Shumaker, RW and Wittman, AB}, Title = {Locomotor developmental timing in humans and other apes}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {201-201}, Publisher = {WILEY-LISS}, Year = {2009}, Month = {January}, Key = {fds337862} } @article{fds337863, Author = {Wittman, AB and Cowgill, LW and Pontzer, H and Ocobock, C}, Title = {Waddling and toddling: biomechanical effects of an immature gait.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {93-93}, Publisher = {WILEY-LISS}, Year = {2009}, Month = {January}, Key = {fds337863} } @article{fds337867, Author = {Raichlen, D and Pontzer, H and Sockol, M}, Title = {Are Two Legs Better than Four? Comparative Biomechanics & the Evolution of Human Walking & Running}, Journal = {FASEB JOURNAL}, Volume = {22}, Pages = {1 pages}, Publisher = {FEDERATION AMER SOC EXP BIOL}, Year = {2008}, Month = {April}, Key = {fds337867} } @article{fds337869, Author = {Wittman, AB and Pontzer, H}, Title = {The effect of pelvic dimorphism on locomotor cost: are women less efficient than men?}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {69-69}, Publisher = {WILEY-LISS}, Year = {2008}, Month = {January}, Key = {fds337869} } @article{fds337870, Author = {Pontzer, H and Raichlen, DA and Sockol, MD}, Title = {Endurance versus efficiency in humans and chimpanzees: a new look at the old problem of becoming bipedal}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {173-173}, Publisher = {WILEY-LISS}, Year = {2008}, Month = {January}, Key = {fds337870} } @article{fds337871, Author = {Maki, J and Pontzer, H}, Title = {A predictive model for hominid lower limb length based on mean annual temperature, day range and body mass.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {147-147}, Publisher = {WILEY-LISS}, Year = {2008}, Month = {January}, Key = {fds337871} } @article{fds337872, Author = {Orkin, JD and Pontzer, H}, Title = {Is primate-like grasping needed for fine branch feeding? Terminal branch use in eastern gray squirrels, Sciurus carolinensis.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {166-166}, Publisher = {WILEY-LISS}, Year = {2008}, Month = {January}, Key = {fds337872} } @article{fds337873, Author = {Watsa, M and Pontzer, HD}, Title = {Does increased ranging effort lead to fewer wasted menstrual cycles?}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {218-218}, Publisher = {WILEY-LISS}, Year = {2008}, Month = {January}, Key = {fds337873} } @article{fds337875, Author = {Pontzer, H and Raichlen, DA and Sockol, MD}, Title = {Locomotor energetics in chimpanzees, humans, and extinct hominins: Contributions of muscular and skeletal anatomy}, Journal = {JOURNAL OF MORPHOLOGY}, Volume = {268}, Number = {12}, Pages = {1118-1118}, Publisher = {WILEY-LISS}, Year = {2007}, Month = {December}, Key = {fds337875} } @article{fds337880, Author = {Raichlen, DA and Pontzer, H and Sockol, MD}, Title = {Joint kinetics in chimpanzees and other mammals: Are large bodied primates unique?}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {194-194}, Publisher = {WILEY-LISS}, Year = {2007}, Month = {January}, Key = {fds337880} } @article{fds337881, Author = {Pontzer, H and Raichlen, DA and Sockol, MD}, Title = {Contributions of muscular and skeletal morphology to locomotor performance: How much can bones tell us about locomotion?}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {191-191}, Publisher = {WILEY-LISS}, Year = {2007}, Month = {January}, Key = {fds337881} } @article{fds337882, Author = {Pontzer, H and Raichlen, DA and Sockol, MD}, Title = {Niche expansion of a cryptic primate, Callimico goeldii, during polyspecific associations.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {191-191}, Publisher = {WILEY-LISS}, Year = {2007}, Month = {January}, Key = {fds337882} } @article{fds337883, Author = {Raichlen, DA and Pontzer, H and Sockol, MD}, Title = {The energetics of quadrupedal and bipedal locomotion in chimpanzees}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {46}, Pages = {E114-E114}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2006}, Month = {December}, Key = {fds337883} } @article{fds337884, Author = {Pontzer, H and Raichlen, DA and Lieberman, DE}, Title = {Is arm swing active or passive during human walking and running?}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {46}, Pages = {E112-E112}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2006}, Month = {December}, Key = {fds337884} } @article{fds337887, Author = {Pontzer, H}, Title = {Locomotor energetics and ranging ecology of fossil hominids.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {148-148}, Publisher = {WILEY-LISS}, Year = {2006}, Month = {January}, Key = {fds337887} } @article{fds337888, Author = {Raichlen, DA and Pontzer, H and Sockol, MD}, Title = {Energetics of chimpanzee locomotion: Force production during bipedal and quadrupedal walking.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {150-150}, Publisher = {WILEY-LISS}, Year = {2006}, Month = {January}, Key = {fds337888} } @article{fds337890, Author = {Pontzer, H}, Title = {Linking locomotor energetics to limb design in terrestrial animals}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {45}, Number = {6}, Pages = {1057-1057}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2005}, Month = {December}, Key = {fds337890} } @article{fds337892, Author = {Pontzer, H and Lieberman, DE and Momin, EN and Devlin, MJ and Polk, JD and Hallgrimsson, B and Cooper, DML}, Title = {The effect of a "bent-knee" gait on trabecular orientation: an experiment test of Wolff's Law}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {167-167}, Publisher = {WILEY-LISS}, Year = {2005}, Month = {January}, Key = {fds337892} } @article{fds337893, Author = {Lieberman, DE and Pontzer, H and Cutright-Smith, E and Raichlen, D}, Title = {Why is the human gluteus so maximus?}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {138-138}, Publisher = {WILEY-LISS}, Year = {2005}, Month = {January}, Key = {fds337893} } @article{fds337894, Author = {Pontzer, H}, Title = {The effect of limb length on locomotor performance}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {44}, Number = {6}, Pages = {623-623}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2004}, Month = {December}, Key = {fds337894} } @article{fds337895, Author = {Lieberman, DE and Pontzer, H and Momin, E and Devlin, M and Polk, J and Hallgrimsson, B and Cooper, D}, Title = {An experimental test of Wolffs law in the knee}, Journal = {INTEGRATIVE AND COMPARATIVE BIOLOGY}, Volume = {44}, Number = {6}, Pages = {592-592}, Publisher = {OXFORD UNIV PRESS INC}, Year = {2004}, Month = {December}, Key = {fds337895} } @article{fds337897, Author = {Pontzer, H}, Title = {The effect of leg length on human locomotor performance}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {161-162}, Publisher = {WILEY-BLACKWELL}, Year = {2004}, Month = {January}, Key = {fds337897} } @article{fds337898, Author = {Wrangham, RW and Pontzer, H}, Title = {Chimpanzee juveniles constrain their mothers' gregariousness}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {211-212}, Publisher = {WILEY-BLACKWELL}, Year = {2004}, Month = {January}, Key = {fds337898} } @article{fds337899, Author = {Devlin, MJ and Pontzer, H and Lieberman, DE and Polk, JP}, Title = {Trabecular bone orientation in flexed versus extended postures in guinea fowl: A test of Wolffs Law.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {88-89}, Publisher = {WILEY-LISS}, Year = {2003}, Month = {January}, Key = {fds337899} } @article{fds337900, Author = {Pontzer, H}, Title = {Climbing behavior and locomotor energetics in wild chimpanzees: Implications for hominin locomotor evolution.}, Journal = {AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY}, Pages = {170-170}, Publisher = {WILEY-LISS}, Year = {2003}, Month = {January}, Key = {fds337900} } | ||
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