Todd R. Yokley,

Research Interests:
Ecogeographic variation in human respiratory anatomy; Energetics of past human populations; Human and primate functional morphology

Research Summary:
Broadly speaking, I am interested in analyzing the functional significance of anatomical variation in recent humans in such a way that allows for a better understanding of the physiology, energetic budgets, and adaptive strategies of extinct human species. Currently, I am investigating morphological variation in the nasal passages of recent and fossil humans. While ecogeographic variation in external nasal morphology has been thoroughly investigated over the past century, the nasal passages have been largely ignored despite the fact that they play a more prominent role in the performance of the primary functions of the nose. The lack of work in this area is due primarily to the complexity of internal nasal anatomy and the inherent difficulty in measuring such structures. However, recent advances in 3-D imaging technology have allowed me to develop a method for measuring dimensions of the nasal passages (specifically, air volume and mucosal surface area) using clinical CT scans of living people. Furthermore, by systematically investigating the relationship between skeletal and soft-tissue nasal morphology on CT scans, I am able to estimate dimensions of the nasal passages of fossil humans even in the absence of internal soft-tissue structures and taphonomically fragile turbinate bones. The results of my research have revealed a strong clinal distribution in the surface-area-to-volume ratio of the nasal passages of recent and fossil humans that appears to be the result of selection for more efficient heat and moisture conservation or dissipation as necessitated by different environmental conditions.

My current research will provide the foundation for a long-term research program in human respiratory anatomy and physiology. In addition to continued research into ecogeographic patterns of human internal nasal morphology, I plan to take a more experimental approach in the future by concentrating on the functional significance of internal nasal variation (i.e., how variation in anatomy affects the ability to modify the temperature and moisture content of respired air). On the whole, this research will lead to a better understanding of how climatological pressures have shaped human evolution as well as provide insight into the functional and adaptive significance of the morphology of Neandertals and other fossil humans.

Representative Publications   (More Publications)   (search)

  1. Yokley,T.R. The Functional and Adaptive Significance of Anatomical Variation in Recent and Fossil Human Nasal Passages.  2006. (Ph.D. Dissertation, Duke University)  [abs]
  2. Yokley, T.R. & Churchill, S.E. "Archaic and modern human distal humeral morphology." Journal of Human Evolution 51 (2006): 603-616.  [abs]
  3. Yokley, T.R. "A reanalysis of Neandertal internal nasal morphology." Journal of Human Evolution  (Submitted, in revision).  [abs]
  4. Yokley, T.R. "Ecogeographic variation in human nasal passages." (2006). Paper presented at the 75th Annual Meeting of the American Association of Physical Anthropologists, March 10, 2006, Anchorage, AK (Abstract: Am. J. Phys. Anthropol. Suppl. 42, 191).  [abs]
  5. Yokley, T.R. & Franciscus, R.G. "Variation in nasal passage surface-area-to-volume ratios of recent and fossil humans." (2005). Paper presented at the 2005 Annual Meeting of the Paleoanthropology Society, April 5, 2005, Milwaukee, WI (Abstract: PaleoAnthropology 2005 PAS Abstracts Volume, A12).  [abs]
  6. Miller, S.F., Yokley, T.R., Churchill, S.E., Franciscus, R.G., Hublin, J.J., & Eaves-Johnson, K.L. "A new technique for reconstructing the vocal anatomy of fossil humans." (2003). Paper presented at the 72nd meeting of the American Association of Physical Anthropologists, April 26, 2003, Tempe, AZ (Abstract: Am. J. Phys. Anthropol. Suppl. 36, 151-152).  [abs]
  7. Yokley, T.R. & Hutchinson, V.T. "Refining character sets for hominin phylogenetic analysis." (2003). Paper presented at the 2003 Annual Meeting of the Paleoanthropology Society, April 22, 2003, Tempe, AZ.  [abs]

Education:


Contact Info: 

002 Biological Sciences Building | (919) 660-7395 | try@duke.edu

Curriculum Vitae