Publications [#43589] of Nancy L Barrickman

Book Sections/Chapters

1. van Schaik, C., Barrickman, N.L., Bastian, M., Krakauer, E., van Noordwijk, M, Primate life histories and the role of brains, in Evolution of Human Life History, edited by K. Hawkes and R. Paine (in press), SAR Press, Santa Fe, NM
   (last updated on 2006/01/08)

   Abstract:
   Primate life histories are among the slowest of all mammals, and those of great apes are the slowest among primates. Because humans show a further slowing down of some aspects of their life history, study of primate life histories is pertinent to the understanding of human life history. Slow life history affects behavior both directly and indirectly, by affecting the relative duration of components of the immature period. Among primates, slow life histories are characterized by a disproportional shortening of the relative duration of gestation, leading to increased vulnerability to infanticide by males. These direct and indirect effects on behavior may have selected for cognitively rich behavioral solutions. We also draw attention to the increasingly well-documented correlation between slow life histories and large brain size. While demographic models have been fairly successful in explaining life history variation across taxa, they ignore this correlation, which may explain the reduced growth and reproduction of some lineages. We explore several hypotheses developed to explain the correlation between brain size and life history, and suggest that these ideas can be integrated into a single framework. On the one hand, the development of larger adult brains inevitably imposes a developmental cost on the organism, usually in terms of a delay in maturity, which must be offset by fitness benefits, usually improved adult survival, and thus longer reproductive life. On the other hand, in species with slower life history selection often favors larger brain size. We examine the relationship between this approach and the main competing models to explain the evolution of human life histories (the Grandmother and the Embodied Capital hypotheses).