Post-Reproductive Lifespan in Humans: Cultural Artifact, Widespread Primate Trait or Unique Adaptation?

Daniel Levitis, University of California, Berkeley
Laurie Bingaman Lackey, International Species Information System (ISIS)

A significant biological and anthropological literature has arisen attempting to explain why women have evolved the ability to survive for decades after they become infertile. Some have argued that post-reproductive survival is just an artifact of modern human habits. Others have argued that it is a general mammalian trait, and humans are therefore unexceptional. Others offer functional evolutionary arguments. In this paper we present data on post-reproductive survival in 67 species of captive primates, three human hunter-gather populations and three industrialized countries. These captive primates benefit from medical care and nutritionally planned diets; human hunter-gatherers do not. Our data indicate that human females' post-reproductive survival greatly exceeds that of every other primate, but that culture and phylogeny also play important roles. In supporting all three hypotheses, we argue that they function on separate levels of analysis and should be seen as complimentary, not alternative explanations.