Older age becomes common late in human evolution
- *Department of Anthropology, University of Michigan, Ann Arbor, MI 48109-1092; and ‡Department of Anthropology, University of California, Riverside, CA 92521-0418
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Communicated by Ward H. Goodenough, University of Pennsylvania, Philadelphia, PA, May 27, 2004 (received for review October 28, 2003)
Abstract
Increased longevity, expressed as number of individuals surviving to older adulthood, represents one of the ways the human life history pattern differs from other primates. We believe it is a critical demographic factor in the development of human culture. Here, we examine when changes in longevity occurred by assessing the ratio of older to younger adults in four hominid dental samples from successive time periods, and by determining the significance of differences in these ratios. Younger and older adult status is assessed by wear seriation of each sample. Whereas there is significant increased longevity between all groups, indicating a trend of increased adult survivorship over the course of human evolution, there is a dramatic increase in longevity in the modern humans of the Early Upper Paleolithic. We believe that this great increase contributed to population expansions and cultural innovations associated with modernity.
