As a mathematical tool designed to decompose population growth rates into age-specific demographic components, LTREs are typically used to aid conservation efforts for endangered species. With the largest high-quality dataset assembled to date on fertility and mortality among human subsistence societies and chimpanzees, we employ life table response experiments to quantify the importance of particular age classes for driving population growth and to identify the vital rates that best explain the divergence of human and chimpanzee life histories. Whereas many contemporary small-scale societies are growing rapidly, documented chimpanzee populations are typically shrinking, though favorable conditions promote increase in some wild groups. In doing so, we also characterize the tradeoffs that may have shaped human life history evolution. Here, we evaluate human uniqueness by identifying the vital rates that drive life history variation among populations within each species as well as between species. Despite this variation, primates are generally viewed as falling along the slow end of a slow-fast life history continuum due to delayed maturity, longevity and relatively low fertility, with humans at the slowest end of primates. In addition, mortality profiles of modern hunter-gatherers are closer to chimpanzees than they are to today’s low-mortality post-industrialized populations, but there is much variation among human and chimpanzee life histories. Human fertility declines well in advance of survival, whereas reproductive and actuarial senescence appear to occur together in chimpanzees. Human fertility schedules are similar to chimpanzees except for menopause, which appears unique among mammals, apart from a few toothed whale species. Humans and chimpanzees, whose recent common ancestor dates to 4–8 million years ago, share behavioral adaptations and life history traits that distinguish them from other primates.
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