Department of Biology, Duke University, Durham, United States; Lewis-Sigler Institute for Integrative Genomics, Carl Icahn Laboratory, Princeton University, Princeton, United States; Department of Ecology and Evolution, Princeton University, Princeton, United States
Department of Biology, Duke University, Durham, United States; Department of Anthropology, University of Texas at San Antonio, San Antonio, United States
Tawni N Voyles
Department of Evolutionary Anthropology, Duke University, Durham, United States
Department of Evolutionary Anthropology, Duke University, Durham, United States; Department of Biology, Duke University, Durham, United States; Duke Population Research Institute, Duke University, Durham, United States; Canadian Institute for Advanced Research, Toronto, Canada
Aging, for virtually all life, is inescapable. However, within populations, biological aging rates vary. Understanding sources of variation in this process is central to understanding the biodemography of natural populations. We constructed a DNA methylation-based age predictor for an intensively studied wild baboon population in Kenya. Consistent with findings in humans, the resulting ‘epigenetic clock’ closely tracks chronological age, but individuals are predicted to be somewhat older or younger than their known ages. Surprisingly, these deviations are not explained by the strongest predictors of lifespan in this population, early adversity and social integration. Instead, they are best predicted by male dominance rank: high-ranking males are predicted to be older than their true ages, and epigenetic age tracks changes in rank over time. Our results argue that achieving high rank for male baboons – the best predictor of reproductive success – imposes costs consistent with a ‘live fast, die young’ life-history strategy.
