Browsing by Author "Stoinski, Tara S"

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Open Access
Low demographic variability in wild primate populations: fitness impacts of variation, covariation, and serial correlation in vital rates.
(Am Nat, 2011-01) Morris, William F; Altmann, Jeanne; Brockman, Diane K; Cords, Marina; Fedigan, Linda M; Pusey, Anne E; Stoinski, Tara S; Bronikowski, Anne M; Alberts, Susan C; Strier, Karen B
In a stochastic environment, long-term fitness can be influenced by variation, covariation, and serial correlation in vital rates (survival and fertility). Yet no study of an animal population has parsed the contributions of these three aspects of variability to long-term fitness. We do so using a unique database that includes complete life-history information for wild-living individuals of seven primate species that have been the subjects of long-term (22-45 years) behavioral studies. Overall, the estimated levels of vital rate variation had only minor effects on long-term fitness, and the effects of vital rate covariation and serial correlation were even weaker. To explore why, we compared estimated variances of adult survival in primates with values for other vertebrates in the literature and found that adult survival is significantly less variable in primates than it is in the other vertebrates. Finally, we tested the prediction that adult survival, because it more strongly influences fitness in a constant environment, will be less variable than newborn survival, and we found only mixed support for the prediction. Our results suggest that wild primates may be buffered against detrimental fitness effects of environmental stochasticity by their highly developed cognitive abilities, social networks, and broad, flexible diets.
Open Access
The emergence of longevous populations.
(Proc Natl Acad Sci U S A, 2016-11-29) Colchero, Fernando; Rau, Roland; Jones, Owen R; Barthold, Julia A; Conde, Dalia A; Lenart, Adam; Nemeth, Laszlo; Scheuerlein, Alexander; Schoeley, Jonas; Torres, Catalina; Zarulli, Virginia; Altmann, Jeanne; Brockman, Diane K; Bronikowski, Anne M; Fedigan, Linda M; Pusey, Anne E; Stoinski, Tara S; Strier, Karen B; Baudisch, Annette; Alberts, Susan C; Vaupel, James W
The human lifespan has traversed a long evolutionary and historical path, from short-lived primate ancestors to contemporary Japan, Sweden, and other longevity frontrunners. Analyzing this trajectory is crucial for understanding biological and sociocultural processes that determine the span of life. Here we reveal a fundamental regularity. Two straight lines describe the joint rise of life expectancy and lifespan equality: one for primates and the second one over the full range of human experience from average lifespans as low as 2 y during mortality crises to more than 87 y for Japanese women today. Across the primate order and across human populations, the lives of females tend to be longer and less variable than the lives of males, suggesting deep evolutionary roots to the male disadvantage. Our findings cast fresh light on primate evolution and human history, opening directions for research on inequality, sociality, and aging.