Doctoral Dissertation Research: Behavioral and physiological flexibility as mediators of fitness

Primates, including humans, have long lives and long times between generations, potentially limiting their ability to adapt to selective pressures that emerge quickly. Interactions between genetics and the environment that allow behavioral and physiological flexibility may therefore be particularly important in primates. This doctoral dissertation project characterizes individual behavioral and hormonal responses to acute environmental changes in a non-human primate species to examine how gene-environment interactions mediate health and reproductive fitness. The project advances fundamental understanding of adaptive processes and supports student training in biotechnological methods and public science engagement. Research linking individual variation in behavioral and hormonal responsivity to fitness-relevant measures requires rich, longitudinal datasets to support robust exploration. This study builds on an existing longitudinal (40 years) database, collecting new data on behavioral and ecological variables. Fecal samples will be collected to analyze glucocorticoids (stress hormones). Individual variability in stress response will be examined in relation to fitness (muscle mass and reproductive outcomes). GIS/remote sensing is used to assess ranging/resource use, and Bayesian linear mixed models are used to assess if variation in behavioral and hormonal responsivity is associated with individual characteristics—including age, sex, reproductive status, dominance, and early life experience—and longitudinal fitness-relevant markers of performance (i.e., relative muscle mass via urinary creatinine, lifetime reproductive success, reproductive output, female interbirth intervals). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.