This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This research will analyze serum samples and associated morphometric measurements previously collected from well characterized populations of wild baboons in the Awash National Park, Ethiopia. These sera samples were collected over fourteen field seasons and include the entire spectrum of ages within the populations. Using enzyme immunoassay techniques this study will quantify levels of seven growth- and inflammation-related hormones and proteins to test hypotheses regarding: 1) the endocrine correlates of divergent growth trajectories in two species of baboons, including different patterns of post-prime changes in body mass; 2) the hormonal underpinnings of unique aspects of the hybrid growth trajectory; and 3) how wild baboon populations compare to captive baboon populations with regard to the hormonal correlates of growth and maturation. Intellectual Merit: The results of this study will shed light on the physiological mechanisms underlying differences in growth and adult size. They will also provide a basic framework for understanding how shifts in timing and duration of developmental events can be accomplished on a mechanical level. This addresses important questions regarding plasticity and development and speaks to the evolution of growth, development, and senescence thus furthering our understanding of the evolution of ontogeny in primates. Broader Impacts: This project will employ one professional, full-time technician, and a number of undergraduate and graduate students will participate as research interns during the duration of the research. Further, a number of aspects of this research project will be integrated into undergraduate and graduate courses thus contributing to students' academic development and training.
