Doctoral Dissertation Research: Do social environments influence the timing of male maturation in a close human relative?

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Developmental plasticity allows organisms to become adults that are well-adapted to the environment they live in. This is how genetically similar individuals may develop different traits when exposed to different environments during their developmental period. In primates, and other social animals, the social environment is believed to be an especially important developmental influence. Male primates are particularly interesting subjects for developmental plasticity research due to their long developmental periods, the high variance in how many offspring they produce, and the variety of tactics they use to compete for mating opportunities. In many primate species, however, even basic male developmental patterns are not well understood. In this research project, the investigators explore if and how social environments affect the behavioral, hormonal, and physical development in males of an ape species. The diversity of social environments along with the extreme physical characteristics of these male apes makes them an excellent species in which to conduct this research. In addition to contributing to our understanding of the role that social environments play in determining adult characteristics in a close human relative, this project will make significant contributions to capacity building, education, and training. Limited information is currently available regarding how male primate developmental patterns are shaped by developmental conditions. This research project explores how social environments influence the behavioral, physiological, and morphological trajectories of male gorillas. The chosen species is particularly well suited for this research due to its highly variable social environments and anecdotal reports of considerable developmental plasticity across its long growth trajectories. This project collects non-invasive behavioral and photogrammetry data, along with testosterone and DHEA-S metabolites obtained from urine and fecal samples, on ~120 habituated male gorillas living in social groups of varying demographic compositions. Newly obtained information is combined with available longitudinal data to generate hormonal, physical, and behavioral profiles from infancy through adulthood. These data are used to better understand the order in which developmental changes occur, the nature and degree of inter-individual developmental variation, and the role(s) that social environments may play in predicting such variation. 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.