Eve Boyle

EVE K. BOYLE, then a graduate student at George Washington University, Washington, DC, was awarded funding in April 2018 to aid research on ‘Beyond the Skull: Identifying Potential Correlates of Diet in the Primate Torso,’ supervised by Dr. Bernard Wood. Torso differences between Australopithecus and Homo are often claimed to reflect a reduction in gut size following an increase in diet quality in the latter genus. This hypothesis emerges from the fact that animals that primarily eat green plants exhibit larger guts than animals that rely on prey, and the assumption that torso form reflects accommodations for differently sized guts. However, recent studies show that other factors might influence primate torso morphology, and the existence and nature of any relationships between the torso and diet have not been demonstrated in living primates. This research uses phylogenetic generalized least squares (PGLS) regressions to test hypotheses relating diet to anthropoid primate torso morphology. Linear measurements were collected across a broad sample of primates, and integrated with data on gut size, feeding observations, locomotion, and body size from the literature. Results suggest that there is no dietary effect on the primate torso after controlling for body size, phylogeny, and locomotion. This research provides little support for the practice of inferring diet from fossil hominin torso remains.