Evolutionary processes occurring within the last 3 million years of the hominin lineage have been intimately associated with diet. Dietary factors hypothesized to have played critical roles in the niche partitioning between australopithecines, paranthropines, and early Homo include variable contributions of seeds, tubers, ripe or unripe fruit, pith, and animal flesh. Current approaches, however, lack the necessary resolution for differentiating the dietary contribution of these items within fossil species. Isotopic approaches represent one methodology with the potential of quantitatively estimating the contribution of individual food stuffs within a given dietary niche. As the tissues of an organism are constructed from dietary components ingested from the environment, the isotopic composition of the individual reflect these inputs. However, to interpret tissue level isotopic variation in relation to individual diet, one must understand the underlying isotopic variability within the lived environment.
The goal of this project is to utilize compound specific isotopic analyses of individual amino acids to reveal how isotopic variability within the diet of chimpanzees is consumed, metabolized, and deposited within the hard tissues. Incorporating elements of primatology, biogeochemistry, and nutritional science this project will examine amino acid delta13C and delta15N variability within the environment and the subsequent physiological routing from diet to hair, bone and teeth of modern chimpanzees in Kibale National Forest, Uganda. Intellectual merit: These analyses represent a novel and significant approach to improve our understanding of isotopic variability within modern East African C3 ecosystems and chimpanzee physiology. Additionally, they will provide the groundwork necessary for high-resolution dietary reconstruction from fossil remains of our earliest hominin ancestors. Broader impacts: The ability to quantify past consumption and thereby elucidate the role of foods over the course of human evolution is critically important for making informed decisions about how humans should healthfully, sustainably, and ethically consume into the future. This research will contribute to the doctoral dissertation and academic training of a graduate student.
