Doctoral Dissertation Research: Isotopic and proteomic signatures of diet

George Washington University, Washington DC

Investigators

Abstract

The unique dietary adaptations of modern humans and related species reflect adaptability and cultural complexity, keys to the evolutionary success of the human lineage. This project will focus on refining our understanding of a chemical method commonly used to predict the amount of meat in diets of hominins. The results will inform interpretations of dietary shifts in humans and their ancestors. This project will also have broader applications in public health, including measuring meat quality, palatability, composition, and nutrition. This project will continue to contribute to STEM outreach initiatives through the Smithsonian and other local institutions. The work will contribute to training a graduate student and two undergraduate students from underrepresented groups in STEM. Stable isotope research is an important tool at the forefront of efforts to understand dietary adaptations. Material and faunal remains leave distinct isotopic signatures across a number of chemical elements, with nitrogen isotope ratios being particularly informative about how much meat is consumed. Previous research has shown that nitrogen isotope ratios in bone roughly track the trophic level of an organism. This insight has been applied to the archaeological record to predict the trophic level of humans. Though often used, this proxy is subject to complications stemming from a limited understanding of nitrogen isotope behavior under certain biologically and culturally mediated processes like rotting and cooking. Thus, it is currently impossible to accurately reconstruct diets under comparable scenarios. Therefore, this project will refine our understanding of nitrogen isotope fractionation mechanisms in these processes, provide testable predictions for dietary reconstruction based on an isotope mixing model, and apply the isotope mixing model to a case study question in Neanderthal dietary reconstruction. Together, these results will inform our understanding of how diets have adapted in response to dynamic social and ecological environments. 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.