Doctoral Dissertation Research: Isotopic and proteomic signatures of diet

现代人类和相关物种独特的饮食适应性反映了适应性和文化复杂性，这是人类谱系进化成功的关键。这个项目将专注于改进我们对一种化学方法的理解，这种方法通常用于预测古人类饮食中肉类的数量。研究结果将有助于解释人类及其祖先的饮食变化。该项目还将在公共卫生领域有更广泛的应用，包括测量肉类品质、适口性、成分和营养。该项目将继续通过史密森学会和其他当地机构为STEM推广活动做出贡献。这项工作将有助于培养一名研究生和两名来自STEM领域代表性不足群体的本科生。稳定同位素研究是了解饮食适应的重要工具。物质和动物遗骸在许多化学元素中留下了明显的同位素特征，氮同位素比率特别能说明肉类的摄入量。先前的研究表明，骨骼中的氮同位素比率大致可以追踪生物体的营养水平。这一见解已被应用于考古记录，以预测人类的营养水平。虽然经常使用，但由于对某些生物和文化介导的过程（如腐烂和烹饪）中氮同位素行为的理解有限，这种替代方法容易出现并发症。因此，目前不可能在可比的情况下准确地重建饮食。因此，该项目将完善我们对这些过程中氮同位素分拨机制的理解，为基于同位素混合模型的饮食重建提供可测试的预测，并将同位素混合模型应用于尼安德特人饮食重建的案例研究问题。总之，这些结果将使我们了解饮食是如何适应动态的社会和生态环境的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.