Doctoral Dissertation Improvement: Reconstructing Seasonality, Woody Cover, and Habitat Heterogeneity in Modern and Ancient East African Environments with Stable Isotopes.

人类谱系在上新世-更新世（约300万至100万年前）的进化历史通常与气候和生态变化有关。这一时期在东非的化石和考古记录中有很好的代表性，包括人类进化中一些最重要的进化和适应性转变。虽然全球气候历史相对较好地了解，但确定当地环境变化对于解释这些发展的原因至关重要。降雨的季节性和局部尺度的变化，植被在整个空间可能代表的进化变化的根本驱动力，但是，很少有经验记录可用于评估这种看法。 这项研究的第一个目的是由博士生斯科特布卢门塔尔，在托马斯普卢默博士的监督下，在纽约市立大学，是收集土壤和哺乳动物的牙齿从现代乌干达环境中测试的假设，降雨季节性和植被覆盖的变化内和栖息地之间可以确定与稳定同位素。采样将在乌干达的国家公园和保护区进行，包括从森林到草原的各种环境。这将为重建化石记录中的这些环境条件提供一个模板。本研究的第二个目的是使用稳定同位素分析的化石土壤和牙齿从上新世更新世沉积的霍马半岛，肯尼亚西部，产生一个当地的环境记录，通过时间，并评估假设连接当地的环境变化与人类进化。这个研究不足但化石和人工制品丰富的地区为人类进化提供了地理，地质和生态学上的独特视角。 拟议的研究将促进与两个东非国家的研究人员和机构的国际合作。与乌干达野生动物管理局的合作将为制定项目提供机会，目的是在现有的养护管理技术中增加生态监测和稳定同位素分析。该项目还将有助于本科实习生的教育，除了加强合作PI的研究生培训。

The evolutionary history of the human lineage during the Plio-Pleistocene (~3 to 1 million years ago) is often linked to climatic and ecological change. This time period is well represented in the fossil and archaeological records in East Africa and includes some of the most important evolutionary and adaptive shifts in human evolution. While global climate history is relatively well understood, identifying local environmental change is critical for explaining why these developments occurred. Rainfall seasonality and local-scale variation in vegetation across space may represent fundamental drivers of evolutionary change; however, few empirical records are available to evaluate this perception. The first aim of this study by doctoral student Scott Blumenthal, under the supervision of Dr. Thomas Plummer at CUNY, is to collect soils and mammal teeth from modern Ugandan environments to test the hypothesis that variation in rainfall seasonality and vegetation cover within and between habitats can be identified with stable isotopes. Sampling will be conducted in national parks and reserves in Uganda, including a wide range of environments, from forests to grasslands. This will provide a template for reconstructing these environmental conditions in the fossil record. The second aim of this study is to use stable isotope analysis of fossil soils and teeth from Plio-Pleistocene deposits of the Homa Peninsula, western Kenya, to produce a local environmental record through time, and evaluate hypotheses linking local environmental variability with human evolution. This under-studied but fossil- and artifact-rich region provides a geographically, geologically, and ecologically unique perspective on hominin evolution. The proposed research will foster international collaborations with researchers and institutions in two East African countries. Collaboration with the Ugandan Wildlife Authority will provide opportunities to develop projects with the aim of adding ecological monitoring with stable isotope analysis to existing conservation management techniques. This project also will contribute to the education of an undergraduate intern, in addition to enhancing the graduate training of the co-PI.