An Ecosystem approach to Hominin Environments in the East African plio-Pleistocene

对人类适应和进化的研究与人类进化所处环境的知识密切相关。这些环境具有必须理解的时空维度，以便回答有关环境变化如何影响早期人类进化的关键问题。根据一种假说，200万至300万年前的全球气候变化是非洲哺乳动物进化辐射的主要原因，其中包括我们的直系祖先。气候很可能确实在某种程度上影响了人类的进化，但具体是如何以及何时发生的仍然存在争议。一些研究人员认为，经验证据尚未证明气候变化在非洲哺乳动物进化中的作用。必须仔细检查和控制化石记录中的保存偏差、不同的数据收集方法以及非洲不同化石地点的不同时间和空间分辨率，以便严格检验气候变化假说。该项目将测试全球气候记录与500万至100万年前非洲陆地生态系统中哺乳动物动物群变化之间的联系。重点将放在肯尼亚和埃塞俄比亚的图尔卡纳盆地以及埃塞俄比亚北部的哈达尔-迪基卡地区，这两个地区是人类祖先(人)化石的两个主要来源，以及其他哺乳动物的丰富记录。图尔卡纳盆地古生态数据库将由现有的独立数据集、博物馆藏品和使用选定地层层段标准化采样的新野外倡议汇编而成。与哈达尔-迪基卡地区的比较将从现有的哈达尔动物数据库和实地收集的新数据中得出。由此产生的信息将展示东非早期原始人居住的环境以及这些环境如何随时间变化，早期原始人与哪些哺乳动物物种关系最密切，以及全球气候记录如何与不同空间和时间尺度上的陆地动物群和考古变化相关。这项研究的信息和解释将通过科学期刊、公共科学教育媒体和互联网向公众提供。

The study of human adaptation and evolution is intimately tied to knowledge of the environments in which humans evolved. These environments have space-time dimensions that must be understood in order to answer key questions about how environmental change affected early human evolution. According to one hypothesis, global climatic change between 2 and 3 million years ago was responsible for a major evolutionary radiation of mammals in Africa that included our direct ancestors. It is likely that climate did affect human evolution in some way, but exactly how and when this happened remains controversial. Some researchers believe that empirical evidence has not yet demonstrated the role of climate change in African mammal evolution. Preservation biases in the fossil record, differing data-collection methods, and varying levels of chronological and spatial resolution across fossil localities in Africa must be carefully examined and controlled in order to rigorously test the climate change hypothesis. This project will test the linkage between the global climatic record and changes in mammal faunas from terrestrial ecosystems in Africa between 5 and 1 million years ago. The focus will be on the Turkana Basin of Kenya and Ethiopia and the Hadar-Dikika region of northern Ethiopia, two of the major sources of fossils of human ancestors (hominins) as well as a rich record of other mammals. The Turkana Basin Paleoecology Database will be assembled from existing separate datasets, museum collections, and new field initiatives that use standardized sampling of selected stratigraphic intervals. Comparisons with the Hadar-Dikika region will draw from the existing Hadar Faunal Database and new data collected in the field. The resulting information will demonstrate what environments were inhabited by early hominins in East Africa and how these environments changed through time, what mammal species early hominins were most closely associated with, and how global climate records correlate with terrestrial faunal and archeological change at different spatial and temporal scales. Information and interpretations derived from this research will be made available to the public via scientific journals, public science education media, and the internet.