FESD Type I: Earth System Dynamics and its Role in Human Evolution in Africa

该项目将收集和分析肯尼亚和埃塞俄比亚关键地区的湖泊沉积物钻芯记录，以极大地提高我们对人类进化的古环境和古气候背景的理解。了解气候/环境历史与人类进化之间的关系是广泛的科学和公共利益的持久挑战。关键问题包括：在人类进化的关键时期，气候和构造变化是如何相互作用的？是什么过程在地方到区域的尺度上调控了这段历史？当地的气候变化记录是否反映了全球的变化？气候和构造过程是如何以及何时结合起来影响早期人类的栖息地、资源和人口统计的？这些变化的条件与人类谱系中的进化过程和事件有关吗？对这种关系的研究跨越了地球科学、环境科学和人类学。我们将从湖泊沉积物中收集沉积物钻芯，将提供详细和高度分辨率的环境历史记录。通过数据收集和建模，我们旨在从根本上改变关于全球、区域和地方尺度的环境动态如何塑造人类进化史的争论。该项目将通过在埃塞俄比亚（N. Awash River和Chew Bahir地区）和肯尼亚（W. Turkana， Tugen Hills和肯尼亚南部裂谷/马加迪湖）的五个高优先区域钻取长岩心来获得连续的古环境记录，在这些地区，可以在含有化石和人工制品的同一盆地中通过重要的时间间隔收集高分辨率、连续的湖泊古气候记录。我们没有假设环境历史和进化之间存在联系，而是将本研究设计为一系列数据收集和建模练习，以明确测试有关环境和进化动力学的总体和局部假设。我们的高分辨率（百年-千年尺度）和可测定的地球化学、古生态和沉积学记录将允许在区域尺度上定量重建古降水、古温度、古水文和地貌演化。我们将使用高分辨率地层学、磁地层学和其他地质年代学技术，将这些记录与邻近的人类和其他脊椎动物化石、人工制品以及附近的海洋记录联系起来。我们将在人类进化的关键时期开发环境变化和生态系统响应的预测数值模型，并根据我们新的高分辨率记录对这些模型进行评估。这些实验将研究景观和气候变化在时间和空间尺度上如何影响关键生态系统资源的持久性和可预测性。它们将使我们能够评估气候阈值和环境突变的重要性，并更好地了解可能塑造人类进化记录的地球系统动力学。我们的建模将产生新的、可测试的人类进化/地球系统动力学假设，包括进化的古人类种群对其环境的可能反馈。我们的项目将创建一个关键的数据集，用于解决人类存在的基本问题。我们将为16名美国研究生、2名博士后和10名本科生提供培训和实习机会，并在项目的实地和初始核心描述阶段为非洲学生和专业参与者提供大量培训机会。我们还计划在非正式教育方面进行大量投资，通过3d视频项目和外联活动，我们将在钻井期间和之后与我们的三个博物馆合作伙伴（史密森学会、肯尼亚国家博物馆和埃塞俄比亚国家博物馆）协调。

This project will collect and analyze lake sediment drill core records from key localities in Kenya and Ethiopia to vastly improve our understanding of the paleoenvironmental and paleoclimatic context of human evolution. Understanding the relationship between climate/environmental history and human evolution is an enduring challenge of broad scientific and public interest. Key questions include: How did climate and tectonic change interact during critical intervals of human evolution? What processes regulated this history on local to regional scales? Do local records of climate change reflect global changes? How and when did climatic and tectonic processes combine to influence early human habitats, resources, and demography? Were these changing conditions related to evolutionary processes and events in the human lineage? Research on this relationship cuts across Earth, environmental and anthropological sciences. The sediment drill cores we will collect from lake deposits will provide detailed and highly resolved records of environmental history. Through data collection and modeling we aim to fundamentally transform the debate concerning how environmental dynamics at global, regional and local scales may have shaped human evolutionary history.The project will obtain continuous paleoenvironmental records by drilling long cores from five high-priority areas in Ethiopia (N. Awash River and Chew Bahir areas) and Kenya (W. Turkana, Tugen Hills and southern Kenya Rift/Lake Magadi) where highly-resolved, continuous lacustrine paleoclimate records can be collected through important time intervals in the same basins that contain fossils and artifacts. Rather than assume a linkage between environmental history and evolution, we designed this study as a series of data collection and modeling exercises to explicitly test overarching and local hypotheses about environmental and evolutionary dynamics. Our high-resolution (centennial-millennial scale) and datable geochemical, paleoecological and sedimentological records will allow quantitative reconstruction of paleoprecipitation, paleotemperature, paleohydrology and geomorphic evolution at a regional scale. We will correlate these records using high-resolution tephrostratigraphy, magnetostratigraphy and other geochronological techniques to adjacent exposures that contain hominin and other vertebrate fossils, and artifacts, as well as to nearby marine records. We will develop predictive numerical models of environmental change and ecosystem response during critical intervals of human evolution and evaluate these models against our new, high-resolution records. These experiments will examine how landscape and climate change across a hierarchy of temporal and spatial scales impacts the durability and predictability of critical ecosystem resources. They will allow us to evaluate the importance of climatic thresholds and abrupt environmental changes and better understand the earth system dynamics that might have shaped the record of human evolution. Our modeling will generate new, testable hypotheses of human evolution/Earth system dynamics, including possible feedbacks from evolving hominin populations to their environments. Our project will create a key data set for addressing fundamental, existential questions for humanity. We will provide training and internship opportunities for 16 American graduate students, 2 post-docs and 10 undergraduates, and numerous training opportunities for African student and professional participants during the field and initial core description phase of the project. We have also planned significant investment in informal education, through a 3-D video project and outreach activities we will coordinate with our three museum partners (Smithsonian Institution, National Museums of Kenya and Ethiopia), both during and following the drilling phase.