Eocene-Oligocene Primate Evolution and Climate Change in the Fayum Depression, Northern Egypt

现在研究灵长类动物进化的学者们普遍认为，现存的猴子、猿和人类（类人猿）最后的共同祖先生活在始新世晚期的非洲，大约在4500万到3400万年前。记录灵长类动物进化史上这一关键阶段的主要化石证据来自埃及北部法耶姆洼地暴露的沉积层，这些沉积层的年龄在3700万年到2800万年之间。过去的研究已经揭示了2900万到3400万年前生活在这一地区的类人猿灵长类动物的多种辐射的证据；最近在该地区一个更古老的3700万年前的遗址发现了类人猿和其他灵长类动物的化石，现在为古生物学家提供了一个前所未有的800万年的灵长类动物和非灵长类哺乳动物在北非这一地区的进化记录。在2008年、2009年和2010年的三个野外季节中，法尤姆地区的古生物学工作将有助于揭示对类人猿早期进化史的重要新见解，包括哺乳动物时代对地球气候最显著的变化之一的影响——南极冰川的迅速开始，以及与之相关的全球冷却阶段，大约始于3400万年前的始新世-渐新世边界。一个由脊椎动物古生物学家、地质学家、古植物学家和地球化学家组成的熟练团队已经集合起来，收集和分析整个演替过程中的脊椎动物化石、植物化石和岩石样本，作为研究始新世-渐新世边界气候事件之前、期间和之后的环境变化、灵长类动物和非灵长类动物的进化和适应的一种手段。稳定同位素数据将从化石标本中提取，以确定地点和重建古环境。因此，我们的团队不仅将像过去一样收集新的脊椎动物化石材料，而且重要的是，我们的目标是将化石遗址置于一个年代久远的框架中，以便在当地和全球环境变化的背景下评估生物进化和灭绝的模式。恢复和分析化石证据，记录我们与类人猿和其他灵长类动物共同的进化史，是科学界和公众的极大兴趣。尽管经过多年的古生物学研究，许多关键问题仍未得到解答；例如，地理、板块构造、气候变化、灭绝和竞争在塑造我们的类人猿祖先的古代进化史中所起的作用仍在积极讨论中。这项研究将为一些年轻的博士生提供古生物学领域的培训，其中包括在体质人类学，特别是古人类学中代表性不足的群体的成员。这项研究还将使美国和埃及的研究人员作为国际合作的一部分共同努力，为美国和埃及的学生和教育工作者提供新的机会和资源。

There is now broad agreement among students of primate evolution that the last common ancestor of the living monkeys, apes, and humans (Anthropoidea) lived in Africa during the later part of the Eocene epoch, between about 45 and 34 million years ago. The primary fossil evidence documenting this critical phase in primate evolutionary history comes from sedimentary deposits exposed in the Fayum Depression, northern Egypt, which are 37 to 28 million years in age. Past work has revealed evidence for a diverse radiation of anthropoid primates that lived in this area 29 to 34 million years ago; the recent discovery of fossil anthropoids and other primates at a much older, 37 million-year-old, site in the area has now provided paleontologists with an unprecedented 8-million-year-long record of primate and non-primate mammalian evolution in this part of northern Africa. Over the course of three field seasons (in 2008, 2009, 2010) paleontological work in the Fayum area will help to reveal important new insights into the early evolutionary history of Anthropoidea, including the impact of one of the most dramatic changes to Earth climate during the Age of Mammals -- the rapid onset of Antarctic glaciation, and associated global cooling phase, which began about 34 million years ago at the Eocene-Oligocene boundary. A skilled team of vertebrate paleontologists, geologists, paleobotanists, and geochemists has been assembled to collect and analyze vertebrate fossils, plant fossils, and rock samples throughout this succession as a means for studying environmental change and primate and non-primate evolution and adaptation before, during, and after the climatic events at the Eocene-Oligocene boundary. Stable isotope data will be extracted from fossil specimens in order to date localities and reconstruct paleoenvironments. As such, our team will not only collect new vertebrate fossil material as in years past, but importantly also aims to place fossil sites into a well-dated framework so that patterns of biotic evolution and extinction can be evaluated within the context of both local and global environmental change.Recovery and analysis of the fossil evidence that documents our shared evolutionary history with anthropoids and other primates is of great interest to the scientific community and the general public. Despite many years of paleontological research, a number of key questions remain unanswered; for instance, the roles that geography, plate tectonics, climate change, extinction, and competition have played in shaping our anthropoid ancestors' ancient evolutionary history continue to be actively debated. This research will provide paleontological field training for a number of young Ph.D. students, including members of groups that are underrepresented in physical anthropology and particularly paleoanthropology. This research will also allow American and Egyptian researchers to work together as part of an international collaboration that will provide new opportunities and resources for students and educators in both the U.S.A. and Egypt.