Collaborative Research: The influence of climate and tectonics on Miocene ecosystems and faunal evolution in the East African Rift, Kenya

在地球科学和生命科学的交叉点上，一个长期存在的问题是，气候和构造在生命的进化中扮演了什么角色，如果有的话？东非裂谷是研究地球过程对哺乳动物进化影响的最佳地点之一。在这里，该地区的地质和气候历史，包括作为人类摇篮的裂谷系统的形成，以一种独特的方式保存在沉积岩中。该团队将调查这些沉积物及其包含的化石，以深入了解古代气候和栖息地，这些气候和栖息地记录了过去2500万年中人类、他们的灵长类祖先和非洲哺乳动物的出现。我们的研究将探索肯尼亚图尔卡纳盆地构造、气候和哺乳动物进化之间的关系，采用综合野外、实验室和模型研究。新的和现有的数据将结合起来，研究裂谷发育、气候变化以及它们各自在植被和哺乳动物进化中的作用之间的联系。该团队将建立一个构造模型，重建东非这一地区过去2500万年的裂谷演化，并将构造模型与同等或更好分辨率的气候-植被模型相结合。独立的地质、地球化学、古生态学和古生物学数据将用于验证这些模型的输出，以区分构造和气候对图尔卡纳生态系统和哺乳动物进化的影响。该项目还将培训几名博士后学者、研究生和本科生，并为他们提供在肯尼亚进行实地工作的机会。该项目旨在测试以构造和气候对哺乳动物和晚新生代陆地生态系统进化的复杂相互作用问题为中心的多种假设。该团队设计了一种综合方法来探索大陆裂谷、全球和区域气候在图尔卡纳盆地2800万至500万年前灵长类动物和其他哺乳动物进化中的作用。一个时间依赖的、运动学的和动态的东非构造模型将被用来探索整个裂谷系统的演化。构造模型将与地球系统模型和动态植被模型相结合，以检验我们的假设。模型结果将与来自图尔卡纳盆地的新代理数据进行验证，这些数据包括岩石地层学、放射性测年、团块同位素测温、植物蜡生物标志物、牙釉质同位素、古植物学、牙齿微磨损和生态计量学，这些数据结合在一起，能够独立重建该地区的气候、构造和动物进化。我们的多学科、多机构项目包括培养下一代科学家的机会，包括培养3名研究生、4名博士后和至少11名本科生。我们更广泛的影响目标是招收和培养学生从事科学事业，特别是来自地球科学领域代表性不足的少数民族的学生。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。

A longstanding question at the intersection of Earth and Life sciences is what roles, if any, do climate and tectonics play in the evolution of life? The East African Rift is among the best places to study the influences of Earth processes on the evolution of mammals. Here the region’s geologic and climate histories, including the formation of the rift system that is the cradle of humankind, are preserved in sedimentary rocks in a unique way. The team will investigate these sediments, and the fossils they contain, to gain insight into ancient climate and habitats that record the emergence of humans, their primate ancestors, and African mammals over the last 25 million years. Our research will explore relationships between tectonics, climate, and mammal evolution in the Turkana Basin, Kenya using integrated field, laboratory, and modeling studies. New and existing data will be combined to study the links between rift development, climate change, and their respective roles in vegetation and mammal evolution. The team will produce a tectonic model that reconstructs rift evolution in this region of East Africa for the past 25 million years, and the tectonic model will be integrated with climate-vegetation models of equal or better resolution. Independent geological, geochemical, paleoecological, and paleontological data will be used to validate these model outputs to distinguish the influences of tectonics and climate on the evolution of Turkana ecosystems and mammals. The project will also train several postdoctoral scholars, graduate students, and undergraduate students, and provide them with the opportunity to conduct field work in Kenya. This project seeks to test multiple hypotheses centered on questions regarding the complex interplay of tectonics and climate on the evolution of mammals and late Cenozoic terrestrial ecosystems. The team have designed an integrated approach to explore the roles of continental rifting and global and regional climate on the evolution of primates and other mammals in the Turkana Basin from 28 to 5 million year ago. A time-dependent, kinematic and dynamic tectonic model for East Africa will be used to explore evolution of the entire Rift System. The tectonic model will be integrated with an Earth system model coupled to a dynamic vegetation model to test our hypotheses. The model outputs will be validated with new proxy data from the Turkana Basin that includes lithostratigraphy, radiometric dating, clumped isotope thermometry, plant wax biomarkers, enamel isotopes, paleobotany, dental microwear, and ecometrics, that taken together, enable independent reconstruction of the climate, tectonic, and faunal evolution in the region. Our multidisciplinary, multi-institutional project includes training opportunities for the next generation of scientists, including training of three graduate students, four postdocs, and at least 11 undergraduates. Our broader impacts objectives are to recruit and prepare students for careers in science, especially students from underrepresented minorities in the Earth Sciences.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.