ABSTRACT

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.

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