HRRBAA: Paleontology and paleoanthropology of a potential Late Miocene site in the Laikipia highlands

1160万年前至533万年前（晚中新世）是人类和猿类进化的一个重要转折点，人类、大猩猩和黑猩猩都起源于这一时期。 我们所知的非洲稀树大草原的动物群--以大象、斑马和多种羚羊为主--也是在这段环境变化的关键时期建立起来的，其特征是C4植被（主要是草）的扩张。尽管晚中新世在人类和哺乳动物进化中的重要性，但东非晚中新世的化石记录仅限于东非裂谷系（EARS）的少数几个地点。这个高风险的研究项目将通过开发新发现的化石遗址Tumbili Estate的科学潜力，提高我们对晚中新世人类和哺乳动物进化的理解，该遗址位于肯尼亚莱基皮亚县高地的EARS之外。该项目将为美国和肯尼亚的本科生和研究生提供研究经验，这将加强研究人员的渠道，并导致更多的全球参与的劳动力。通过我们与肯尼亚当地利益攸关方联盟莱基皮亚论坛的合作，该项目将提高社区成员对人类进化的理解，并使当地人民在其土地上进行的科学中有发言权。DNA证据已经确定，人类、大猩猩和黑猩猩的谱系起源于中新世晚期。然而，这些谱系起源的化石证据很少。中新世晚期已知的猿类化石是零碎的，化石和现代猿类之间的潜在联系在很大程度上是未知的。发现更多的猿类和/或人类化石（即，这一时期的化石是了解人类、大猩猩和黑猩猩谱系起源的关键。该研究项目将确认Tumbili Estate沉积物的年龄和范围，根据以前发现的化石，这些沉积物的年龄可能在9 - 10 Ma之间，并允许对附近地区进行调查以寻找其他地点。对Tumbili古环境的分析将提供有关C4植被扩张时间和非洲哺乳动物区系现代化的宝贵新数据。Tumbili位于EARS之外的高海拔高原上，这一事实将大大增加我们对晚中新世期间景观上栖息地的空间和海拔变化的理解。该奖项反映了NSF的法定使命，并被认为值得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来支持。

The period between 11.6 - 5.33 million years ago (the Late Miocene) was a major turning point in human and ape evolution, with the human, gorilla, and chimpanzee lineages all originating during this interval. The recognizable fauna of the African savanna as we know it - dominated by elephants, zebras, and many kinds of antelopes - was also established during this critical interval of environmental change, characterized by expanding C4 vegetation (predominantly grasses). Despite the importance of the Late Miocene in human and mammalian evolution, the fossil record from the Late Miocene in eastern Africa is restricted to only a handful of sites in the East African Rift System (EARS). This high-risk research project will improve our understanding of human and mammalian evolution in the Late Miocene by developing the scientific potential of a newly discovered fossil site called Tumbili Estate, located outside the EARS in the highlands of Laikipia County, Kenya. This project will provide research experience for American and Kenyan undergraduate and graduate students, which will bolster the researcher pipeline and lead to a more globally engaged workforce. Through our partnership with the Laikipia Forum, a consortium of local Kenyan stakeholders, this project will enhance the understanding of human evolution among community members, and give local people a voice in the science being conducted on their land. DNA evidence has firmly established that the human, gorilla and chimpanzee lineages originated during the Late Miocene. However, the fossil evidence for the origin of these lineages is meager. The known ape fossils from the Late Miocene are fragmentary, and the potential links between the fossils and the modern apes are largely unknown. The recovery of additional fossil ape and/or hominin (i.e., human ancestor) fossils from this time period is the key to understanding the origin of the hominin, gorilla, and chimpanzee lineages. This research project will confirm the age and extent of sediments at the Tumbili Estate, which likely date between 9 - 10 Ma based on fossils previously recovered, and also allow survey of nearby areas for additional sites. Analysis of the paleoenvironment at Tumbili will provide valuable new data bearing on the timing of the C4 vegetation expansion and the modernization of the African mammalian fauna. The fact that Tumbili is located on a high-elevation plateau far outside the EARS will add significantly to our understanding of the spatial and altitudinal variation of the habitats on the landscape during the Late Miocene.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.