Narok Paleontological Survey Project

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Molecular studies have concluded for decades that the evolutionary split between the human and great ape lineages occurred during the Late Miocene, c. 5-8 ma. Only recently has the paleontological evidence started to provide significant anatomical data about this divergence. Fossils from Chad, Ethiopia, and Kenya shed the first light on what our earliest ancestors were like, where they lived, and what the evolutionary forces may have been that ultimately resulted in the species we know today. The sedimentary deposits in which we find these Late Miocene remains are rare and difficult to locate. Despite the difficulty and challenges, their yields are of critical importance to reconstructing the evolution of the human lineage. This High Risk Research in Anthropology project is a systematic paleontological survey of the area around Narok, in southern Kenya. The Late Miocene site of Lemudong'o was discovered in this region in 1995 and has since yielded fossil remains suggesting the type of habitat in which hominids are found in other areas of Africa (closed/woodland environment). Geochronology places the site securely at 6 ma. Lemudong'o Locality 1 is a very small site and has not yet yielded hominids. An imagery-based survey of the region is proposed to locate additional outcrops of these same sediments, increasing the number of fossils recovered and increasing the likelihood that if hominids lived in this area 6 ma, and if they were preserved in these sediments, some of their remains can now be found. Though this survey project is high-risk, the intellectual merit of the proposed activity and the potential for success is high given the recent documentation of Late Miocene-aged deposits in the area. The team members have done considerable research at Lemudong'o Locality 1 and the immediately surrounding area. Therefore, we already have an understanding of the geology, terrain, local people, and perhaps most importantly, ground truth to apply to an imagery-directed survey approach. Satellite and other imagery-based survey approaches have proven to be highly successful and the PI has considerable experience working with this approach with colleagues in Ethiopia. The broader impacts resulting from the proposed activity span throughout the biological sciences and geology to the general public at large. Success in finding hominid-bearing Late Miocene sediments will immediately contribute significantly to the known range in geography and biological variation of early hominids. Just one tooth would shed light on the apparent morphological differences between the Late Miocene hominids of Ethiopia and Chad compared to those from more northern sites in Kenya. Many fossils aside from hominids will be recovered, contributing to the field of vertebrate paleontology. The geological work that will take place in conjunction with this survey project contributes to the larger understanding of rift valley systems and the patterns and process of continental plate tectonics. And finally, human biology is rooted in evolution. The more we understand about the animals through which we evolved, the better we understand our modern biology and biological variation, with an impact that reaches from biomedical advances to sociopolitics.