The Geological Context of Hominin Fossils

This project focuses on one of the most pressing questions in the study of human evolution, the replacement of Neanderthals by modern humans. Neanderthals, who evolved in Europe and were established there for over 200,000 years, vanished from the fossil record shortly after modern humans entered the area approximately 50,000 years ago. Current explanations for Neanderthals' disappearance center on their inability to compete with modern humans, who had symbolic culture and more advanced technologies. Yet, genetic evidence shows that the two populations made contact and interbred. What was the nature of this contact? Archaeological evidence to answer this question is present at one archaeological site. Fossilized bones of Neanderthals and modern humans have been found in the same stratigraphic layer, meaning that the two populations were contemporaneous. However, some evidence suggests that the modern human fossils may be younger and accidentally became incorporated into an older layer. The focus of this project is to apply numerous scientific techniques to test whether the fossils were deposited at the same time or not. If contemporaneity is confirmed, this site will be the first to provide direct archaeological evidence of the period of interaction when modern humans and Neanderthals met. In addition to answering the scientific questions, the project will train students in cutting-edge methods of archaeological excavation and analysis and provide field as well as lab-based research opportunities for undergraduate and graduate students. Career-building opportunities abound. Undergraduate students needing fieldwork to get jobs or get into graduate school gain valuable skills through their participation in the project. Graduate students' theses benefit from their access to first-class research materials, and networking opportunities with scientists from the U.S. and other countries will expand their job prospects. This project helps to clarify a crucial period within human evolution. The site is likely one of the earliest sites where such contact occurred. In order to test the contemporaneity of the Neanderthal and modern human fossils, specialists examine the preservation of the bones, radiocarbon date them, and attempt to extract DNA from them. The geological stratigraphy of the site is studied using microscopic and chemical analytical techniques. All of these analyses are necessary to confirm the rare discovery that modern humans and Neanderthals were present at the same time, in the same rockshelter. 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.