Supervised by Dr. David Pilbeam, doctoral candidate Bridget Alex will produce improved radiocarbon-based chronologies of modern human and Neanderthal distributions in three regions of potential contact between the populations. The revised chronologies will help to constrain where and when they overlapped. In such a context the archaeological records of both groups can be compared in order to identify meaningful differences and possibly, adaptations unique to modern humans. This comparison is one approach to a fundamental question of anthropology: what is unique about modern humans and why did other human populations go extinct?
Mapping the distribution of Neanderthals and modern humans in time and space is problematic. The underlying issue is how to demonstrate that dateable material (mainly organic carbon) relates to the presence of a particular human population. A number of theoretical and methodological innovations have been developed to support the links between radiocarbon dates and population occurrences. First, due to the paucity of taxonomically unambiguous, directly dated human fossils, most population occurrences are inferred from archaeological proxies. To classify archaeological populations, scholars have shifted from artifact-based typologies to broad behavioral packages, or culturally specific suites of idiosyncratic choices in the production of material culture. Next, the production of reliable radiocarbon dates requires rigorous evaluation of the context, taphonomic history, and preservation of potential samples. Essential to this process is an integration of fieldwork and laboratory analyses, so that the same investigator can document the full post-excavation history of samples, and better explain anomalies. Lastly, radiocarbon samples should be prepared by state of the art pretreatment procedures designed to remove contaminants.
Alex will synthesize these innovations to produce reliable radiocarbon dates for active excavations in three regions of potential overlap: Manot Cave in the Levant, Pe'turina Cave in the Balkans, and Ciemna Cave in Northeast Europe. The new dates will be combined with critically reviewed published dates to produce secure regional chronologies, which can be used to evaluate the likelihood of Neanderthal-modern human interactions in each region. The project will provide a research framework and critical data pertinent to one of the most debated topics in anthropology: the relations between modern human dispersals, Neanderthal extinctions, and cultural changes between 50-30 ka.
The project aims to impart broad, desired societal impacts. It requires and will facilitate international collaboration between scholars in different fields, including archaeology, biological anthropology, earth sciences, and chemistry. Alex will be mentored by scientists from diverse perspectives, and will disseminate this training to students at home and abroad. The methods and results will be shared with the public through a variety of outreach organizations, with which Alex is actively involved. The organizations include the Harvard Museum of Natural History and Peabody Museum, as well as Science Club for Girls, a program that provides science experiences to girls and minorities. Lastly, the topic of Neanderthal-modern human interactions enjoys widespread public interest. Alex regularly offers public lectures on the topic, which are excellent opportunities to educate the public on the scientific method, evolution, and climate change.
