The human skeleton has continued to evolve over the past 40,000 years in Europe, long after the emergence of our species. During this period, major social, technological and demographic changes occurred as a mobile hunter-gatherer lifestyle gave way to sedentary farming villages, and then cities. This was accompanied by biological changes to our skeletons, which are retained into the present day. Our skeleton retains these biological changes into the present day, which include a decrease in skeletal robusticity, a shortened facial region, and smaller jaw and teeth, when compared to our distant ancestors. One of the most striking changes is the reduced size of our teeth and jaws. This dental reduction contributes to dental crowding for modern day Europeans, which requires extensive orthodontic treatment with a significant global socio-economic cost. These distinctive skeletal features of modern humans have led to many present day dental health and orthodontic problems, including dental crowding and malocclusion that continue to drain clinical dental practitioner's time, and public funds allocated to dental treatment for children.
Despite 50 years of academic debate amongst anthropologists and even though several hypothetical models have been developed to infer the causes of dental reduction, a consensus has still to be reached. Yet, we know nothing about the cell mechanisms that actually facilitated the reduced size of our teeth and jaws in Europe.
The goal in this project is to develop an original, interdisciplinary and holistic approach that combines dental and bone analysis at three structural levels, to identify and describe the micro-evolutionary cell mechanisms that led to the reduction of modern human teeth and jaws in Europe. Combining cutting-edge histological and microtomographic techniques, I will examine molars and jaws from prehistorical, medieval and modern samples, spanning our most recent evolution from ~38,000 years ago to the present day. The overall objectives are 1) to identify the cell mechanisms governing tooth size and jaw size, 2) to assess growth, proportions and size of teeth and jaws in late Pleistocene and Holocene human populations and 3) to re-evaluate the existing hypothesised causes of dental reduction. This project will provide a unique biological insight that will help to resolve a long-standing debate, and reshape our understanding of dental reduction during recent human evolution.
