Evolution of human tooth enamel: unlocking hidden cell mechanisms
Understanding the ways in which we relate to our fossil ancestors is fundamental to elucidating how modern humans evolved. Yet, after a century of investigations, there is still no consensus about relationships among some members of the genus Homo. Studies of enamel thickness have been at the centre of these debates. Teeth preserve well in the fossil record and enamel thickness is a trait that can contribute to taxonomic classification. Yet, we know very little about the cell mechanisms that generate variation in enamel thickness. Several of our fossil ancestors have enamel that is of similar thickness, though it formed with very different underlying developmental processes. The goal in this interdisciplinary project is to combine 3D and 2D microtomography, histology, and theoretical biology to identify links between enamel growth and thickness to reveal novel traits in our fossil ancestors that will contribute new classification knowledge to our understanding of human evolution. I will examine modern day samples and fossil samples spanning the past 2 million years from the genus Homo. I will use the knowledge I gain to re-examine existing debates about which fossils are, or are not, ‘human-like’ to provide novel insights into their classification. Results will be of interest to anthropologists, human biologists, archaeologists, as well as the general public. My project will provide novel information about human growth and development that will also be of interest to clinicians.