Developmental Basis of Craniofacial Shape Variation

The major focus of my current research is identifying the role of important cell-signaling pathways (Shh, Fgfs, Bmps, Wnts) in generating variation in developmental processes that impact craniofacial shape. Using a combination of landmark-based geometric morphometric techniques common to anthropology and experimental tools from developmental biology, I’m testing how variation in pathway activation in the embryonic face affects normal variation in the principal axes of facial shape (e.g., width, length, height and depth). Using this approach my research shows that the degree of pathway activation does affect midfacial growth variation (e.g., mitotic activity) and is predictably linked to a multivariate axis of shape variation in the embryonic face, driven primarily by facial width. This variation is also translated to phenotypes later in ontogeny. Information of this kind is critical to our understanding of the modular structure of the craniofacial complex, and thus the units of selection that underly observed evolutionary variation in primates.