1Anthropology, Penn State University, 2Biology, Indiana University-Purdue University Indianapolis, 3Electrical Engineering, Katholic University Leuven, 4Medical Imaging Research Center, UZ Leuven, 5Biology, Penn State University, 6Oral Biology, University of Pittsburgh, 7Developmental Biology, Stanford University School of Medicine, 8Ecology and Evolution, Princeton University
March 28, 2019 4:00, CC Room 26 C
Recent discoveries of genes shaping facial variation are helping us address questions about patterns of facial variation in humans. For example, how much of the genetic architecture underlying facial shape is shared across populations? We propose a framework for determining the extent to which global facial variation is driven by variants discovered in European cohorts: We examined 218 SNP peaks resulting from a meta-analysis GWAS of two large cohorts of European ancestry (N = 7,632) for allele frequency correlations among 26 population groups from the 1000 Genomes Project (1KGP). Using diverse facial and genetic databases, we constructed population-specific ancestry consensus faces for the 1KGP population groups. We quantified the effect size of SNPs discovered in a European GWAS on 1KGP consensus faces and compared these average facial effects to the allele frequencies. We identified 53 loci (24.3%) passing the False Discovery Rate threshold of 0.0019 and 29 loci (13.3%) passing the Bonferroni threshold of 0.00023, including ALX1, FGF8, SIX1, and TRPS1. These results suggest that contemporary global patterns of craniofacial diversity are shaped by clinal variation in allele frequency for loci that are shared across populations. Several of these loci also show signatures of selection and are enriched for archaic alleles. This suggests that selection and archaic introgression played an important role in shaping human craniofacial diversity. While our study demonstrates the utility of SNPs discovered in European cohorts, GWAS in diverse, underrepresented populations will further advance our understanding of the evolutionary history of facial form.
PSU Center for Human Evolution and Diversity (CHED)