Hallgrimsson, BenediktDa Silva, Cassidy2021-12-232021-12-232021-12-21Da Silva, C. (2021). The Genetics Underlying Male-Female Facial Sexual Dimorphism (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.http://hdl.handle.net/1880/114234The genetic mechanisms underlying facial sexual dimorphism are currently unknown. My thesis addresses this gap by shedding light on the genetic and biological mechanisms underlying sexual dimorphism in human facial shape, as well as normal facial variation more broadly. I evaluated the shape differences between males and females, scored their shapes for sexual dimorphism, and looked for genetic loci and genes that had significant associations with sexually dimorphic facial shape. While none of the SNPs reached genome-wide significance, testing revealed seven independent signals with suggestive associations (p < 1 × 10-5) to facial sexual dimorphism, spanning coding regions in four different genes. Three of these genes, RBFOX1, CACNA2D3 and ATP6V1E1, have previously been implicated in processes of craniofacial development. I also examined the shapes and genetic aetiologies associated with sex chromosome aneuploidies, Turner syndrome (X0) and Klinefelter syndrome (XXY), which yielded no clear indication of the role of the X chromosome in sexual dimorphism of the face. These findings support the most recent evidence that the same genes influence facial sexual dimorphism in both males and females. Furthermore, by identifying genes previously linked to normal facial variation, I provide preliminary evidence for developmental mechanisms underlying shared variation in facial sexual dimorphism between the sexes. Only by properly understanding the mechanisms underlying facial sexual dimorphism will we be able to form a complete picture of its role in human evolution.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Geometric morphometricsGWASFacial sexual dimorphismAnthropologyBiologyGeneticsmaster thesis10.11575/PRISM/39475