DNA can already tell us the sex and ancestry of unknown individuals, but now an international team of researchers is beginning to connect genetics with facial features, degrees of femininity, and racial characteristics.
Writing about their work in PLOS Genetics, the researchers detail how by jointly modeling sex, genomic ancestry, and genotype, the independent effects of particular genes on facial features can be extracted. “By simultaneously modeling facial shape variation as a function of sex and genomic ancestry along with genetic markers in craniofacial candidate genes, the effects of sex and ancestry can be removed from the model thereby providing the ability to extract the effects of individual genes,” explained researcher Mark D. Shriver, from Penn State.
The researchers looked at both actual physical face shape and genetic markers of face shape. For physical face shape, the researchers used populations of mixed West African and European ancestry from the U.S., Brazil and Cape Verde. They placed a grid on 3-D images of the faces of the subjects and measured the spatial coordinates of the grid points. They then used statistical methods to determine the relationship between the variation in the faces and the effects of sex, genomic ancestry and genes that affect the shape of the head and face.