Predicting someone’s face: look at their parents

Predicting someone’s face: look at their parents

A few years ago there was a paper out which illustrated that standard Galtonian method of regression of offspring upon parents still predicted height far better than the most modern genomic techniques. The issue is that height is a quantitative trait whose variation is controlled by variants at hundreds, and likely thousands, of loci. Generating a useful prediction for one individual from a “bottom-up” genetic model is daunting because of the overwhelming number of variants. This is in contrast to pigmentation traits, which been found to be well characterized by a few large effect quantitative trait loci. That is, one gene can account for a substantial minority of the variation within the population of the trait. In regards to eye pigmentation in Europeans the majority of the blue vs. non-blue eye color difference can be accounted for by one locus, HERC2-OCA2. Not so for height, intelligence, and now it seems likely, facial morphology.

A Genome-Wide Association Study Identifies Five Loci Influencing Facial Morphology in Europeans. The issue I’m alluding to is found buried in the paper:

Moreover, our data also highlight that the high heritability of facial shape phenotypes (as estimated here and elsewhere), similar to that of adult body height…involves …

Razib Khan