The genetics of Scottish hair color variation

In the aughts the elucidation of human pigmentation genetics was of one the major successes of ‘omic’ techniques. The fact that humans exhibit some continuous variation in complexion was strongly suggestive that more than one gene was at work to generate the range of the phenotype. On the other hand pedigree based studies going back to the 1960s suggested that only a modest number of large effect genetic variants were producing the variance. Today we can say with reasonable certainty that about half a dozen genes account for almost all the between population variation in pigmentation. For example, on the order of 1/3 of the difference between Africans and Europeans in regards to skin pigmentation can be accounted for a genetic difference on the gene SLC24A5. Unlike height the genetic architecture of human pigmentation variance was ideally suited to being explored by the power of contemporary GWA; moderate frequency and moderate effect variants are numerous.