Positive selection of hair, skin and eye pigmentation in Europeans over the last 5000 years

In the current issue of PNAS Wilde et al. find evidence for positive selection of skin, hair and eye pigmentation in Europeans during the last 5000 years. They looked at selection acting on three polymorphic sites that been previously identified in GWAS and fine-mapping SNP association as related to pigmentation in Europeans. They used ancient DNA and computer simulations to estimate the strength of selection on these genes. Their results and analyses indicate that positive selection on pigmentation variants associated with depigmented hair, skin and eyes has been operating within western Eurasia for the past 5000 years. The authors propose two hypotheses for the selection on hair and eye color, in particular. They hypothesize that changes in hair and eye pigment may be byproducts of a selection on skin pigment, or they propose that selection for depigmented eyes and hair may be driven by mate preference.