vrijdag 4 mei 2012

Case closed: blonde Melanesians understood | Gene Expression

Case closed: blonde Melanesians understood | Gene Expression:
As a small child perusing old physical anthropology books I would occasionally stumble upon images of people of Oceanian stock with light hair color. I would wonder: is this a biological or cultural feature? In other words, were people bleaching their hair? If it was biological, was it heritable, or was it simply malnutrition? Another aspect of the phenotype was also straightforward: it did not seem that light hair color resulted in any concomitant lightening of the skin. Granting that this was a heritable biological trait, the questions then were simple: was this trait an independent occurrence of de-pigmentation in Oceania, or was it due to introgression of European alleles?
First, one must note that this is not an isolated feature in Oceania. Rather, blondism crops up in the Solomon Islands, in New Guinea, as well as among some Australian desert groups. This in itself should make us skeptical of the model of European admixture. Additionally, blue eyes, which exhibits a higher frequency in Europeans than blonde hair, is not similarly common in these populations. But all this speculation is now a historical curiosity. The results are widely known from conference ...