New Scientist
Image: llamnudds
Skin tone has varied greatly among humans for at least the last 900,000 years. So concludes an analysis of the genetic variants associated with skin pigmentation in people from several regions of Africa. The latest findings suggest that some particularly dark skin tones evolved relatively recently from paler genetic variants, underlining how deeply flawed the racist concept of people with whiter skin being “more advanced” really is.
Nicholas Crawford and Sarah Tishkoff at the University of Pennsylvania in Philadelphia recruited around 1500 ethnically and genetically diverse volunteers living in Ethiopia, Tanzania and Botswana for their study. Each person agreed to provide a DNA sample and have their skin pigmentation measured (pictured above).
The combined data allowed the team to find eight sites in the human genome that are particularly associated with the level of skin pigmentation. Together, these sites account for about 30 per cent of the variation they found in skin pigmentation among the volunteers.
For each of the eight sites of variation, there existed a genetic variant associated with paler skin, and a variant linked to darker skin. Seven of the paler skin variants emerged at least 270,000 years ago. Four of these arose more than 900,000 years ago. Read more on newscientist.com…
