A new study led by researchers at the University of Pennsylvania has identified genetic variants associated with skin color. Researchers used a light meter to record skin color variation on 2,000 people across Africa. They then took samples DNA samples from survey participants and were able to determine genetic variants that impact skin color.
Sarah Tishkoff, the David and Lyn Silfen University Professor in Genetics and Biology at the University of Pennsylvania, and a co-author of the study, notes that “when people think of skin color in Africa most would think of darker skin, but we show that within Africa there is a huge amount of variation, ranging from skin as light as some Asians to the darkest skin on a global level and everything in between. We identify genetic variants affecting these traits and show that mutations influencing light and dark skin have been around for a long time, since before the origin of modern humans.”
Both light and dark skin pigmentations confer benefits: Darker skin, for example, is believed to help prevent some of the negative impacts of ultraviolet light exposure, while lighter skin is better able to promote synthesis of vitamin D in regions with low ultraviolet light exposure.
Professor Tishkoff states that “analysis of the genetic basis of variation in skin color sheds light on how adaptive traits evolve, including those that play a role in disease risk.” The findings help explain the vast range of skin color on the African continent, shed light on human evolution, and offer clues on the migration of early humans.
The study, “Loci Associated With Skin Pigmentation Identified in African Populations,” was published in the journal Science. It may be accessed here.