University of California Scientists Offer New Take on the Evolution of Skin Color
Filed in Research & Studies on July 11, 2016
A study by researchers at the University of California, San Francisco, finds that darker skin is stronger than lighter skin and forms an important barrier against a host of environmental threats. Peter Elias, a professor of dermatology at the University of California, San Francisco, states that “work in our lab has shown that darkly pigmented skin has far better function, including a better barrier to water loss, stronger cohesion, and better antimicrobial defense.”
The authors speculate that the common assumption that Black skin developed on an evolutionary scale because it protected individuals from the harmful effects of ultraviolet radiation that can increase the risk of skin cancer. But the authors note that deadly skin cancer usually occur late in life, usually after the reproductive years so it would have limited impact on evolution. The other benefits of a darker skin may have more significance to human evolution.
The authors speculate that when humans moved North they needed more clothing for warmth. This clothing served the same purpose as darker skin as an environmental barrier. Darker skin which, according to the authors, is metabolically expensive to produce, was no longer as important to survival. “It’s all about diverting precious resources towards the most urgent requirements,” Dr. Elias said.
The study, “Basis for the Gain and Subsequent Dilution of Epidermal Pigmentation During Human Evolution: The Barrier and Metabolic Conservation Hypotheses Revisited,” was published on the website of the American Journal of Physical Anthropology. It may be accessed here.