Skin Coloration

Human skin is functionally hairless and exhibits a wide range of natural colors from the most deeply saturated dark brown to pinkish off-white. Differences between people in skin color are readily perceived and have been used as the basis for classifying people into groups referred to as races or race-color identities (Harris et al.,1993). The array of colors observed in the skin of modern humans is greater than that of any other single mammalian species, and is the product of natural selection (Jablonski and Chaplin, 2000), despite some arguments to the contrary (Blum, 1961; Frost, 1988; Robins, 1991; Aoki, 2002). Skin pigmentation in humans evolved primarily to regulate the amount of ultraviolet radiation (UVR) penetrating the skin and, thus, modify its bioactive effects.