Demystifying Skin Color and “Race”

Abstract

Historical confusion in thinking about skin color and race derives from the state of science at the time human classifications were proposed, and from our incomplete understanding of the genetics of human pigmentation and human ancestry. The pervasiveness of racism reflects the universal human desire for kinship, in settings of competition for resources, where it is common to devalue and harm other groups for the benefit of the group with which one identifies. To gain insight into the biological basis of skin color, scientists have studied the structure of pigmented tissues, hundreds of pigment variants in vertebrates, and a range of enzymes and molecules that affect melanin formation. We have learned that most population-specific traits can be explained by evolutionary chance, and that a small minority of traits, including skin color, have exerted a selective advantage during evolution. The selective advantages of dark and light skin color in the equatorial and more polar geographic regions, respectively, antedate sun screen and Vitamin D supplementation. Since modern technology has largely rendered these evolutionary advantages irrelevant, skin color has become a sociological issue that is amenable to reason. Education can play a central role in work toward a society free of racism, as long as that education is firmly grounded in critically evaluated science and is free of tribalism.