Penn State anthropologist Nina Jablonski on the evolution of human skin pigmentation at the annual meeting of the American Association for the Advancement of Science in Boston on February 16th.

　　The variation in pigmentation is one of the most conspicuous and interesting features of human skin. In fact that within one species we have a wide variation skin pigmentation from very dark to very light, and that this pattern has a sensible geographical distribution that is related to the intensity of UV radiation is highly significant.

　　Ultraviolate radiation exerts such negative effects, predominantly negative effects on the body, strong malinen pigmentation evolved to protect us from most of those negative effects.

　　Loss of pigmentation was one of the most conspicuous things that occurred in these few small populations of homosapiens that left Africa arround 17,000 years ago. So that we actually see depigmented skin evolving in the ancestors of Western Europeans and Eastern Asians independently as a a result of independent genetic mutations, because this depigmented skin was very important to people living under low UV regimes. It allowed people to make Vitamin-D more easily out of available UV radiation in sunlight and it afforded tremendous evolutionary advantages.