D3

Skin pigmentation changed long ago not only to protect skin from different levels of sun exposure--thats obvious--but also in order to regulate the amount of Vitamin D3 manufactured by the sun just under the skin. This is the theory of Professor Nina Jablonski, a paleoanthropologist with the California Acadamy of Sciences. So when the first swarthy inhabitants of modern Scandinavia confronted a lack of ultraviolet light, their kind quickly selected out for paler children whose skin would manufacture enough vitamin D3 to keep them healthy. Meanwhile, Eskimos arrived in the Arctic dark skinned. The local cuisine of seal and whale is rich in vitamin D3, so the skin was never summoned into action. Evolution has one big rule, if there´s no pressure on the system to change, then it doesn´t bother. So Eskimos remained dark.

When we look at the different races, according to Jablonski´s theory, what we´re actually seeing is not "superiority" or "good people", or "race". All that we are seeing, the only thing we are seeing when we look at skin color, is a meandering trail of vitamin D3 adaptation rates.