[Coyoteman]

I think Homo sapiens is a killer by nature and in snow covered northern Europe, a white skin stands out less than a darker skin. Some early cro-magnon with a club would have a harder time finding a white slinned target to brain than a darker skinned target.

And vice-versa in a tropical jungle.

Skin color is almost entirely an adaptation to sunlight levels below about 45 degrees north latitude. There is a need to balance UV protection of the skin vs. production of vitamin D.

The exception to this is the extreme north latitudes, where no amount of skin lightening would produce the needed vitamin D, and the extreme cold would kill anyone trying (it would also kill a naked white-skinned hunter). In those areas the skin color is more world-average brown, and vitamin D is obtained from things like fish oil.

[frgoff]

One of the finest examples of circular logic I have seen in quite a while.

Translation: Sunlight selects for skin darkening. Except where it doesn't.

I heard this textbook explanation in my Human Anthropology class, too, and my first question to the teacher was: "What, only Eskimos eat fish?

Flaw #1. Clothing protects from sunlight.

Flaw #2: Anyone can eat fish and animal organ meats at any latitude, but more commonly at northern lattitudes where such food is easier to obtain than growing or foraging for plants. Therefore, there is no advantage to a lighter skin because diet compensates.

The reality is, we really don't know what selected for White skin in higher latitudes. The scientists discovering the gene frankly admit as much in their article.