Corcovado wrote:
lawpoop wrote:
people are lighter skinned near the arctic and anartci. And the anthroplogists measure 'where the sun don't shine', like the armpit and groin, so they aren't just measuring amount of skin tan.
And there is a biological reason -- you need a certain amount of sunlight to synthesize vitamin D. Melatonin blocks sunlight. If you have too much melatonin, you don't get enough vitamin D. It you have too little, you can get sun poisoning.
For instance, in Finland, they have taken a lot of Somalians in as refugees. They have a lot of problems with vitamin D, especially in the winter, and they have to take supplements.
Actually the inuits on Greenland are have much darker skin than the scandinavian people, also be armpit meassure.
The problem somalis have in scandinavia is not only due to their dark skin, in Denmark it's mostly the women who lack vitamin D, and it's mostly because they cover themselves so only the face shows, both summer and winter.
You're right, when you compare groups of people to each other, some groups have darker skin than others.
However, when you look at the *overall*, *general* picture, people living closer to the equator are darker than those living closer to the polls, with pretty much an even gradient *on the *whole*.
Yes, you can find an albino guy on the equator, and you can find a really dark guy whose skin highlights are purple in a research center in Antartica. You can even find groups of people living in two neighboring villages that are darker or lighter than the other group.
However, *on average*, there is an even gradient of skin color from the equator to the poles.
As far as the Somali women having vitamin D problems from covering their skin, why don't they have the same problems in Somalia? They are covering their skin in Somalia, right? It's because their darker skin blocks more ultraviolet light than lighter skin, and there is less ultraviolet radiation in Scandinavia than there is in Somalia.
And in my experience, *everyone* covers their face in Finland in the winter. Bare skin is rather painful. And in the winter is when you have the least sunlight and at the lowest angle.