Do you think part of the reason people from cold snowy climates are very pale skinned is camouflage?
Asked by
JLeslie (
65790)
April 7th, 2012
I have heard the theory that human beings became whiter as they migrated north thousands of years ago to soak up more vitamin D. But, this morning I was looking at the deer in my backyard. One sign of spring here is the coats of the deer turn from grey to brown. Grey in the winter blends in better with the grey of the woods during the winter months, and brown better with the summer colors of the forrest. I never thought of it before….did human beings evolve their skin color to blend in with our surroundings? To keep us safer during a more primitive time?
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15 Answers
I don’t think so. In a white world, almost all of that skin is going to be covered up anyway.
No, it was lack of sunlight.
Native Inuit peoples aren’t pale.
Holland is mostly green, as are many European countries, where traditionally many / mostly white people lived.
Nah, it’s bloody freezing here in england town, especially in the winter & most of the population have noses that would put Rudolph’s conker to shame.
This is true of some animals of the north. Rabbits, wolves. Their fur changes color through the year to match the landscape, for camouflage and all. Things like polar bears don’t need to, but a rabbit needs to blend in to hide, a wolf needs to blend in to hunt…but that doesn’t happen with humans.
Inuits have dark skin…they’re the only people I can think of that have lived thousands of year in a place that barely has a Summer.
No, people in very northern latitudes just don’t need as much melanin to protect from year round UV exposure.
From wikipedia:
From ~1.2 million years ago to less than 100,000 years ago, the ancestors of all people alive were from Africans which had dark skin.
As populations began to migrate, the evolutionary constraint keeping skin dark decreased proportionally to the distance North a population migrated, resulting in a range of skin tones within northern populations.
At some point, northern populations experienced positive selection for lighter skin due to the increased production of vitamin D from sunlight and the genes for darker skin disappeared from these populations.
I mentioned the vitamin D in my original question.
Not that I am trying to push my theory/thought, but people in the coldest climates would be covered head to toe as @thorninmud said, so maybe they would not change skin color as fast? Mentioned was the Inuits, who I know very little about. They did not get whiter for D absorption, so possibly not whiter for camoflage either. They seem to be an exception to both ideas. Red skin, is an old derogatory term for Native Americans. Reddish skin from the areas of reddish soil and clay? White people can and do tan in the summer. It just seems like skin color seems to sort of match up with the climate in areas of the world. I also believe D plays a part, goodness knows I am D deficient, but interestingly because I burn very quickly, I super protect my skin. My husband who is a few shades darker than me always has great D levels, because he goes out in the sun and tans.
@whitenoise Not the green, the brown of the trunks and branches of the trees. In the winter Northern Europe has grey trees and snow.to be green would would probably have to have chlorophyl, which would have been a big leap in evolution I guess, and not work in winter mo ths.
@JLeslie You make me homesick of Holland. Holland is green… always.
Except when it is white, then it isn’t.
But that doesn’t happen so often and that wouldn’t be the right time to run around naked showing of your skin color. (Again, there are the Finnish people.)
@whitenoise I can imagine. I have only been to the more arid areas of the US a couple times, and I know I am not a desert person. Not the air, not the flora, and not the fauna.
Inuits get their vitamin D from dietary sources (there’s loads of it in the oils of arctic fish and the livers of marine mammals), so they didn’t experience the selective pressure for paler skin.
@thorninmud That is also true for the Nordic countries if memory serves. Herring stands out in my mind as being a very good source of D, and I am pretty sure Sweden consumes a lot of it, maybe the other surrounding countries as well.
@JLeslie The area we now call Scandinavia was buried under the ice sheet of the last ice age until relatively recently, so the coastal areas weren’t accessible to human settlement. Early Europeans had to just hang around the southeastern edge of that ice sheet for a very long time. The humans who eventually settled there would have already had to adapt to inland life in a light-poor environment. That favored pale skin.
The Inuits (like virtually all native Americans) have genetic markers that tie them to a single South Asian ancestor. The migration across Asia and the Bering Strait to North America happened relatively quickly and deposited them along the coastal areas of present day Alaska, where they had access to D-rich foods. This happened long before coastal Scandinavia was settled.
The end result seems to have been that the ancestors of the Inuit spent less time in environments where their dark skin posed a problem.
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