Posted on 09/02/2009 12:47:20 PM PDT by SeekAndFind
Humans come in a rainbow of hues, from dark chocolate browns to nearly translucent whites.
This full kaleidoscope of skin colors was a relatively recent evolutionary development, according to biologists, occuring alongside the migration of modern humans out of Africa between 100,000 and 50,000 years ago.
The consensus among scientists has always been that lower levels of vitamin D at higher latitudes where the sun is less intense caused the lightening effect when modern humans, who began darker-skinned, first migrated north.
But other factors might be at work, a new study suggests. From the varying effects of frostbite to the sexual preferences of early men, a host of theories have been reviewed.
Vitamin D plays an important role in bone growth and the body's natural protection against certain diseases, and the inability to absorb enough in areas of less-powerful sunlight would have decreased life expectancies in our African ancestors. The further north they trekked, the more vitamin D they needed and the lighter they got over the generations, due to natural selection.
This explanation accounts for the world's gradients of skin color traveling south to north, the prevalence of vitamin D deficiency among African immigrants to higher latitudes, as well as the relatively darker skin of Canada's Inuit peoples, who have good levels of vitamin D despite living in the Arctic, due to their diet rich in oily fish.
(Excerpt) Read more at livescience.com ...
The naturally darker ones bred more while the pale ones said "Ow! Ow!" because of their sunburns when they tried to.
I thought that was the name of Ben & Jerry’s new ice cream ... oh, wait ... It wasn’t Home Erectus, it was Hubby Hubby. nevermind
It’s an evolution things—higher levels of melontonin protect the person from the effects of the sun. Hence, one becomes “bronzed” or “tanned” when they spend a long time in the sun.
Very interesting, I have been wondering about that Fifty Percent of me all of my life./Just Asking - seoul62.......
I think because they hunted by day. Or lived in the snowy areas where they could blend in. Like good Cammo. Blacks were probably nocturnal hunters.
Photoshop. We are all actually green.
That’s too funny. I was thinking of Jackson when I read the title. LOL
So, regarding hispanics, it is not entirely stupid to consider hispanics a different race from whites because it seems pretty certain that you can choose the radius in a way that will clearly seperate them. Whether it is important, or desirable to do so, that is a different question.
According to some of the more benighted and ignorant creationists, the human genome can only be ‘degraded’ after the Fall of mankind. White skin is caused by mutations that render nonfunctional some of the genes that would make the skin black.
Thus according to that way of “thinking” blacks are not only the first humans, but also more in the ‘perfect’ original state of mankind - and whites have degraded from that more perfect state of humanity.
I sure they’re presenting this as a theory....All their buddies will now jump on the bandwagon.....and it’s GRANT MONEY.....forever...Just like Darwin’s Theory!!!
“Why Did People Become White?”
So they could invent virtually every technological and medical wonder and be totally awesome?
What happened with Asian people if that’s the case?
Why Did People Become White?
So they could work on a great tan.
Added some soy sauce. ;)
Indian anthropology?
Deep common ancestry of Indian and western-Eurasian mitochondrial DNA lineages.
http://www.ncbi.nlm.nih.gov/pubmed/10574762
Kivisild T, Bamshad MJ, Kaldma K, Metspalu M, Metspalu E, Reidla M, Laos S, Parik J, Watkins WS, Dixon ME, Papiha SS, Mastana SS, Mir MR, Ferak V, Villems R.
Department of Evolutionary Biology, Tartu University, Tartu, 51010, Estonia.
About a fifth of the human gene pool belongs largely either to Indo-European or Dravidic speaking people inhabiting the Indian peninsula. The ‘Caucasoid share’ in their gene pool is thought to be related predominantly to the Indo-European speakers. A commonly held hypothesis, albeit not the only one, suggests a massive Indo-Aryan invasion to India some 4,000 years ago [1]. Recent limited analysis of maternally inherited mitochondrial DNA (mtDNA) of Indian populations has been interpreted as supporting this concept [2] [3]. Here, this interpretation is questioned. We found an extensive deep late Pleistocene genetic link between contemporary Europeans and Indians, provided by the mtDNA haplogroup U, which encompasses roughly a fifth of mtDNA lineages of both populations. Our estimate for this split is close to the suggested time for the peopling of Asia and the first expansion of anatomically modern humans in Eurasia [4] [5] [6] [7] [8] and likely pre-dates their spread to Europe. Only a small fraction of the ‘Caucasoid-specific’ mtDNA lineages found in Indian populations can be ascribed to a relatively recent admixture.
PMID: 10574762 [PubMed - indexed for MEDLINE]
It strikes me that very dark pigmentation is as specialized as, or even moreso than, very light pigmentation.
The whole “Out Of Africa” thing was designed to subvert the dominant paradigm of the era in which it was first introduced, imho. It was, and is, political. The “scientific” assumptions upon which the theory was based, are sketchy, as we’re seeing now.
The ugly thing about this theory, is that it’s racist, itself. The base assumption is that the smart ones got out. What does that say, about those who remained? Just about the same thing Darwin said, come to think of it.
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