Why do Spaniards have white skin?
Skin color: How Europeans got their white skin color
So far, researchers have always explained the loss of the dark color to a vitamin D deficiency, which was caused by the one-sided grain diet of early farmers in Europe: Sun UVB light can only penetrate so deeply into light skin that it can stimulates the body's own production of the vitamin. Vitamin D deficiency causes, among other things, a rachitic deformation of the bones - affected women have a deformed pelvis and cannot have children. For example, fair-skinned people helped early Europeans get the essential vitamin dose - and ultimately they were the prerequisite for survival on the cool continent. So much for the traditional doctrine.
Vitamin D Deficiency Myth
The South African researcher Ashley Robins has now dispelled this theory with a study in the “American Journal of Physical Anthropoloy”. “The black pigment melanin doesn't shield all UVB rays,” he says. Dark-skinned people only need six to ten times as much sunlight to achieve the same vitamin D level in their blood as fair-skinned people. "For an African in Europe that means in practice that he would have to get two to three hours of sunlight, three times a week," says Robins of the "New Scientist", "the early humans on the European continent had at least that much every day." Robins considers it unlikely that they suffered from a life-threatening vitamin D deficiency.
Robins compared the levels of vitamin D in the blood of whites and blacks. "Although dark-skinned people need a lot more sun to produce the same amount of vitamin D, they compensate for this disadvantage by making their bodies a lot more metabolic products from the same amount of vitamin," says Robins. Apparently, the enzymes of the dark-skinned people work harder in the liver and kidneys and so the bottom line is that they have the same amount of vital metabolic products as the light types.
White skin seems more in need of protection
So where does the pale skin come from? "There are probably many reasons," says the Norwegian Asta Juzeniene, "one of them is sexual selection." With the arrival in cool Europe, the light, sensitive skin suddenly no longer posed a health risk for people, she wrote in May in the " Journal of Photochemistry and Photobiology B ”,“ and so the sexual taste of men in particular changed - the lighter a woman, the more attractive. ”A preference that has apparently persisted to this day, as psychologists know from surveys. "Men instinctively see in fair skin the sign of untouchedness, flawlessness, innocence - maybe even a need for protection," according to a study by the University of Toronto from March 2008.
In addition to the eroticism, the Norwegian Juzeniene also sees another selection advantage of the fair complexion: the sensitivity to frost. Studies among soldiers in the Korean War have shown that blacks get frostbite more easily than their white counterparts.
All brown in the future
The gene for skin color was discovered almost four years ago - as one of those characteristics in the genome that has changed the most and fastest over the millennia - and is still changing. In which direction? “Brown,” says evolutionary researcher Steve Jones: “More and more children are being born in Africa. Perhaps at some point the genes for black skin color will become more common than those for white skin color. If globalization continues, it means that one day we will wear brown skin. "
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