Human of light skin

Discussion in 'Human Science' started by timojin, Nov 23, 2016.

  1. timojin Valued Senior Member

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    Was the African continent population always black ?
     
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  3. Fraggle Rocker Staff Member

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    They had to be, or they would have died from sunburn in the tropics. Clothing had not been invented yet--the first evidence of clothes is around 70KYA. So their skin had to have a lot of melanin, a very dark pigment that blocks solar radiation--and makes the people look very dark.

    As humans began to explore other regions, the ones who tried living farther from the equator had the opposite problem. The melanin in their skin was blocking out the weak sunshine and they were dying from vitamin D deficiency. Eventually, people with the mutation to reduce melanin were the ones who could colonize the colder regions.

    Regulation of melanin content is not a matter of dozens of genes having to come together--I seem to recall that only two genes participate. Thus, a population with low-melanin levels could have stabilized in a fairly short time--by the clock of evolution, anyway. For example, the relatively dark-skinned Indic people are very closely related to the relatively light-skinned Lithuanians and Latvians, and they're only separated by about 2,000 years of migration in opposite directions.

    Today, this isn't a major issue for humans. Light-skinned people from Sweden can live safely in Nigeria, with the help of sunglasses and dark, light-weight clothing. Whereas dark-skinned people from Nigeria can live safely in Sweden, with the help of Vitamin D supplements--and, of course, some very warm clothes.
     
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  5. timojin Valued Senior Member

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    What do you think about Berbers , their complexion is white they are from the northern part of African continent . The Berbers precedents invaded or colonised , the Canary Islands.
     
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  7. exchemist Valued Senior Member

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    I'm sure you can work that out for yourself. Starting, perhaps, with when you think this colonisation occurred, and then considering when clothing was first invented by mankind.
     
  8. Xelasnave.1947 Valued Senior Member

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    Why did our skin not go green so we could hide in the grass?
    Alex
     
  9. RuneSpider Registered Senior Member

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    Probably related to how no mammals have green pigment naturally.
     
  10. sculptor Valued Senior Member

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    It has been estimated that while the average non african human has between 1% and 5% neanderthal dna, most of that is clustered in dna for skin and immune system, with up to 65% of that dna being neanderthal.
    Which begs the question of Heidelbergensis dna and skin color. Heidelbergensis has been estimated to have existed for almost 1 million years and been in evidence from south africa through much(most?) of europe.
    During the superinterglacials of mis 19 and mis 31-33 would heidelbergensis have had any advantage in having either light or dark skin?
    If one or the other, would that advantage have been equal for the entire range of heidelberg's habitats?
    Or were there also light and dark skinned "races" of heidelbergensis?
     
  11. timojin Valued Senior Member

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    Very good inf. The Berber come from a culture is about 10000 old . The Berber are not dark as the Sub Sahara Africans. I am implying that before the tilt if the earth the population of Sahara had light skin
     
  12. sculptor Valued Senior Member

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  13. RuneSpider Registered Senior Member

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    The gene that gives Sub-Saharan Africans their dark skins predates our species.
    And it seems to have dominated until fairly recently.
     
  14. sculptor Valued Senior Member

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    Question:
    How do you know this?
     
  15. RuneSpider Registered Senior Member

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  16. Xelasnave.1947 Valued Senior Member

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    Europeans developed white skin to hide in the snow.
    Alex
     
  17. timojin Valued Senior Member

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  18. sculptor Valued Senior Member

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  19. Fraggle Rocker Staff Member

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    Well of course. Our pre-human ancestors lived in equatorial Africa, as did their increasingly more humanoid descendants. Once they began to be less furry (but still a long time before anyone invented clothing), they needed a high level of melanin in their skin to avoid dying of skin cancer.

    Roughly 60KYA, the first brave adventurers finally decided to explore the rest of the world and crossed the Red Sea in primitive boats. (This wasn't as difficult as it would be today, because it was an ice age, with much of the world's water trapped in glaciers and the polar caps, so sea level was much lower and therefore the seas weren't as wide.) As their descendants scattered to the winds, the ones who ended up farther from the tropics needed more Vitamin D from the cooler sunlight, and their anatomy responded by reducing the UVB-blocking melanin in their skin.

    Only a few genes are responsible for melanin processing, so it only took a couple of millennia for the Latvians and Lithuanians in the north to become much whiter than the Indo-Iranians, their close relatives in the south.

    However, once the other continents were populated, it wasn't so easy for Africans to emigrate, so right up to modern times, they still look a lot like their ancestors.
     
  20. exchemist Valued Senior Member

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    Very funny.

    More likely it was to synthesise vitamin D more effectively in the winter.
     
  21. exchemist Valued Senior Member

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    Tilt? What tilt?
     
  22. Xelasnave.1947 Valued Senior Member

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    They did not know about vitiman D.

    However I accept that you are correct.

    Alex
     
  23. joepistole Deacon Blues Valued Senior Member

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