I’m referring to the human race evolving in the African continent and then migrating to the rest of the world.

Evolving in Europe made people light skinned to account for the reduction in sunlight exposure, are there any other traits which other ethnicities developed to adapt to their new environment? Or are the diifferent traits in different ethnicities just stuff that developed by chance and got somehow reinforced because of the isolation between populations?

This question came to my mind first thinking about “Asian eyes”, do they serve any “purpose”?

  • @[email protected]English
    36•6 months ago

    Yeah, depending on what you consider “new”.

    • Nose shapes to account for dryer air on Africa and middle east.
    • Nose shapes to account for colder weather.
    • There are a group of people that have larger spleens to make them able to drive dive for longer periods (Bajau People).
    • “Asian” eye-shape, afaik, is an adaptation to protect the eyes from sand.

    The list is actually very long.

    • _haha_oh_wow_English
      25•6 months ago

      There’s also sickle cell anemia: IIRC it protects against something like the tse-tse fly or mosquito borne illnesses native to parts of the African continent

      • @[email protected]English
        19•6 months ago

        I believe that it offers a degree of protection against malaria. Or, enough protection that you live long enough to reproduce before dying a terrible, agonizing death.

        • _haha_oh_wow_English
          8•6 months ago

          Yeah, I think you’re right (on both counts unfortunately, but that’s evolution for you).

        • threelonmusketeersEnglish
          2•3 months ago

          Or, enough protection that you live long enough to reproduce before dying a terrible, agonizing death.

          I think it’s protective when you have one copy of the gene, and detrimental when you have two copies. Unfortunately, malaria was a strong enough pressure that the sickle cell gene was selected for, up to a certain percentage of the gene pool.

          • @[email protected]English
            1•3 months ago

            I thought that there was supposedly something about the altered shape of the cells themselves that offered a degree of protection from malaria? IDK, I don’t live in an area where malaria is endemic, so it’s mostly not a concern, just something we covered in biology and genetics in high school.

          • @[email protected]English
            2•3 months ago

            That trait didn’t appear in the region, so it could not be selected. It appeared in the east Asia, and were selected.

            Someone also commented that we don’t have conclusive evidence that some of those characteristics are adaptations to the environment, and could be just genetic drifts. So the shape of the eyes may be just a coincidence and not a real advantage.