i’m really dumbfounded that i never realized skin colour is literally just caused by being closer to or farther from the equator and the resulting sun exposure and skin darkening
actually, its an adaptation. natural selection. people with darker skin are selected for in areas near the equator, where the melanin that causes the darker color protects them from radiation and protects them from skin cancer and other health defects, and because they are healthier they can pass on that trait more. people near the poles have lighter skin because it allows them absorb more of the limited sunlight to convert to vitamin d.
THIS IS THE THING SOME PEOPLE HATE OTHER PEOPLE OVER.
Evolution of melanin levels based on geographical location.
Shout out if you grew up in No Data land!
iirc the theory goes, light skin was a mutation that was never selected against because it let in much more of the sun’s radiation which was needed to make vitamin D, which, in cloudier/darker/less sunny europe, people needed all they could get. And as well people began drinking milk of other animals which led to people who kept producing lactase long after childhood where they got calcium. Vitamin D is needed to digest and metabolize calcium, so when you didn’t get enough vitamin D from the sun due to weather, you wouldn’t metabolize the calcium, and even with the adaptations of digesting calcium-rich milk and having skin that let in tons of radiation, you’d get stuff like rickets and whatnot. Darker skin is predisposed to protect against harsh sun radiation since vitamin D is definitely not in short supply where your skin gets lots of exposure to the sun.
As diet improved, and you could get vitamin D AND calcium through your food, these adaptations stopped meaning as much as they used to, and you could go anywhere without, yknow, dying. Our bodies have changed so little while our civilization, food, and culture has so much.