eli5: If more melanin is advantageous in warm climates, why is less of it advantageous in colder climates? Wouldn’t darker skin still be most advantageous in cold climates where it might occasionally be hot?

Question

eli5: If more melanin is advantageous in warm climates, why is less of it advantageous in colder climates? Wouldn’t darker skin still be most advantageous in cold climates where it might occasionally be hot?

In: 1641

Answer 1

No! Because lighter skin has its own advantage for places that get less sunlight than around the equator-you can absorb vitamin D easier with lighter skin.

(here’s your note that, if you’re darker skinned in a colder climate, and you’re tired all the time, get checked for vitamin D deficiency! It’s very normal to be deficient when it’s harder to absorb and there’s less sun in general)