Question: i've been wondering about melanin. according to my science teacher, it happened because of "survival of the fittest" and i understand that but i still don't know if it was white people that evolved to have it in their skin or is it the other way around?

Erin Pallott answered on 7 Apr 2025:

Genetics is not my area of expertise, but here is where I read about it: https://anth.la.psu.edu/research/research-labs/jablonski-lab/evolution-of-human-skin-and-skin-pigmentation/

Melanin acts as a natural sunscreen, protecting against harmful UV rays. Essentially, it helps minimise UV damage to DNA while allowing enough UV light for vitamin production. So for the survival of the fittest, the first humans on the African continent would have needed enough melanin to balance between those two.
As humans migrated North, they evolved less melanin to allow enough vitamin D production in areas with less intense sun. So essentially, white people evolved to have less melanin than their ancestors who had more.

I hope this helps, and maybe a geneticist can provide more information!