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”?