Why are Arabs whiter than Indians?


My understanding is that, the more the melanin = the better the protection from sun.

If that’s the case, why do most Arab people have less melanins than Indian people, when there is more sunlight in the Middle East than there is in India? Shouldn’t it be opposite? And by the virtue of that, shouldn’t Indian people have a lighter skin tones than the Arabs?

(P.S. My question stems from my personal observation having lived both in India and the Middle East and I know that darker toned Arabs & lighter toned Indians do exist in plenty)

In: Biology

Evolution does not produce the perfect result. It is most commonly just evolving traits which is good enough or even not that. So you should not expect people to have evolved to perfectly suit their environments.

However I can try to offer a theory of why Arabs are lighter skinned then Indians. The main difference between these areas are the humidity. The Arabian penincula is quite arid while the Indian subcontinent is much less so. There is also much less trees and vegitation in arid conditions which also means more wind. And with a steady dry wind your sweat becomes far more efficient at keeping you cool so you can wear more clothes to protect you from the heat of the sun. While in India you want to expose as much skin as possible to cool yourself down, which of course means that you need more protection from the sun.

It may also have to do with the migration of ancient peoples and the fact that we have not had enough time to fully evolve to our current environment (plus the fact that over the past few thousand years we have had advancements in housing, etc that has protected us from the environmental effects such as sun)

>there is more sunlight in the Middle East than there is in India

Is there really?

The tradeoff for skin color is that dark skin protects against sunburn while light skin protects against vitamin D deficiency. For both of these what matters most is the *directness* of the sunlight, not temperature or humidity. And if I look at a map, it looks to me like the Middle East–especially the densely-populated part–is somewhat to the north of South Asia on average.

I imagine it might be something to do with the population sizes of when the people settled there. A lot of features we have evolved in smaller populations a long time ago. More recently we have so many more people it would take longer to evolve new traits as they would just get diluted into the larger population.