Beyond anything else, sub-Saharan Africans show by far the most genetic diversity of any human "race".
I am aware. However, that genetic diversity does not manifest itself in physical diversity*, which is what this thread is about.
*Unless one lumps Khoisan and Pygmy people in with black Africans. Which I suppose that one could, since race is entirely made-up anyway.
Surely if you really wanted to boost diversity, genetic diversity is ultimately far more important than physical diversity? Seeing as a lack of genetic diversity could lead to a lack of adaptability, while a lack of physical variation doesn't really matter at all.
Light eye and hair colours simply aren't very advantageous in the tropics. They come with decreased melanin production and nobody wants a lack of melanin in Africa.
