Converse to expectations above it turns out that on the two largest effect genes explaining difference between Africans and Europeans the light alleles are more dominant than the dark alleles! In other words, if the two alleles had an equal effect you’d expect a value between the two in their homozygote state. As it is, the values tend toward higher reflectance (light) than dark.
This is an extract from discovery.com written by a biologist
