Why is the white gene recessive?

[Blizzard_Owl]

I've heard the explanation that its to teach people not to race mix or something, but really why? White is the original human gene so why would it not evolve but devolve into becoming less dominant than the black gene. If whites have a much stronger affinity for spiritual power and the spiritual effects the physical then why is the white gene not a powerhouse whenever race mixing does occur?