It's been said in the past that the Black race was engineered by the Gods first, as a sort of prototype. Then the Asians. And then the Gods created Whites as basically a "Master Race" meant to keep Earth in order when they left to return to the Orion galaxy.
Whites, unlike the other races, were created with actual blood of the Gods. Meaning we are Their descendants. It's also known that the Gods took certain Aryans as spouses and had children with them, making demigods. There are different White bloodlines that can be traced back to demigods.
Also, this is paraphrasing, but HP Cobra did say long ago that monkeys were a starting point in the Gods' research (as can be seen in Blacks more than the other races), but we are so evolved past that starting point that it's like comparing an unrefined stone to a magnificent castle.