Please refrain from making rather bold and frankly offensive assumptions about me and my beliefs. I don't have any, "racist preconceptions", as many others on this forum can attest to my love and affinity for cultures all across the world.
I say this because it seems to make sense to me that if Central Asia is the origin spot of mankind, then it makes sense how these civilizations cropped up in these distant river areas at relatively similar times. I wouldn't ever say mankind began as "white". It was so clearly not Caucasian in all of these places. They came way later. Incontrovertible until some hundred years or thousand years of fifty years later when new evidence comes up, as it so often does. I could very well be wrong, and I hold that I could be wrong right this moment too.. Perhaps I overlooked something, there is so much information out there, it's hard to learn it all. I just think it is a possibility that mankind came from Central Asia.