Personally I subscribe to the "Out of Africa" theory of evolution. We're all of the same origin in my book.
However humans love their boundries, their land, their religion, their cultural ethnicity and are willing to fight, kill and die for it. We will not come together as a species until those boundries are trancended.
Maybe it's becase I'm a European mutt... my ancestors are so diverse I'm 1/16ht of a lot of things. I have no history, no ancestry. So come on people, keep the inter-racial/culture/religion/ethnic unions going until we are all the same hue. Then we can find something else to fight, kill and die for.