Howcomyoucom.com (linked at top of page) has a bunch of articles and essays related to this issue that the I's might want to check out.
There is a theory (which selassielive mentions further down this thread) that some Europeans have some neanderthal DNA... but even if so, neanderthals too were descended from people/hominids/whatever you want to call them who left Africa, all the earliest human ancestors have been found in Africa, in my opinion it's pretty much proved (as much as one can "prove" anything) that Africa is the origin of the human race.
As to the original question of the thread; until people get together and put up conscious cultural resistance (of which I see the Rastafari movemant as one example), the dominant culture will propagate like a virus and infect the majority of people. So it's the same reason why many Africans and other oppressed peoples of the world might prefer western clothing over their traditional attire, to listen to western/westernized music over their traditional forms of music. It is the same reason some people in Guyana, a country with some of the best cuisine on the planet, line up in front of KFC instead of going in their kitchen and making roti and curry and fu-fu and ting. Same reason a Guyanese acquaintance of my mum's told her, when she was about to move back to Guyana in the 70s with me and my baby brother, "But you can't go back there- you can't get baby formula there!" (Like my mum didn't have breasts).
