I demolish your position:
te jen,
LOL.
Foot. Hole. You shot.
Nature created the 'strongholds' your talking about. Just look a map of the World. Africa and Europe have no common land bridge. Australia and its people - the Aborigines - are not just separated by geography but by time as well. Hundreds of thousands, possible millions of years of it. It is not possible to undo this with multi-culturalism.
For the most part - the only part which is relevant to this debate - Europe is white and Africa black. Just compare Britain and the Congo. No physical or intellectual commonality exists. Two separate races in two separate places. I don't know what your problem is with white Europeans or Black Africans being what they are.
Now, what color do you suppose those first humans were? Trick question, because the answer is irrelevant. We are the product of very, very slight differentiation of original physical and cultural trait expressions. We're not, as your statements imply, pristine and utterly separate tribes that should not mix.
Humans evolved from different species of primates.
This is why primates have different colored skin underneath their hair.
We were never the same in the first place.
Sorry if this scares you but it's the only sensible explanation rather than 'genetic mutation', 'out of Africa', 'evolutionary adaptation', etc, etc, blah, blah....endless intellectual somersaults because we cannot accept the reality that is right in front of our eyes.
We need to get back to basics and stop dealing in the liberal, free-market fairy tales that enable economic injustice and the rape of nature to continue.
Black and white exist. Nature created us - but not together.