I'm not comfortable with the notion that early man ventured forth simply out of curiosity; another problem I have is the obvious pigmentation differences among people of different geographical distributions while most modern mixed breeds tend to the darker parent almost exclusively.
The accepted notion of African origin is supported by the fossil record and the assumption that a benign climate acted as a stress-reducer for survival of offspring prior to established tribes or communes, but why would a satisfied animal leave such a benign climate?
All of this is too much for my small mind.
"I have is the obvious pigmentation differences among people of different geographical distributions while most modern mixed breeds tend to the darker parent almost exclusively."
I guess based on family experience I have to challenge this. I come from a mixed race African/European family and we have dark skinned and light skinned branches.(The light skinned tended to marry other light skinned persons.) I guess I'd say that it is very hard to predict how a child will turn out in my family looking at the parents.
That I've also heard that 500,000 African slaves were introduced to Europe and I don't see very many dark skinned Europeans so I don't think it is possible to make a generalization when races mix. What countries were you talking about?
Black African and black Americans look very different in my opinion and I don't think skin color means very much in the big DNA picture.
I have also read that Africans and Europeans share about 99% of the DNA so I don't think skin color counts for very much.