Genetics takes thousand of years to change in animals a
Sorry, genetics changes in animal and humans take thousands if not millions of years to change.
If you could trace back all the slaves that were taken from their homeland you could actually see where and who they share direct genetics from.
And your question about what people in Africa don't produce talent, umm probably because sports is not important when you have to actually have to get by every day and provide safety and food.
They don't get the luxgery of the soft first world nation to play sports for hours a day. I can't believe you would even ask the dumb question.