[cyborg]

At the genetic level race takes on a different meaning than 'appearance' ID.

[ValerieUSA]

At the genetic level, I think early man contained a lot more info in his DNA than we do, allowing interbreeding within families to go on without much risk, but sprouting new tribes of people with similarities that they didn't share with their cousins - and then migrated in different directions. There's no spat like a family spat, nor split.
What we call races are refinements from the vast pool of traits contained within our earliest common father.
Esau's people went their separate way from Jacob's settlement.