I kind of understand what
@Mowgli means, for Africans you are what your father is. That's why they don't really give a shyt what tribe/race a man marries because his children will still carry on his name, but for the women it's a no no because she takes on her husband's lineage and her children carry his name and not hers. That's what happened with my Ethiopian mother. She was her father's tribe, but since she married out, I carried on my father's lineage (black American) rather than hers and that created a rift.
However I just don't think that's logical, if a man is black and his kids don't even look like him, those kids are not exclusively his lineage and will most likely marry out which essentially wipes away his lineage.