Yes, but still the overall genetic differences are very small. All different races can have offspring with each other.
True, but those genetic differences make sub-Saharan (euphemism for black) Africans a separate subspecies of Homo sapiens sapiens (anatomically modern humans).
Subspecies is either a taxonomic rank subordinate to species, or a taxonomic unit in that rank. Organisms that belong to different subspecies of the same species are capable of interbreeding and producing fertile offspring.
Neanderthals were also a subspecies of homo sapiens (homo sapiens neanderthalensis). This evidence proves they were capable of interbreeding with homo sapiens sapiens.
Don't you mean 'ethnicities'? There's only one race, the Human one. Every other distinction is local and only amounts to variation of the basic type.
And black Americans are interbred with whites, so they will in all probability have this haplotype as well.
When a kid we had a perverted dog that raped our tomcat.