>Who aren’t Africans, but for the most part are of mixed background of Africans and Europeans in the last 500 years.

Again, broad pronouncements like this square... strangely... with my skin color and facial features. I think you'll find it a hard sell to much of this country, within and without the scientific community, that black African-Americans are not... you know, African. To an extent. For different reasons, depending on who you ask, of course.

>Which is why it’s odd anyone is getting defensive about it.

Assuming that you're an American, the notion that you don't understand the defensiveness strains credulity. It validates quite a bit more in the eyes of some.