Re: Many mysteries
"But we don't consider Dogs & Wolves to be the same "race" but they can interbreed too... No?"
The genetic variation of dogs and wolves is much greater than for humans.
Also, you missed my point. I did specifically refer to population isolation. Neanderthals and Denisovans were genetically distinct populations even though they could interbreed. We can call them races if you like. But we're only about 2% Neanderthal, so that doesn't even start to apply. The current human race is much less genetically varied than the total of Sap. + Neanderthals + Denisovans.
Which is why these things are so difficult to identify.
One of the interesting things about racism is the way it focusses on skin colour but not hair colour.