Including the beard.
There was an interesting article I read once out of Hungry, where the researcher remarked that no one claims Neanderthals are part of their DNA, but all claim they are part of everyone else’s.
Basically, the Neanderthals were a racial sub type. If they could breed in, they were not separate species. If they were, the children of such unions would more than likely be sterile.
If there is a "debate" here, it may only be over definitions of words -- what, exactly, is a species, sub-species or 'racial sub-type'?
Consider that horses and cows cannot reproduce, period, so by any definition, they are separate species.
Horses and donkey's produce mules, which themselves cannot reproduce, and so again by definition, the parents are also separate species.
But now consider various "species" of, say, zebras (Plains, Mountain & Grevy's) which can produce viable offspring -- and yet they are still considered separate species.
So the question is, by what definition?
If different species can produce viable offspring together, then how are we even calling them "species"?
The same would hold true for pre-human species, of which the fossil record identifies nearly two dozen.
Were some of them biologically close enough to have produced viable offspring?
And if so, why are we still calling them separate species?