[SuperOne]

isnt there 2 theories on this: 1. we killed them off.
2. or we bred with them......>which explains the looks of some central europeans.

Or both??

[luvbach1]

Yes, they could have interbred with "modern humans." And this may account for the "caveman" looks of some Euros (not saying which they are!). And as you indicate, modern humans killing them off is another of the theories. But unexplained is how and why the all of the pure Neanderthals died off.