So 30,000 years ago there were two human species on earth - us and the Neanderthals. The Neanderthals never reached a very big population and could not survive as we could, theoretically due to lack of an ability to communicate and work as a team as we did in a more hostile environment. But what if they could have just held on a while longer? Maybe then we would have sensitive to their plight and felt like "human rights" applied to them too. I'll bet there would still be problems like kids making fun of them and stuff. Choirs would be walking in the snow singing and they would try to join in and just grunt real loud. We'd try to be polite, but come on, that would get old! We don't even do well among our own species so I know damned well we'd not put up with that shit!
Maybe they're better off as fossils. Just a thought.