Today, on a blog called Remote Central, I just came across a blog entry called "Human Evolution on Trial --- Neandertals", or something quite similar. You can read it all here. It's quite interesting, really, because the blogger seems to conclude that Neandertals hybridized themselves out of existence. Which may well be true. There doesn't seem to be any evidence of some innate "modern" superiority, nor does there seem to be any evidence that the two groups(assuming, for the sake of argument that they were, in fact, two separate species), that they had drifted apart, evolutionarily speaking, to not be, as geneticists put it, "interfertile". Which just means they could have offspring and their offspring could have offspring. There may be fossil evidence of this, though, like just about everything else concerning Neandertals, this is contested. And there's certainly no evidence that disease or mass estermination took place. Neither "modern" humans nor Neandertals, at the time they coexisted, seem to have lived in large enough groups for diseases to spread easily. And "moderns" didn't have a sufficently "superior" technology to exterminate them. Who knows? Maybe there's a little Neandertal in you, and you, and you, so to speak. I would like to thinks so(at least regarding some papulations.
In any case, this is (partly) an underlying theme in my Great Medieval Science Fiction Masterpiece With Neandertals, though some may find this idea to be pure "fantasy". And this is why I recommend reading this blog. Or, for that matter, read the blogger's whole series. You can learn about human evolution, should you desire to do so, quickly, easily, painlessly, and be entertained at the same time. What more can anyone ask?