[calex59]

Talk about your unscientific approach. What this guy is saying is that despite the lack of concrete evidence he "knows" Neanderthals and Homo Sapiens had sex. I wouldn't doubt that horny hunters on an extended hunt who came across Neanderthals had sex with their women, but you can't say you "know" something when you only strongly suspect it.

If they did have sex and the off spring were like mules and couldn't reproduce this could, in part, account for the extinction of the Neanderthal, however there would be no way of proving this because the DNA would have been lost.

[Varda]

Yes he’s drawing a conclusion with a complete lack of evidence. There are no hybrid fossils either. All the suspected hybrid fossils have turned out to be modern humans.