How do we know that Neanderthal skeletons are Neanderthal skeletons?

[Jehanne]

What I find interesting is that, outside of Africa, all H. Sapiens have a small amount (a few percent) of H. Neanderthalensis DNA.  What this proves is that H. Neanderthals were developing as a divergent species of Homo, the sexual relations between H. Sapiens males and H. Neanderthal females likely not being consensual, probably occurring after the murder and massacres of H. Neanderthal males by H. Sapiens.

Once you go neanderthal, you'll never go back.  

that’s reading way too much into it.  the genetic separation of HN and HS certainly results from mostly from geographic isolation.  that does not imply the eventual re-encounter is necessarily more hostile or violent than what would be typical between two groups of previously unacquainted HS groups.

Plenty of Neanderthal skeletons show evidence of violence at the time of death. It's reasonable that we killed them off, committing some rape in the process.