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.