They're not unreasonable assumptions. Especially considering that there is evidence of interbreeding between homo sapiens and neanderthals. There's DNA evidence, and now there's fossil evidence. If they're genetically somewhat compatible, it seems likely that it would have happened, and not really a good reason why it wouldn't.
Basically for every discovery of a possible human ancestry, we will need evidence of interbreeding, we can't just assume off course they all interbred. That's not science.
So this evidence is relatively new, in 2010 we found modern humans have about 2% DNA, and now we found a fossil teeth that appears to have hybrid characteristics.
My second issue is with people making assertions like: well off course probably they were tribal and at war with each other and would have a tradition of keeping the females of their enemies. Or off course they would have been attracted physically to each other. Etc.
We can all make up whatever explanation we want to believe in, that does not make it true. We'll similarly need to slowly unravel evidence that points towards those explanations to get an accurate understanding. And I was simply saying this new teeth discovery gives us no insight into this. So it seems we still don't know why they'd have interbred, how common it was, if all occurrence could successfully lead to offspring, when it would have started to happen, etc.
> My second issue is with people making assertions like: well off course probably they were tribal and at war with each other and would have a tradition of keeping the females of their enemies. Or off course they would have been attracted physically to each other. Etc.
I totally agree there. Don't assume too much about circumstances and lifestyles that we don't know about. Although I think that line was mostly a list of speculative examples, and not intended as a definitive explanation.
But given humans, it's not too crazy to assume some of them will have sex. And given that we've known for about 10 years that some humans (Europeans especially, I believe) have some small amount of Neanderthal DNA, clearly they did, and were at least somewhat interfertile.
