> 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 keep

> 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.