I agree that one thing like the absence of skeletons or the absence of cave art alone doesn’t necessarily indicate something that is definitive but when you take a bunch of those types of indications and put them together, they paint a picture that is, if not definitive, at least very compelling. That’s my point.

In my experience, “We just have no way to know” is a deflection to not have to interface with things that are inconvenient to acknowledge because they go against the speaker’s preconceived notions. I know that you are cautious by nature and not doing it for this reason, but it’s still a bit of a cop out. Yes, there are things that I personally do not know and do not even know that I don’t know, but when you take a body of work over time from a variety of sources, and from a variety of related disciplines, particularly when we a lot of really specific data such as this, the ability for things to be known related to it goes up exponentially:

“In 2016, research indicated that there were three distinct episodes of interbreeding between modern humans and Neanderthals: the first encounter involved the ancestors of non-African modern humans, probably soon after leaving Africa; the second, after the ancestral Melanesian group had branched off (and subsequently had a unique episode of interbreeding with Denisovans); and the third, involving the ancestors of East Asians only.[43]”

If we don’t accept this — that “crowdsourcing” by scientists from various disciplines over time tells us anything substantive, then anything at all is possible or impossible and there is no sense even talking about any of it, which is frankly, just kind of stupid.