This is my problem: what do we do about a thought experiment that is not convincing? I mean, you can agree with Sam’s take, but I hope a reasonable person can see how it’s not obvious that this would be controversial.

I mean, I personally would not care at all about the ancient underpinnings of any race’s human-like partners. My baseline expectation is that it happened a lot, and to the extent it didn’t... so what? Unless something absurd happened like cross breeding with birds and there’s a race of humans with a non zero chance of having wings. Our discovering ancient cross breeding with Neanderthals is not interesting. Had it been exclusively blacks, it would not be interesting either.

So I find this sort of thought experiment to be more neurotic than anything. It’s not an Einstein thought experiment, where you visualize the physics in play and it all comes together. It’s imagining a fairly inconsequential “revelation” being blown up into a devastating blow to race relations. It’s simply not obvious to me that this is how it would play out.