David Reich

But this would be even bigger.

So what you would expect to see is that as this group spread,

they would be moving into a territory full of archaic humans, and there would be some interbreeding, but the kids would be not very fit.

They would die off.

There would be a lot of infertility.

And so the barriers to gene flow and to interbreeding would be greater.

So to me, it's not at all surprising that as this group moves into Eurasia, here's Eurasian archaics.

you know, the ancestors of Denisovans.

You know, and these are only 400,000 years diverged from these people over here.

And here's African archaics.

And these are like 1.2 million years diverged.

So, you know, they just don't interbreed as much.

And so you don't get as much gene flow.

But the key thing is at the same time.

It's the same time.

So, like, it really feels like the signature of an explosion of people from one place interacting with people here, interacting with people here.

It's the same sort of

sort of cultural revolution or technological revolution impacting this place, impacting this place.

And creating populations that are kind of both impacted by this cultural revolution, which we know is the case because they share the same toolkit.

And so, you know, some people argue that level law technology is independently invented, but this would be a sort of, but, you know, it's very similar.