David Reich

So we often talk about the revolutionary events 50 to 100,000 years ago, the more symbolic behavior and so on and so forth, that sort of first appear in Africa and the Middle East and spread beyond.

But there's also this earlier event

And this event is sort of contemporaneous with the breakup of all the different groups also in Africa today.

You know, the Khoisan Southern Africans and the Central African Rainforest Hunter-Gatherers.

So one wonders whether this is an equally important formative event.

It also, if that's true, makes you think of Neanderthals as actually somehow our cousins, that they actually share our Y chromosome, they share our mitochondrial DNA, they share formation of this two or 300,000 year old event, their shared toolkit.

So even though the genome is telling us that they're cousins of Neanderthals, Denisovans, the actual correct way to think about them may be in an important sense somehow

the relations or the close cousins of modern humans.

So the genetic data suggests, this is analysis not of any ancient DNA, but only an analysis of modern DNA from different people, mostly in Africa, but also non-Africans.

And multiple studies, there's at least three, maybe four or five studies that I know about, have looked at the patterns of variation in people today and say the data in modern people today, including in Africans, is not consistent with a homogeneous population.

It looks like a population that's split

well more than a million years ago into multiple, at least two, but maybe many groups, and then came together with an important coming together a few hundred thousand years ago.

The papers have different models that they fit, but they all have this feature of more than a million years ago, there's a split up.

And then on the order of a few hundred thousand years ago, there's a coming together and a remixter event forming the ancestors of anatomically modern humans.

All of these groups have this.

Maybe it's in slightly different proportions.

So you ask, where are these people living?

Who knows, right?

Like, you know, in this scenario, the 80% is coming from the Caucasus or Northeast Africa.

where this Middle Stone Age form.