David Reich

at the genetics, the whole genome, the Neanderthals and Denisovans cluster.

But if you look at the mitochondrial DNA, which people get from their moms and they get from their moms, Neanderthals and modern humans cluster.

So if you look at the mitochondrial DNA, Denisovans and modern humans share an ancestor well more than 700 or 800,000 years, as you expect from the history.

And if you look at the Y chromosome that you get from your dad,

Denisovans and modern humans share an ancestor more than seven or 800,000 years ago, which is consistent with this history.

But if you look at the Neanderthal mitochondrial DNA, it's only three to 450,000 years.

If you look at the Y chromosome, it's only three to 450,000 years.

So what the current genetic work is asking us to believe is that even though this is only 5% of the whole genome, it introduces mitochondrial DNA and Y chromosomes and they jump up to 100% frequency.

It's kind of a crazy claim because the probability of this occurring by chance is low, maybe 5% times 5%, so a very small number.

And so it's sort of what we actually all believe, but it's sort of a very sort of surprising event.

And somehow it's accreted all the findings in the whole literature so that we make ourselves believe this, but it seems sort of

unlikely on first principles that somehow only 5% will introduce both the Y chromosome and mitochondrial DNA.

And it really looks like this.

So there's this amazing data from this site in Spain that's like two to 400,000 years old.

It's three to 400,000 years old at a site called Cima de los Huesos.

And they have a nuclear genome that looks Neanderthal-like,

most of the genome, but their mitochondrial DNA and Y chromosome was Denisovan-like.

So it really looks like there was a population related to modern humans that pushed into this Sema de los Huesos-like population, displaced its mitochondrial DNA and Y chromosome, but kept the rest of its genome.

So it really looked like something like this happened.

So the idea that I'm sort of playing with, and probably it's wrong, who knows, but is that there's a landscape, this is maybe Europe, and