David Reich

I know this is true also of several other laboratories in the world now.

And this huge jump in data, this sort of semi-exponential or even super-exponential jump in some cases, has made it possible to ask and answer questions.

So while they were only on the order of 10 genome sequences from humans in 2010, this year it's passed more than 20,000 reported sequences.

So there's several orders of magnitude increase.

And the questions we were able to ask in 2014 are just not the same as the ones we can ask today.

Thank you.

Thank you, Dorkesh.

Well, I think what's very interesting is that what we have data from now are modern humans, the sequences of people living today.

And we also have data from Neanderthals who are archaic humans who lived in Western Eurasia for the last couple of hundred thousand years.

And we have now sequences from many Neanderthals.

And we also have DNA from Denisovans.

Denisovans are archaic humans who were discovered from the DNA.

from a finger bone that was found in a cave in Siberia, not anticipated to be a new group of humans, but were sequenced.

So we have DNA from these different sources plus bits of DNA from these sources mixed into modern populations.

And based on this, in the last 10 years or 14 years, we collectively have been piecing together an understanding of how

modern humans are related to our closest relatives who are now no longer with us in unmixed form, the Neanderthals, Denisovans, and maybe others who are no longer, not yet sampled.

And the model that we have is really a model based on accretion.

So we start with the modern humans and then we add the Neanderthals once we obtain that sequence and we add the Denisovans.

And then the model doesn't quite fit and we add...

other mixture events to make the model fit.