David Reich

So that genetic combination in West Eurasia has been pushed down again and again over the last 10,000 years under the pressure of natural selection, without a doubt, in its action on many, many independent genetic variants, all pushing in the same direction and overwhelmingly

statistically significant way.

So one possible interpretation of this, and this is speculative, is that you're shifting from a mode of survival that's more feast and famine to one where food is more regular and it's not as advantageous to store fat.

And so there's selection against sort of fat storage.

Well, on a timescale, I mean, selection acts, I don't know how you think selection acts, but at some level, it could be terrible on the individual level and good on the population level.

So I think that, you know, I'm not doubting the evidence that you're, I think, maybe referring to, which is that skeletally, there's a lot more sort of skeletally unwell people.

Yeah.

associated with the beginning of agriculture than there are in the hunter-gatherer period.

I think on an individual level, life could have been experienced more harshly, but in terms of survival, different animals have strategies of investing less in their young, but having many more young, or investing more in their young and having

you know, fewer young and maybe the hunter-gatherer strategy might be the latter and the farmer strategy might be having more young and some of them survive longer or something, more of them survive.

And on average, over a lifetime, there might be a stable enough food that if you don't rely on such adaptations, it might be better.

Yeah.

So that's super interesting.

And I'm going to back up a little bit because in my book, I have a section where I describe when we had these findings for the first time and the conversations we had with archaeologists about these findings.

So ancient DNA has been very disruptive to conventional understanding of the past.

And what happened when we had these findings of massive disruption of the local population in Germany about 45 to 4700 years ago, based on arrival of people from the steppes north of the Black and Caspian Sea, was some of our archaeologists, co-authors, really just were very distressed by the implication.

Because after the Second World War, there had been a reaction where people said this initial idea that people had, based on archaeology, where in the beginning of the 20th century, when people would see new types of pots in a certain layer of the excavation, they would argue that this is the arrival of a new people coming through...

invasion or through movement into a region and it's very disruptive event, the arrival of the Corded Ware Complex or the arrival of the Bell Beaker Complex or something like this.

This is a very disruptive event mediated by invasion or so on.

And that was used by, for example, the Nazis to argue that these were spreads of Aryans moving across the landscape and being very disruptive and violent, for example.