Does David Reich contradict Nicholas Wade?

[sevensages]

Last year I read Nicholas Wade's book Before the Dawn. Before the Dawn is about the history of humanity in prehistoric times.

I am currently reading David Reich's book Who We Are and How we Got Here. Who we Are and How we Got Here is also about the history of humanity in prehistoric times.

In Before the Dawn, Wade wrote the following: "The Richards team's reconstruction of the population history of Europe brought to light an unexpected fact: that most Europeans are descended from the first settlers who arrived during the Upper Paleolithic Era. Only a minority arrived during the Neolithic age."

In Who We Are and How We Got Here, David Reich wrote the following: "The extraordinary fact that emerges from ancient DNA is that just five thousand years ago, the people who are now the primary ancestors of all extant northern Europeans had not yet arrived" (107).

Is it just my imagination, or does the quote by David Reich contradict the quote by Nicholas Wade? If the two quotes don't contradict each other, please reconcile them for me. I don't see how those two quotes don't contradict each other.

If there is a contradiction, I suppose the consensus is probably that David Reich is correct since David Reich had access to ancient DNA that Nicholas Wade did not have access to. Who We Are and How we Got Here was published in 2018. IIRC, Before the Dawn was published circa 2006.

If there is a contradiction, is the consensus among geneticists that Reich's assertion is correct and Wade's assertion is false?

 

[Andrew Mason]

There is a difference, not necessarily a total contradiction. Based on genetic analysis of European skeletons older than 5000 years, inhabitants of Europe before about 3000 BC had mixed genes from hunter-gatherers and Anatolian farmers. Both authors agree on that. Hunter-gatherers arrived in the upper paleolithic (around the end of the ice-age 15000-10000 years ago) and Anatolian Farmers arrived in the early neolithic period about 7,000-9,000 years ago from what is now Turkey.

According to Reich the genetic evidence is that most modern Europeans are descended from migrants from the steppe regions of eastern Europe and Asia beginning about 5,000 years ago. Reich estimates Europeans today have genes that are 75% Steppe and 25% hunter-gatherer / Anatolian farmer.

The issue seems to be the size of the Steppe migration and, possibly, the extent to which the Steppe arrivals mixed genes with the hunter-gatherer and Anatolian farmer locals. The genetic data that establishes the wave of Steppe migration beginning around 3000 BC was not available in 2006 when Wade published "Before the Dawn".

Wade uses limited DNA evidence done in the early 2000s - mainly of Y chromosomes and mitochondial DNA - to reach his conclusion that most modern Europeans can trace their ancestry back to the hunter-gatherers. But he was certainly aware there had been later migrations.

It should be noted that Wade is not a geneticist. He is a science writer who worked for the New York Times. Reich, who is a geneticist, used a lot more genetic evidence and more recent data, to reach his conclusions.

AM