GUEST POST: The History of Ashkenazi Jewry through the Prism of DNA
I promised you a few weeks ago that I would have a post on genetics and Jewish history. A bit delayed, but here it is, from Jon Entine, the author of Abraham's Children – Race, Identity and the DNA of the Chosen People.
Jon touches on the Khazars, the genetic origins of Ashkenazi Jews, Jews and IQ, and other hot button issues.
As always, the normal disclaimer for Guest Posts applies. The views expressed by the author of this post do not necessarily reflect my own.
The History of Ashkenazi Jewry through the Prism of DNA
By Jon Entine
It wasn’t surprising that in its end of the year issue, Science magazine named “human genetic variation” as the scientific breakthrough of the year. Science has moved out of the kum-ba-ya phase of genetic variation—the factoid that humans are 99 percent the same—to the reality that we are not only significantly different from person to person but that humans have evolved in populations, almost like pack animals, over the course of history. And in the center of that story is…
Despite being scattered to ends of the earth in the two millenia Diaspora, the once tribal religion of the ancient Hebrews has remained remarkably insular. Askhenazi Jewry, which has its roots in Central and Eastern Europe more than a thousand years ago, and still numbered as few as 25,000 people into the fourteenth century, are the most genetically distinct population of all. In my recent book, Abraham’s Children: Race, Identity and the DNA of the Chosen People I quote the estimate of Michael Hammer, the famous geneticist and Y-chromosomal expert, who believes that that the rate of non-Jews who entered the Ashkenazi Jewish gene pool over these many centuries was less than .5 percent per generation until recent decades. What does that mean? After all, Jews have paid a heavy price throughout history for being considered a race. They’ve been targeted for their religious beliefs and their cultural distinctiveness.
Scientists are studying group genetic variation because it offers the key to understanding the origins of diseases, which is the real focus of human genome research. The fact that scientists now acknowledge group-to-group differences should not be seen as resurrecting problematic racial theories. But it does mean we need a vocabularly to discuss human differences. This is particularly important to Ashkenazi Jews who are at the center of this debate.
Race is a taboo question to ask in this politically correct era but for Jews interested in the survival of the state of Israel, it must be confronted. Because the “right of return”––the principle that Jews have a right to immigrate to Israel and become citizens if they can verify Jewish ancestry—depends on it. In the age of DNA, we can now answer that question with some assuredness.
A walk through the geopolitical hazard zone known as the Internet finds untold numbers of screeds by anti-Israeli groups challenging the very premise of the right of return, claiming that Ashkenazi Jews are converts, so Jews have no ancestral, let alone Biblical, association with Israel. They base their inflammatory contentions on the writings of a Jewish journalist, Arthur Koestler, whose 30-year old book, The Thirteenth Tribe claimed that most European Jews were not Semites but descendants of Khazarians, part of the once-Jewish Khazarian empire whose nobility converted to Judaism during the late first millennium. The historical record was never clear about this, which left an opening for anti-Zionists like Koestler to turn their ideology into pop history. His book was embraced by some Jews and the general public. But its become gospel in many Arab circles, which contend that displaced Palestinians are the real native sons of the Levant.
What does the DNA say?
According to Hammer and numerous other scientists, Jewish and Christians, Jews are one of the most distinctive populations—a term scientists use rather than the folkloric notion of “race”—in the world. On our male side, approximately 70-80 percent of Ashkenazi Jews can trace their ancestry back to ancient Israel. A vast majority of Cohanim even trace back to one man who lived approximately 3300 years ago—perhaps Aaron, the first High Priest, if he indeed existed. DNA provides genetic witness to key stories in the Hebrew Bible and clearly rebukes Koestler’s thesis. As much as 20 percent of Ashkenazi Jews—me including—do have what might likely be Khazarian genes, which geneticists believes lead credence to the story of the conversion to Jewry of a tiny segment of the Khazarian population—the nobility. Many of them reportedly also were granted Levite status, which is a reasonable explanation for why half of all Levites have non-Jewish Khazarian origins.
Our maternal Ashkenazi lineage is more complicated and still to be fully unraveled. Israeli geneticist Doron Behar found that about 4 million of today’s Ashkenazi Jews ––about 40 percent of Jews originating in Central and Eastern Europe––descend from just four women. But as many as half of all Ashkenazi Jews might have as its founding mother a non-Jew, as Jewish traders plying the back roads of Europe took on local wives and then subsequently raised their children as Jews, sometimes without the new Jewish mother having undergone formal conversion.
The bottom line: Ashkenazi Jews are by the measure of population genetics one of the most distinctive populations in the world, which explains why there are so many “Jewish diseases” and (scientists speculate) why Ashkenazi Jews have the highest IQ of any population in the world as a consequence, some scientists believe, of both cultural and genetic factors. We are a genetic goldmine, as scientists peer into our genes to solve the mysteries of life and death.
Jon Entine is author of Abraham’s Children: Race, Identity and the DNA of the Chosen People and can be contacted here.