Q&A: Tracing Jewish history through genes

By STEVE SAILER, UPI National Correspondent
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LOS ANGELES, May 15 (UPI) -- Surveys show that somewhere between 33 percent and 52 percent of all Jewish-Americans are now marrying gentiles. This is causing worry in some parts of the Jewish community about the long-term survival of Jews, at least outside Israel, as a coherent people.

As the public intellectual Irving Kristol has joked, the main threat to Jewish identity in the West today comes not from the desire of Christians to kill Jews, but from their desire to marry them.


Elliott Abrams, who is now the White House's senior director for Middle Eastern affairs, spent much of the past decade working to alert American Jews to the danger posed by their marrying non-Jews. In 1997, he wrote:

"Intermarriage is both inevitable in our open society, and immensely threatening to Jewish continuity here ... Despite the hopes of many in the Jewish community, the effect of mixed marriages on children is evident. Only 28 percent are raised as Jews, and an even smaller percentage marry Jews...


A three-generational study of Jews in Philadelphia found that no grandchildren of mixed marriages continued to identify as Jews."

From a historical perspective, however, this current era of Jews marrying gentiles is not unique, according to author Jon Entine. While other peoples have come and gone over the millennia, the world Jewish community has survived both through eras of horrific persecution and eras of high rates of intermarriage. Today's Jews are almost all the descendents of that core of past Jews who raised their children within the faith and the community.

Entine, a southern California science journalist, is writing a book on Jewish history with the working title of "From Abraham's Seed: How Genetic Research is Unlocking the Story of the Bible and the Unique History of God's Chosen People." It's slated for publication in spring 2004 by Gotham Books, an imprint of Penguin/Putnam.

He took time to answer United Press International's questions:

United Press International: How did you decide to write about Jewish history from the perspective of the new genetic studies?

Entine: It flows directly out of two experiences: being hopeless in fulfilling my one ambition growing up, to be a professional football player; and the trauma of my bar mitzvah. The first led me in part to write a book in 2000 on the genetics of race and sports called "Taboo: Why Black Athletes Dominate Sports and Why We're Afraid to Talk About It." Of course, "Taboo" was less about sports (and my intrinsic athletic shortcomings) and more about the historical debate over "human biodiversity," or racial differences.


It only seemed logical to extend that inquiry into other areas where genetics and culture collide. I grew up being inculcated with the pervasive, if unspoken, Jewish belief that we were indeed a chosen race, a special people. What more exciting subject than the study of the racial group that is perhaps mankind's most ancient -- the Jews?

There are few issues more intriguing than our own histories: Who are we? What are our origins and seminal beliefs? Until recently, the Bible was the primary source for clues about the origins and migrations of early western civilization. Now, genetic technology is also helping us better understand both our shared origins and our differences.

Racial identity, the notion that being Jewish is something beyond culture and extends to blood, is a fascinating -- if taboo -- subject. Like a moth to a flame, it draws my interest.

Q: Wouldn't humanity be best off not knowing about such sensitive topics?

A: I suppose one could concoct an argument for why scientific or religious inquiry should be censored. There are always zealots who claim to want to protect the unwashed from potentially "dangerous ideas." Certainly, a few critics reviewing "Taboo" argued against airing the subject of human differences, claiming that the issue was too complicated for popular discourse and therefore even posing questions about genetics fans mistrust.


The thorny reality, however, is that frequencies of many "polymorphic" genes vary with population clusters and can have powerful health consequences. Genetic factors help explain the prevalence of Tay-Sachs, a neurological disease, among European Jews, and the proclivity to skin cancer and cystic fibrosis among northern Europeans.

These are all "racial" differences of a kind; potentially thousands more remain to be identified. Humanity is in the early stages of a biotechnological revolution that is transforming our understanding of human nature -- the commonalities that bind us and the differences that confer uniqueness. To suggest we shouldn't explore such research is criminal.

Q: Why are geneticists studying Jews in particular?

A: There's of course a cultural component to this research. Although Jews represent a tiny and vulnerable minority in the world population -- 15 million people, or a little over 0.2 percent -- they have had a disproportionately important impact on Western culture. Their religious beliefs underlie the world's three great monotheistic religions.

From a scientific perspective, Jews are a genetic goldmine. The question of identity has always been central to Jews' self-understanding. Biblical literalists have long contended that Jews are a "race apart," citing Deuteronomic Law: "You shall not intermarry with them (non-Jews)." As a result, some Jewish populations, such as the Ashkenazi from Eastern Europe, are among the more genetically distinct in the world, a fact even more remarkable because, unlike almost all other groups, they did not live in a geographically limited area but were dispersed throughout the world.


Scientists are learning that rare differences from person to person and group to group hold clues to medical mysteries. Small, reproductively isolated genetic islands show diseases and traits marked by unusual gene frequencies known as haplotypes. It is only from knowledge of "gene pools" that we can hope to reconstruct the evolutionary history of humanity and develop treatments for many medical problems.

While many groups are currently being studied -- the Finns, the Ainu, the Amish, American Indians, and Icelanders, among others -- Jews of central and eastern European ancestry, known as Ashkenazim, are among the most promising subjects.

Q: Are Jews a "pure race" descended unchanged from the early days of the Bible?

A: No. Like all human populations, they've married outside the group at times. The first signs of it are in the Bible itself. For example, the wives of Jacob's 12 sons included a Canaanite and an Egyptian. Moses married a Midianite woman and then a Cushite. Samson married a Philistine. At least two non-Israelite female ancestors figured in King David's genealogy. Mixed marriages between Samaritans and Judaites were common.

Q: Have there been earlier eras similar to this one in which many Jews married gentiles and their descendents tended to be gentiles?


A: Yes. For example, during the Hellenistic period after Alexander the Great's conquests, Jewish intermarriage with gentiles was rampant. There was definitely a net "outflow" of Jews from the religion, yet Hellenized Judaism survived.

Q: Were there times when Jews married gentiles, but the children tended to remain within the faith?

A: Under the Roman Empire, the Jewish community in Italy was quite sizable for a time, with lots of flow in and out. During the early Christian period in the Roman Empire, Jewish males who had left the Mideast often took on Gentile wives. Their offspring probably became the core of Ashkenazi Jewry.

However, some time around the fall of Rome is when the taboos on intermarriage (imposed by both Jews and Gentiles) became stringent. The real end to Ashkenazi Jewish out-marrying did not come until the Middle Ages as the economic and social position of Jews worsened considerably.

This historical trend is reflected in the genetic data, which suggests that the genetic core of modern Ashkenazi Jewry was not formed until this period. The core consisted mostly of Jewish men with Middle Eastern roots marrying a high percentage of local Gentile women, then forming Jewish communities.

Q: Is that when the rule switched and membership in the Jewish community became no longer a function of one's father being a Jew, but of one's mother, which tended to cut down on outmarriage?


A: As economic and social pressures mounted, that mixed group evolved to become the Ashkenazi Jewish core, with almost no intermarriage with Christians ... less than one half of 1 percent per generation, geneticists estimate.

In the 19th century, however, the position of western European Jews improved considerably, leading again to a fair amount of intermarriage, particularly in German-speaking areas. This reflected the decline of orthodoxy and the birth of Reform Judaism.

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