For more than a century, Jews and non-Jews alike have tried to define the relatedness of contemporary Jewish people. Previous genetic studies of blood group and serum markers suggested that Jewish groups had Middle Eastern origin with greater genetic similarity between paired Jewish populations. However, these and successor studies of monoallelic Y chromosomal and mitochondrial genetic markers did not resolve the issues of within and between-group Jewish genetic identity. Here, genome-wide analysis of seven Jewish groups (Iranian, Iraqi, Syrian, Italian, Turkish, Greek, and Ashkenazi) and comparison with non-Jewish groups demonstrated distinctive Jewish population clusters, each with shared Middle Eastern ancestry, proximity to contemporary Middle Eastern populations, and variable degrees of European and North African admixture. Two major groups were identified by principal component, phylogenetic, and identity by descent (IBD) analysis: Middle Eastern Jews and European/Syrian Jews. The IBD segment sharing and the proximity of European Jews to each other and to southern European populations suggested similar origins for European Jewry and refuted large-scale genetic contributions of Central and Eastern European and Slavic populations to the formation of Ashkenazi Jewry. Rapid decay of IBD in Ashkenazi Jewish genomes was consistent with a severe bottleneck followed by large expansion, such as occurred with the so-called demographic miracle of population expansion from 50,000 people at the beginning of the 15th century to 5,000,000 people at the beginning of the 19th century. Thus, this study demonstrates that European/Syrian and Middle Eastern Jews represent a series of geographical isolates or clusters woven together by shared IBD genetic threads...
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Genes Set Jews Apart, Study FindsThose of European descent are more closely related with one another than with their fellow countrymen, say researchers who were primarily studying genetic diseases.
Jews of European descent living on opposite sides of the globe are more closely related to one another than they are to their fellow countrymen, according to the largest study ever conducted of what it means genetically to be Jewish. Ashkenazis, the primary group descended from European Jews, are all as closely related as fourth or fifth cousins would be, the study found...
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Tracing The Roots Of Jewishness
Who are the Jews? For more than a century, historians and linguists have debated whether the Jewish people are a racial group, a cultural and religious entity, or something else. More recently, scientists have been weighing in on the question with genetic data. The latest such study, published today in the American Journal of Human Genetics, shows a genetic connection among all Jews, despite widespread migrations and intermarriage with non-Jews. It also apparently refutes repeated claims that most Ashkenazi Jews are descended from Central Europeans who converted to Judaism 1000 years ago.
Historians divide the world's 13 million living Jews into three groups: Middle Eastern, or Oriental, Jews; Sephardic Jews from Spain and Portugal; and Ashkenazi Jews from Europe. Although the Bible traces Jewish roots back to the time of Abraham some 4000 years ago, most historians have concluded that the actual Jewish identity dates to only a little over 2000 years ago.
The origins of today's Jews have been less clear, especially those of the Ashkenazis, who make up 90% of American Jews and nearly 50% of Israeli Jews. Ashkenazi Jews settled in Germany in the 9th century C.E. and developed their own language, Yiddish. Some writers, notably Arthur Koestler in his 1976 book The Thirteenth Tribe, have argued that the Ashkenazis stem from a Turkic tribe in Central Asia called the Khazars, who converted to Judaism in the 8th century. And historian Shlomo Sand of Tel Aviv University in Israel argues in his book The Invention of the Jewish People, translated into English last year, that most modern Jews do not descend from the ancient Land of Israel but from groups that took on Jewish identities long afterward...
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Different communities of Jews around the world share more than just religious or cultural practices — they also have strong genetic commonalities, according to the largest genetic analysis of Jewish people to date.
But the study also found strong genetic ties to non-Jewish groups, with the closest genetic neighbours on the European side being Italians, and on the Middle Eastern side the Druze, Bedouin and Palestinians.
Researchers in New York and Tel Aviv conducted a genome-wide analysis on 237 individuals from seven well-established Jewish communities around the world, hailing from Iran, Iraq, Italy, Greece, Turkey, Syria and eastern Europe. The team then compared these genetic profiles to those of non-Jews in the same geographic regions based on data from the Human Genome Diversity Project, a database of genomic information for individuals from populations worldwide. Each group of Jews is genetically distinct, but similarities between the groups weave them together with what the researchers describe as "genetic thread".
"There has been this back and forth discussion over the course of a century or more — are these a people? Is this in the genome?" says Harry Ostrer, a geneticist at New York University, the study's lead author. The new findings, he says, show that there "does seem to be a genetic basis to Jewishness".
Several studies in the past decade have looked at the genetics of Jewish populations, using smaller numbers of individuals, or focusing on markers in mitochondrial DNA — which is passed down maternally — or on the Y chromosome, inherited paternally. The genetic ties identified in the present study, published in the June issue of the American Journal of Human Genetics 1, are consistent with the results of previous work, says Sarah Tishkoff, a human geneticist at the University of Pennsylvania in Philadelphia, "but this is, I would say, the first study to put everything together into a big picture by looking at a large number of sites in the nuclear genome"...
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Scientists taking a genomewide view of ancestry have traced the genetic roots of seven Jewish groups.
The study examines genetic markers spread across the entire genome — the complete set of genetic instructions for making a human — and shows that the Jewish groups share large swaths of DNA, indicating close relationships. Comparison with genetic data from non-Jewish groups indicates that all the Jewish groups originated in the Middle East. From there, groups of Jews moved to other parts of the world in migrations collectively known as the Diaspora.
Maps of those migrations were inscribed in the DNA in the form of genetic signatures of local people Jews interbred with as they moved. Today, contemporary Jews carry evidence of their Middle Eastern origin along with genetic heritage from European and North African ancestors.
“I like to think of relatedness as a tapestry, and these shared segments [of DNA] are threads in the tapestry,” says Harry Ostrer, a geneticist at New York University School of Medicine and the leader of the study, published online June 3 in the American Journal of Human Genetics.
Each of the Jewish groups (Iranian, Iraqi, Syrian, Italian, Turkish, Greek and Ashkenazi) has its own genetic signature but is more closely related to the other Jewish groups than to non-Jewish groups, the researchers found. Even though the researchers took care to exclude from the analysis people known to be directly related, any two Ashkenazi Jewish participants in the study shared about as much DNA as fourth or fifth cousins, Ostrer says.
Better understanding the genetic heritage of individuals may help researchers zero in on disease genes that are more common in certain ethnic groups, he says. For instance, many Ashkenazi Jewish women are at high risk of developing breast cancer, even though the women often don’t carry versions of genes known to be linked to breast cancer.
Previous studies of Jewish heritage using parts of the genome inherited only from the mother or father have reached similar conclusions, but the new study examines the entire set of genetic blueprints, allowing researchers to uncover contributions from many ancestors at once...
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How Religion Made Jews Genetically Distinct
Jewish populations around the world share more than traditions and laws – they also have a common genetic background. That is the conclusion of the most comprehensive genetic study yet aimed at tracing the ancestry of Jewish people.
In a study of over 200 Jews from cities in three different countries, researchers found that all of them descended from a founding community that lived 2500 years ago in Mesopotamia.
Harry Ostrer of New York University, whose team carried out the study, likens modern Jewish populations to a series of genetic islands spread across the world.
The main reason that Jews continue to form a distinct genetic group, despite their wide dispersal is the exclusivity of the Jewish religion and the tight restrictions it imposes on marriage to those outside the Jewish faith.
Ostrer's colleague Gil Atzmon of Albert Einstein College of Medicine at Yeshiva University in New York says that the religious traditions and laws shared by practising Jews around the world, and their isolation from their non-Jewish neighbours, means that Jews share many more genomic segments with each other than they do with non-Jewish people...
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The Thirteenth Tribe by Arthur Koestler
The Invention of the Jewish People
