Who Are the Jews? Genetic Studies Spark Identity Debate
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Ashkenazi JEWISH DIASPORA GROUPS Middle Eastern Sephardic Far-fl ung family. Ethiopian Jews (left) are geneti- cally distant from others but observe Jewish customs. Indeed, the Ostrer study found that Ash- kenazi Jews were as closely related to each other as fourth or fi fth cousins, even though HUMAN GENETICS their genetic profi les indicated between 30% and 60% admixture with non-Jewish Europe- ans. Jewish groups also clustered tightly with Who Are the Jews? Genetic Studies non-Jewish Middle Eastern populations such as the Druze and the Cypriots, strongly sug- Spark Identity Debate gesting an origin in that geographic region. “I would hope that these observations would put The world’s 13 million Jews are strongly make up 90% of American Jews and nearly the idea that Jewishness is just a cultural con- (NOVEMBER 2001) linked by religion and culture. But do they 50% of Israeli Jews. Tel Aviv University histo- struct to rest,” Ostrer says. 2 , share a common genetic heritage? Two rian Shlomo Sand’s 2008 book The Invention The Behar study also included three Jew- on June 11, 2010 new studies conclude that most members of the Jewish People argued that few modern ish groups whose ancestry has been uncer- GENETICS of the far-fl ung Jewish Diaspora can trace Jews can trace their heritage to ancient Israel. tain: the Beta Israel Jews of Ethiopia, the their roots to ancestors who lived in the He in part resurrects a thesis, made famous Cochin Jews of southern India, and the Bene Middle East more than 2000 years ago. The by writer Arthur Koestler in the 1970s, that Israel Jews of northern India. It found that new research, based on recent advances in Ashkenazi Jews are actually descended from all three groups genetically clustered with genome technology, apparently refutes con- a Turkic people in Central Asia whose rulers non-Jewish Ethiopians and Indians rather REVIEWS NATURE troversial claims that most of today’s Jews converted to Judaism in the 8th century C.E. than with the Diaspora groups. However, descend from more recent converts. And it The new studies contradict that conclu- analysis of the Y chromosomes of the Bene www.sciencemag.org fi nds that Jews in Ethiopia and India who sion. Both teams used DNA microarrays Israel Jews showed paternal links to the Mid- also claim origins in ancient Israel are more to examine variation within Jewish groups dle East, suggesting that they might share distantly related to other Jewish groups. Yet worldwide and between those groups and ancient roots with Jews from that region. some researchers argue that although sci- non-Jewish populations. Microarrays allow So it’s possible, Behar and other research- ence can track Jewish ancestry, it has little to comparisons of thousands of genetic differ- ers say, that the Ethiopian and Indian Jew- say about who is a Jew today. ences, from single nucleotide pairs to longer ish groups were founded by Jews from other The studies “clearly show a genetic com- stretches of DNA, between different individ- regions who then intermarried and/or con- mon ancestry” of most Jewish populations, uals (Science, 21 December 2007, p. 1842). verted many local non-Jews to Judaism, thus Downloaded from says Sarah Tishkoff, a geneticist at the Uni- This genomewide approach is much more expanding their numbers but diluting their versity of Pennsylvania, thus indicating a dis- powerful than previous analyses of Y chro- Jewish genetic signatures. tinct Jewish people through history. Indeed, mosomes and mitochondrial DNA, which Overall, “these results confi rm the com- says Harry Ostrer, a geneticist at New York were often inconclusive. mon wisdom that Jews have always held,” University Medical School and leader of one The Ostrer team analyzed nuclear DNA that they stem from a common Middle East- of the teams, the genomewide scans used from 237 Jews representing the three main ern origin and heritage, says historian Anita in the studies can detect Jewish ancestry in Diaspora groups: Ashkenazi Jews; Sephardic Shapira, also from Tel Aviv University. “It is anonymous DNA samples. But Doron Behar, Jews from Spain and Portugal; and Middle nice to get support from modern genetics, a geneticist at the Rambam Health Care Cam- Eastern, or Oriental, Jews. Their DNA was which refutes [Sand’s] assertions,” she says. pus in Haifa, Israel, and lead author of the compared with that of about 2800 presum- Sand counters that the whole concept of second report, argues that genes do not neces- ably non-Jewish people from around the identifying Jews genetically is fallacious. sarily make the Jew. There is no “metaphysi- world. The Behar study employed smaller “No study … has succeeded in identifying a cal” difference between someone born Jewish sample sizes—121 Jews and 1166 non- genetic marker specifi c to Jews,” he insists. and a convert to Judaism, Behar says. Jews—but from more population groups He adds, “It is a bitter irony to see the descen- The two studies—one led by Behar and and also analyzed 8000 non-Jewish Y chro- dants of Holocaust survivors set out to fi nd a published online this week in Nature, and mosomes and 14,000 mtDNA genomes. biological Jewish identity. Hitler would cer- Ostrer’s, published last week in The American The studies came up with very similar tainly have been very pleased.” But Ostrer Journal of Human Genetics—speak to a cur- results: Jews from the three Diaspora groups says that Sand has not kept up with advances rent debate about Jewish origins, including were closer to each other genetically than to in genetic research: “We can tell who the that of the Ashkenazi Jews of Europe, who non-Jews from the same geographic region. Jews are genetically.” –MICHAEL BALTER ON BEHALF OF JEWISH ETHIOPIA/WIKIMEDIA COMMONS; ADAPTED FROM H. OSTRER, CREDITS (LEFT TO RIGHT): THE ISRAELI ASSOCIATION 1342 11 JUNE 2010 VOL 328 SCIENCE www.sciencemag.org Published by AAAS.