Jewish Heritage Written in DNA
The team also used its data to better understand the history of the Ashkenazi Jewish people through analyzing both level of similarity within Ashkenazi genomes and between Ashkenazi and non-Jewish European genomes. By analyzing the length of identical DNA sequences that Ashkenazi individuals share, the researchers were able to estimate that 25 to 32 generations ago, the Ashkenazi Jewish population shrunk to just several hundred people, before expanding rapidly to eventually include the millions of Ashkenazi Jews alive today.
Further, the researchers concluded that modern Ashkenazi Jews likely have an approximately even mixture of European and Middle Eastern ancestry. This suggests that after the Jewish people migrated from the Middle East to Europe, they recruited people from local European populations.
These results are compatible with those of prior work on mitochondrial DNA (mtDNA), which is passed on maternally. This prior work suggested that Ashkenazi men from the Middle East intermarried with local European women. The Ashkenazi population “hasn’t been likely as isolated as at least some researchers considered,” said Keinan.
Finally, the newly sequenced genomes shed light on the deeper history of Europe, showing that the European and Middle Eastern portions of Ashkenazi ancestry diverged just around 20,000 years ago.
“This is, I think, the first evidence from whole human genomes that the most important wave of settlement from the Near East was most likely shortly after the Last Glacial Maximum . . . and, notably, before the Neolithic transition—which is what researchers working on mitochondrial DNA have been arguing for some years,” Martin Richards, an archeogeneticist at the University of Huddersfield in the U.K., told The Scientist in an e-mail.
Skorecki noted that the new study demonstrates the utility of sequencing whole genomes of a more diverse set of people. “It is not clear to what extent this level of powerful inference will be reproducible in other population isolates with less dramatic or recent bottlenecks followed by expansions,” he said. “But with sufficient numbers of samples, parent population information, and computational analytic power, we can expect important and surprising utilities for personal genomic and insights in terms of human demographic history from whole genomes.”
Further, the researchers concluded that modern Ashkenazi Jews likely have an approximately even mixture of European and Middle Eastern ancestry. This suggests that after the Jewish people migrated from the Middle East to Europe, they recruited people from local European populations.
These results are compatible with those of prior work on mitochondrial DNA (mtDNA), which is passed on maternally. This prior work suggested that Ashkenazi men from the Middle East intermarried with local European women. The Ashkenazi population “hasn’t been likely as isolated as at least some researchers considered,” said Keinan.
Finally, the newly sequenced genomes shed light on the deeper history of Europe, showing that the European and Middle Eastern portions of Ashkenazi ancestry diverged just around 20,000 years ago.
“This is, I think, the first evidence from whole human genomes that the most important wave of settlement from the Near East was most likely shortly after the Last Glacial Maximum . . . and, notably, before the Neolithic transition—which is what researchers working on mitochondrial DNA have been arguing for some years,” Martin Richards, an archeogeneticist at the University of Huddersfield in the U.K., told The Scientist in an e-mail.
Skorecki noted that the new study demonstrates the utility of sequencing whole genomes of a more diverse set of people. “It is not clear to what extent this level of powerful inference will be reproducible in other population isolates with less dramatic or recent bottlenecks followed by expansions,” he said. “But with sufficient numbers of samples, parent population information, and computational analytic power, we can expect important and surprising utilities for personal genomic and insights in terms of human demographic history from whole genomes.”
Defining Jews, Defining a Nation: Can Genetics Save Israel?
How studies of Jewish DNA could help answer a question that's at the heart of some of Israeli society's biggest problems: Who counts as a Jew?
"Under the Law of Return, any Jew in the world may make aliyah and claim citizenship in Israel. The law extends the right to spouses and offspring of Jews who may not be Jewish themselves. However, if an immigrant wishes to marry, he or she may face obstacles. There is no civil marriage in Israel; the institution is controlled by a religious authority, the Rabbinate. According to halacha, ancient Jewish law, either the applicant's mother must be demonstrably Jewish (the blood connection) or else the applicant must have converted to Judaism in a verifiably Orthodox ceremony (the cultural test). If unable to satisfy the authorities, immigrants may get married outside the country, and the state will accept the union. Secular Israelis who resent the strictures go abroad by choice, nearby Cyprus often providing their version of the Las Vegas wedding."
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Jews Are a 'Race,' Genes Reveal
Geneticists have long been aware that certain diseases, from breast cancer to Tay-Sachs, disproportionately affect Jews. Ostrer, who is also director of genetic and genomic testing at Montefiore Medical Center, goes further, maintaining that Jews are a homogeneous group with all the scientific trappings of what we used to call a “race.”
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Welcome to the Tribe:
The DNA Chain of Tradition
The Discovery of the "Cohen Gene"
The Discovery of the "Cohen Gene"
