Ashkenazi Descent Is Traced

About 3.5 million of today’s Ashkenazi Jews -- about 40% of the Ashkenazi population -- are descended from four women, a genetic study indicates.

Those women apparently lived somewhere in Europe within the last 2,000 years, but not necessarily in the same place or even the same century, said lead author Dr. Doron Behar of the Rambam Medical Center in Haifa, Israel.

Each woman left a genetic signature that showed up in their descendants today, he and colleagues said in a report published online by the American Journal of Human Genetics.

Together, their four signatures appear in about 40% of Ashkenazi Jews, but are virtually absent in non-Jews and found only rarely in Jews of non-Ashkenazi origin, the researchers said.

They said the total Ashkenazi population was about 8 million people. The world Jewish population is about 13 million.

Ashkenazi Jews are a group with mainly Central and Eastern European ancestry. Ultimately, though, they can be traced to Jews who migrated from Israel to Italy in the first and second centuries, Behar said.

Eventually this group moved to Eastern Europe in the 12th and 13th centuries and their population boomed, reaching about 10 million just before World War II, he said.

The study involved mitochondrial DNA, or mtDNA, which is passed only through the mother. A woman can pass her mtDNA to grandchildren only by having daughters.

So mtDNA is “the perfect tool to trace maternal lineages,” Behar said Thursday.

His study involved analyzing mtDNA from about 11,000 samples representing 67 populations.