Some 3.5 million of today's Ashkenazi Jews -- about 40 percent of the total Ashkenazi population -- are descended from just 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.
He did the work with Karl Skorecki of the Technion-Israel Institute of Technology and others.
Each woman left a genetic signature that shows up in their descendants today, he and colleagues say in a report published online by the American Journal of Human Genetics. Together, their four signatures appear in about 40 percent of Ashkenazi Jews, while being virtually absent in non-Jews and found only rarely in Jews of non-Ashkenazi origin, the researchers said.
They said the total Ashkenazi population is estimated at around 8 million people. The estimated world Jewish population is about 13 million.