Founding Mothers of Ashkenazi Jews May Be Converts, Study Finds
Elizabeth Lopatto, Bloomberg, Oct 8 2013
About 80% of Ashkenazi maternal ancestry comes from Europe, not the Near East, according to a study that suggests a mass conversion of women to Judaism may have occurred in Europe more than 2,000 years ago (actually it was between 740 and 900 CE – RB). The findings come from studying mitochondrial DNA, which passes from mother to offspring, in about 3,500 people, the authors wrote in a paper in the journal Nature Communications. About 80% of the maternal linages of Ashkenazi Jews came from Europe, the scientists found. The Ashkenazi are the most common Jewish ethnic division. Previous efforts to trace origins of Ashkenazi Jews have been spotty and controversial, the authors wrote. The latest research used a larger database than in previous attempts, allowing them to unravel the entire mitochondrial genomes. The authors, led by Gil Atzmon of the Albert Einstein College of Medicine in New York, wrote:

A detailed genealogical history for every maternal lineage in the Ashkenazim is now within reach. In fact, it should soon be possible to reconstruct the outlines of the entire dispersal history of each community.

The four major female founders of the Ashkenazi show roots in Europe 10,000 to 20,000 years ago. So do most of the minor founders, the study found. Only 8% of the mitochondrial DNA shows signs of being from the Near East. There had been some evidence of mass conversions, especially of women, to Judaism throughout the Mediterranean in the past, the authors wrote in the study. That resulted in about 6 million citizens, or a tenth of the Roman population, who were Jewish.