Surprise: Ashkenazi Jews Are Genetically European // livescience.com – Little is known about the history of Ashkenazi Jews before they were expelled from the Mediterranean and settled in what is now Poland around the 12th century. On average, all Ashkenazi Jews are genetically as closely related to each other as fourth or fifth cousins, said Dr. Harry Ostrer, a pathology, pediatrics and genetics professor at the Albert Einstein College of Medicine in New York and the author of “Legacy: A Genetic History of the Jewish People” (Oxford University Press, 2012).
But depending on whether the lineage gets traced through maternal or paternal DNA or through the rest of the genome, researchers got very different answers for whether Ashkenazi originally came from Europe or the Near East.
Past research found that 50 percent to 80 percent of DNA from the Ashkenazi Y chromosome, which is used to trace the male lineage, originated in the Near East, Richards said. That supported a story wherein Jews came from Israel and largely eschewed intermarriage when they settled in Europe. [The Holy Land: 7 Amazing Archaeological Finds]
But historical documents tell a slightly different tale. Based on accounts such as those of Jewish historian Flavius Josephus, by the time of the destruction of the Second Temple in A.D. 70, as many as 6 million Jews were living in the Roman Empire, but outside Israel, mainly in Italy and Southern Europe. In contrast, only about 500,000 lived in Judea, said Ostrer, who was not involved in the new study.