The new study, by Dr. David Goldstein, Dr. Mark Thomas and Dr. Neil Bradman of University College in London and other colleagues, appears in The American Journal of Human Genetics this month. Dr. Goldstein said it was up to historians to interpret the genetic evidence. His own speculation, he said, is that most Jewish communities were formed by unions between Jewish men and local women, though he notes that the women's origins cannot be genetically determined.What We Can Learn From the Jewish Genome - Newsweek:
...The Druze, Bedouins, and Palestinians were closest to the Iranian, Iraqi, and Syrian Jews. That is evidence of “a shared genetic history of related Middle Eastern and non-Semitic Mediterranean ancestors who chose different religious and tribal affiliations.”
During that period Jews proselytized with an effectiveness that would put today’s Mormons to shame: at the height of the Roman Empire, as the Roman historian Josephus chronicled, mass conversions produced 6 million practicing Jews, or 10 percent of the population of the Roman Empire. The conversions brought in DNA that had not been part of the original gene pool in the land of Abraham.