The genetic research clearly shows that, even though there is no "Jewish DNA," there is definite biological-genetic evidence that the Jews are one people. The researchers found that despite their long-term residence in different countries and isolation from one another, most Jewish populations were not significantly different from one another at the genetic level. The researchers studied seven Jewish populations: Yemenite, Ashkenazic, Near Eastern, North African, Asia Minor, the Balkans and Ethiopian. The first six showed a strong affinity, with the Ashkenazic and Yemenite populations coming out the closest. Palestinian, Syrian and other non-Jewish Middle Eastern populations were also very close to the Jewish populations. Other research shows that the Jews in different countries are much closer to Jews in other countries than to their non-Jewish neighbors. If modern-day Jews are descendants of converts, as Sand claims, then there would have been no similarity between the different Jewish communities. And the Jewish populations would have been similar to their non-Jewish neighbors. In fact, the Ethiopian Jewish community is different from the other Jewish communities because it originated from descendants of local converts. The Ashkenazi Jews were not found to be similar to present-day Turkish speakers. This opposes the suggestion that Ashkenazi Jews descended from the Khazars. Dr. Neil Risch, a researcher at the Department of Genetics at Stanford University, said: "If you made a genetic map of Europe and the Middle East and you put Ashkenazi Jews on it, they would not end up in Turkey or in the middle of Europe, but in the Mediterranean." The results of the research support the notion that modern Jews descended from a common Middle Eastern ancestral population. Contrary to Sand's assertion, both history and science support the existence of the Jewish people.
from the article: DNA links prove Jews are a 'race,' says genetics expert