. Finally, it's worth noting that the Y-chromosome work by Ritte et al. (1993) suggests that the Jewish community most closely related to the Ashkenazim are the Jews of Yemen (in terms of patrilineal lineage)

The amount of mitochondrial diversity is comparable to what one would expect in a region the size of New Guinea, but not larger. This suggests that a number of maternal lineages were assimilated from neighboring regions prior to the diaspora.

this work shows that Jews are a single ethnic group, in the sense that the major Jewish communities are typically more closely related to each other than to their neighbors. This does not mean that they share no ancestry with their immediate neighbors, but rather that intermarriage with their neighbors has had only a modest impact on the genetic makeup of most Jewish communities. That may be because the rate of intermarriage has been very low, or because intermarriage normally resulted in a loss of affiliation with the Jewish community. There are some Jewish communities which are an exception to this, and are probably descended mostly from local converts, the most obvious example being the Jews of Ethiopia (see below). However, the results are consistent with bulk of Jewish community having its origins in the Eastern Mediterranean.