Various studies have arrived at diverging conclusions regarding both the degree and the sources of the non-Levantine admixture in Ashkenazim, particularly in respect to the extent of the non-Levantine genetic origin observed in Ashkenazi maternal lineages, which is in contrast to the predominant Levantine genetic origin observed in Ashkenazi paternal lineages. All studies nevertheless agree that genetic overlap with the Fertile Crescent exists in both lineages, albeit at differing rates. Collectively, Ashkenazi Jews are less genetically diverse than other Jewish ethnic divisions.

All studies agree that genetic overlap with what location exists in both lineages?