study arguing that "GPS is a provenancing tool suited to inferring the geographic region where a modern and recently unadmixed genome is most likely to arise, but is hardly suitable for admixed populations and for tracing ancestry up to 1000 years before present, as its authors have previously claimed.
Moreover, all methods of historical linguistics concur that Yiddish is a Germanic language, with no reliable evidence for Slavic, Iranian, or Turkic substrata." The authors concluded: "In our view, Das and co-authors have attempted to fit together a marginal and unsupported interpretation of the linguistic data with a genetic provenancing approach, GPS, that is at best only suited to inferring the most likely geographic location of modern and relatively unadmixed genomes, and tells nothing of population history and origin." In 2016 Elhaik having reviewed the literature searching for a ‘Jüdische Typus’ argued that there is no genomic hallmark for Jewishness.
The studies show that the Bene Israel and Black Cochin Jews of India, and the Beta Israel of Ethiopia, while more closely resembling the local populations of their native countries, have some ancient Jewish descent. They suggested that most Jewish communities in the Diaspora remained relatively isolated and endogamous compared to non-Jewish neighbor populations.
According to Behar and colleagues (2010), this is "consistent with the historical formulation theories the Jewish people as descending from ancient Hebrew and Israelites of the Levant" and "the dispersion of the people of ancient Israel throughout the Old World" Jews living in the North African, Italian, and Iberian regions show variable frequencies of admixture with the historical non-Jewish host population along the maternal lines.
While he allows that in the future it is possible that a ‘Jewish’ marker may turn up, so far, in his view, Jewishness turns out to be socially defined (a socionome), determined by non-genetic factors.
Scholars such as Harry Ostrer and Raphael Falk believe this may indicate that many Jewish males found new mates from European and other communities in the places where they migrated in the diaspora after fleeing ancient Israel.
With the exception of Ethiopian Jews and Indian Jews, it has been argued that all of the various Jewish populations have components of mitochondrial genomes that were of Middle Eastern origin. published work suggesting that an overwhelming majority of Ashkenazi Jewish maternal ancestry, estimated at "80 percent of Ashkenazi maternal ancestry comes from women indigenous to Europe, and [only] 8 percent from the Near East, with the rest uncertain", suggesting that Jewish males migrated to Europe and took new wives from the local population, and converted them to Judaism.
Another study by Eva Fernandez and her colleagues argues that the K lineages (claimed to be European in origin by Richards et al) in Ashkenazi Jews might have an ancient Near Eastern source.