First, the fact that Jews are most closely related to Northern Italians does not imply that this was due to conversion in the ancient world. He points out that “the relatively greater similarity of Jews to southern rather than central/eastern Europeans may also to some extent reflect the greater Neolithic ancestry in the southern European groups that is shared by various Jewish groups as one component of their ancestry.”
In other words, the similarity may be due to simple geographic closeness. The similarity may be due to similarities that long pre-date the Jewish Diaspora in the Greco-Roman world of antiquity. This then suggests that my doubts about large-scale conversions to Judaism in the ancient world may be well-founded after all.
Further, the fact that there is very little similarity between Ashkenazi Jews and Eastern and Central Europeans indicates that Ashkenazi Jews remained separate from these populations for hundreds of years.
Sallis also points out that there are technical problems with the PCA analysis — the analysis with the pretty picture showing genetic distances. Such pictures are beguiling and doubtless represent the take-home message for most people. The picture suggests that Ashkenazi Jews (ASH) are more closely related to Northern Italians than to Iranian or Iraqi Jews. But this is not actually the case. In fact, Gil Atzmon explicitly denies it here.
But the IBD (Identical By Descent) analysis provides a very clear picture indicating very close relatedness among Jewish groups. IBD analysis compares gene sequences that are similar or completely identical because they descend from a common ancestor.
As Sallis notes, “this is a strong demonstration of the common origins and very close genetic connections among these groups.” Indeed, twelve of the thirteen comparisons with the highest degree of sharing are between Jewish groups. (The red bars in Part A of the figure represent comparisons of Jews with other Jewish groups.) This analysis shows that Ashkenazi Jews (ASH in the figure) are substantially more closely related to all other Jewish groups than to any non-Jewish group, including the Northern Italians.
Finally, Sallis makes the important point that
when it comes to Jewish populations and the relatively small genetic distance separating Jews from both Europeans and Middle Easterners, “academics” (particularly Jewish scientists) and the media (as well as Jewish ethnic organizations) have no problem in stressing the genetic uniqueness of Jews and that this uniqueness stamps them as a separate and distinct biological/ethnic entity.However, when it comes to the objectively larger genetic gulf that separates Europeans from, say, Africans or Asians, why, that’s only an “illusion,” there is “no biological basis for race,” “we are all the same,” and “there is more genetic variation within groups than between them.”The contrast in attitude could not be greater.
Indeed, the Forward has an editorial based on the Atzmon et al. article titled “We are one genetically.” They clearly see the data as a wake-up call for Jews to preserve their genetic heritage:
In an age when exclusivity is frowned upon and multiculturalism prized, some Jews may celebrate if the genetic distinctions fade away and are replaced by a more pluralistic definition of who we are — or at least, who our genes say we are. But breaking down the cultural and religious isolation that has characterized Jewish life since ancient times also contains risks. Science tells us that we have, indeed, been one people. Will we remain so?
Well, the only people whose exclusivity is frowned on are White Europeans. But the sad reality is that Jews will continue to attempt to have their cake and eat it too on the issue of concern for genetic continuity as they have on all the other issues related to multiculturalism and Israel: Support for massive non-White immigration and opposition to White identity and interests in America and other Western societies while supporting an ethnonationalist, apartheid state in Israel and taking steps to ensure Jewish genetic continuity in the Diaspora.
Again, it’s worth remembering that a major motivation of the Jabotinsky faction of racial Zionists that now rules Israel was to prevent genetic assimilation that they saw going on the Diaspora. (See Ch. 5 of Separation and Its Discontents, p. 152ff.) They succeeded in their aims.