Ted Sallis: More Jewish Genetics: The "Weak Khazar Hypothesis"

Ted Sallis:  An important new paper (free online; see here) has come out on Jewish population genetics.  

The populations used in this study are described as: 

The Middle Eastern populations included in the study were Bedouin (46), Druze (42), Mozabite (29), and Palestinian (46). The European populations were Adygei (17), Basque (24), French (28), Italian (13), Orcadian (15), Russian (25), Sardinian (28), and Tuscan (8). Middle Eastern and European non-Jewish individuals were taken from the H952 subset of the HGDP-CEPH panel [24]. The Jewish samples included Ashkenazi Jews (20), Moroccan Jews (20), Tunisian Jews (20), and Turkish Jews (20). 

The major findings are described below, emphasis added: 

Abstract: Background: Genetic studies have often produced conflicting results on the question of whether distant Jewish populations in different geographic locations share greater genetic similarity to each other or instead, to nearby non-Jewish populations. We perform a genome-wide population-genetic study of Jewish populations, analyzing 678 autosomal microsatellite loci in 78 individuals from four Jewish groups together with similar data on 321 individuals from 12 non-Jewish Middle Eastern and European populations.

Results: We find that the Jewish populations show a high level of genetic similarity to each other, clustering together in several types of analysis of population structure. Further, [statistical analyses] place the Jewish populations as intermediate between the non-Jewish Middle Eastern and European populations. Conclusion: These results support the view that the Jewish populations largely share a common Middle Eastern ancestry and that over their history they have undergone varying degrees of admixture with non-Jewish populations of European descent. 

Neighbor-joining population trees obtained for the three distance matrices were generally quite similar (Figure 3). All three trees are divided into a European side and a Middle Eastern side, with the four Jewish populations located in the interior. 

This result … assigns the Jewish populations and the Palestinians to the same cluster (Figure 2), and by the relatively close placement of the Palestinians and the Jewish populations in MDS plots of individual distances (Figure 5). 

What about the Khazars? 

One frequently discussed conversion that likely occurred in the 8th century at the far eastern edge of Europe, north of the Caucasus and Black Sea regions, is that of the Khazarian kingdom [60, 62, 64]. The demographic effect of this conversion is debated, so that only a small minority of the Khazars may have adopted Judaism. While the ultimate fate of the Khazar population remains unknown, the theory has been advanced that a large fraction of the ancestry of eastern European Jews derives from the Khazars [60, 62-64]. This theory would predict ancestry for the eastern European Ashkenazi Jewish population to be distinct from that of the other Jewish populations in the study. Although we did not observe such a distinct ancestry, it is noteworthy that in some analyses (Figures 2 and 3), as was observed in the recent study of Need et al. [10], we did detect similarity of the Adygei, a north Caucasian group from the area once occupied by the Khazars, to the Jewish populations. 

This is consistent with what I’ve said in the past. The data are consistent with a “weak Khazar hypothesis” — that Ashkenazi Jews may have some fraction of Khazar ancestry but are more closely linked to other Middle Eastern groups. On the other hand, the “strong Khazar hypothesis” — that the Ashkenazim are merely “converted Khazars without any connection whatsoever to the Middle Eastern populations of the classical world (i.e., Hebrews)” — is highly unlikely.  Not only are the Ashkenazim genetically close to the Sephardim (who have traditionally been considered as likely Hebrew descendants), but this study yet again confirms previous findings of a significant fraction of historical Middle Eastern ancestry in the Ashkenazim. 

Therefore, the idea that the Ashkenazim are simply Khazars with no Middle Eastern ancestry is untenable.

However, equally untenable is the idea that the Ashkenazim are “just like Europeans” and are not distinct from the European genepool.  It is quite clear that Europeans are different from Middle Easterners, with various Jewish groups positioned intermediate to those two major Caucasian continental population groups.  Indeed, it may be reasonable to see Jews as a “mini-race” as they are distinct from both Europeans and Middle Easterners and are indeed more similar to each other than to these other groups.  This conclusion is supported by the work of Need et al. (Note 1), which demonstrated that 1/4 Jewish ancestry can be detected in individuals.  This ability to detect 1/4 Jewish ancestry, in a reasonably reliable manner, within the broader Caucasian family suggests a degree of racial differentiation of Jews sufficient for consideration as a separate (sub-) racial group.

In general, these findings support Jewish history and tradition, given the commonalities of the Ashkenazim and Sephardim, as well as the Middle Eastern connection.  One would think that persons of Jewish ancestry would be well pleased with these findings, which have a strong empirical basis.  Indeed, persons who falsely claim that the Ashkenazim are “Europeans” are as anti-Semitic as those who continue, in the face of all contradictory evidence, to peddle the “strong Khazar hypothesis.”

Note that discussions of the Ashkenazim as a group do not necessarily cover all individuals of this group.  Likely (and supported to some extent by this paper) individual Ashkenazim may be essentially genetically European, and others genetically Middle Eastern, even when most of their fellows are intermediate to those populations. Global similarity analyses, such as the quantitative measurement offered by 23andme (using over 500,000 autosomal SNP markers), may be useful to determine the genetic affinities of individual Ashkenazim (and Sephardim); particular individuals may be quite different from their ethnic genetic centroid.

That being said, this paper’s data are fairly clear that the Ashkenazi (and Sephardic) genepool, as a whole, is not European, and it is not Middle Eastern either.  It is a unique and distinct blending of these ancestries.  This analysis is in no way a commentary on the debates found elsewhere on the Internet about “are the Jews white?”  Different people draw the line of “whiteness” at different places within the Caucasian family of peoples.  The issue here is, instead, empirical determination of the place of Ashkenazi and Sephardic Jews in the genetic spectrum of human populations.  This paper is an important contribution to our understanding of this complex and fascinating topic. 

This paper also refutes some self-serving stupidity that a part-Jewish and highly confused commentator has been making, in that he incorrectly asserts that the major biological/genetic split of Caucasians is within Europe, with northern Europeans (who he bizarrely believes underwent racial differentiation in India [!] of all places) separate from the other Europeans, who he thinks are in the Middle Eastern population branch. Of course, autosomal analyses consistently show this is incorrect, and I’ve previously cited those papers in other forums.  From the present paper (emphasis added): 

Neighbor-joining population trees obtained for the three distance matrices were generally quite similar (Figure 3). All three trees are divided into a European side and a Middle Eastern side, with the four Jewish populations located in the interior. This division is supported by relatively strong bootstrap values… …the basic pattern visible in all three trees, in which the Middle Eastern and European populations cluster separately with the Jewish populations in the center. 

European populations included are examples of Basque, French, Italian, Orcadian, Russian, Sardinian, and Tuscan.  Basque, Italian, Sardinian, and Tuscan are southern European. Orcadian is northern European, the French can reasonably be seen as “central,” and Russians are eastern European.  Given that European genetics is clinal as well as clustered, the arrangement of the populations in the “trees” is what one would expect. 

Note:

1. The Need et al.  paper also clearly shows a variety of European populations (similar to those analyzed in the paper discussed here) clustering separately from Middle Easterners, with Jews in an intermediate position.  Thus, different research groups, using different marker sets, are coming to the same conclusion – a conclusion supported by other peer-reviewed papers as well.