DNA and the Origins of the Jewish Ethnic Groups

A long-standing debate concerns the ethnic origins of the Ashkenazi (Eastern European) Jews. Are they of predominately the same ancestry as the Sephardic (Southern) and Oriental Jews? Or are they, to a large extent, descended from a different origin, perhaps the Khazar (Turkic) converts to Judaism in the 8th and 9th Century? A parallel debate concerns the genetic origins of the Lemba, a Bantu tribe in southern Africa who claim Jewish paternal ancestry. Hammer et al. (2000) published an exploratory paper with this conclusion "The results support the hypothesis that the paternal gene pools of Jewish communities from Europe, North Africa, and the Middle East descended from a common Middle Eastern ancestral population, and suggest that most Jewish communities have remained relatively isolated from neighboring non-Jewish communities during and after the Diaspora."

Table 1 excerpts haplotype percentages from Hammer. Ethnic groups commencing "J" are recognized to have Jewish ethnicity. Those commencing "G" to be non-Jewish. "?" indicates the two groups that are the focus of the study. Hammer et al. investigate with various descriptive statistics. What insights does a measurement approach provide?

Table 1: Y-Chromosome haplotype frequency % (from Hammer et al., 2000, Table 1)
4S	1R	Med	1Ha	1U	1C	1L	1D	Other	Ethnic Group
16 20 13 8 17 45 24 6 19 10 29 19 5 15 50 6 6	0 2 3 4 0 0 12 6 5 3 13 0 5 16 1 0 12	45 42 28 44 43 10 31 26 51 57 46 38 33 11 26 1 26	5 18 6 6 0 0 2 0 3 3 0 19 5 6 0 0 9	7 7 16 18 7 5 3 32 7 6 4 19 24 2 4 1 12	0 4 31 8 10 0 4 0 1 1 0 5 5 1 1 0 3	20 2 3 8 17 0 10 0 8 9 0 0 0 37 4 0 20	5 4 0 4 3 0 9 0 0 9 4 0 19 11 1 0 5	2 0 0 0 3 40 3 29 5 0 4 0 5 1 12 93 6	J-Roman J-North African J-Near Eastern J-Kurdish J-Yemenite J-Ethiopian ?-Ashkenazi ?-Lemba G-Palestinians G-Syrians G-Lebanese G-Druze G-Saudi Arabians G-Europeans G-North Africans G-Sub-Saharan G-Turks

The first step is to orient the 9 haplotype variables with the construct of interest, Jewish ethnicity. At this point, the Ashkenazi and Lemba are omitted from the analysis, so as not skew their own placement within the construct. The "J" groups are anchored at 2 logits. The "G" groups at 0 logits. The difference between the two anchor values is chosen to be big enough to make a clear distinction in the output. An analysis in which each haplotype "item" is allowed to define its own rating scale ("partial credit") is then performed. Since the meaning of percentage gaps is not clear, the unobserved percentages are treated as structural zeros and are dropped out of the rating scales. This analysis indicates that haplotypes 1D, 1R and "Other" are negatively oriented (large negative correlations), so that larger percentages indicate less Jewish Ethnicity. "Med", 1L and 1Ha have almost zero correlations.

6 + | G-Druze 5 + | 4 + | 3 + | J-Near Eastern 2 + J-Yemenite | J-North African 1 + | J-Kurdish 0 + G-North Africans J-Ethiopian J-Roman | G-Palestinians -1 + | G-Syrians -2 + G-Lebanese G-Saudi Arabians | -3 + G-Turks | G-Europeans G-Sub-Saharan -4 +

Figure 1. Ethnicity measures without Ashkenazi, Lemba

The second step is to reverse-code the negatively-oriented percentages and drop the haplotypes with very low correlations. The analysis is rerun without anchoring and still without the focus ethnicities. Figure 1 plots the resulting ethnicity measures. Logits have been scaled by 10, and the origin located at a meaningful point. It is seen that there is a neat stratification of "J" and "G" ethnicities, except for the Druze. The Druze number about 1 million and are located in southern Syria and Lebanon, and northern Israel. They originated from an Islamic reform movement in Egypt in the 11th Century. Exactly what this implies for their ethnicity is not clear. Perhaps, if this study had included "Egyptians" we would be better informed. In the present instance, however, we do not want to evaluate the "Druze-ness" of the focus ethnicities, and so the Druze are dropped from the study. Repeating the first step without the Druze, indicates that 1Ha now has a positive correlation and so is kept in the analysis. The results already shown in Figure 1, but now without the Druze, emerge again.

The focus ethnicities are now introduced into the data, and measures constructed. Figure 2 depicts the results. The basic "J"-"G" contrast remains. The "Ashkenazi" are positioned between the "J" and the Turks, suggesting the possibility that they have both Jewish and Turkic descent. The Lemba are positioned between the "J" and the Sub-Saharan, also suggesting they may have mixed descent.

3 + J-Near Eastern | J-North African | | | 2 + | | J-Yemenite | J-Kurdish | 1 + | | G-North Africans J-Roman | G-Palestinians J-Ethiopian | 0 + | | G-Syrians | | ?-Ashkenazi -1 + G-Saudi Arabians | G-Lebanese | G-Turks ?-Lemba | | -2 + G-Europeans | | | | -3 + G-Sub-Saharan

Figure 2. "Jewishness" of Ethnic Groups

John M. Linacre

M. F. Hammer, A. J. Redd, et al. (2000) Jewish and Middle Eastern non-Jewish populations share a common pool of Y-chromosome biallelic haplotypes . Proc. Natl. Acad. Sci. USA, Vol. 97, Issue 12, 6769-6774, June 6, 2000

DNA and the origins of the Jewish ethnic groups. Hammer MF, Linacre JM. … Rasch Measurement Transactions, 2002, 16:1 p.862-3

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