THE HISTORY OF THE JEWISH RACE

Although belief is at the core of Judaism, as an ethnic religion, Jewish life is deeply rooted in tradition. In modern times, the notion of a "Jewish race" has emerged, invoking widespread controversy concerning the nature of the Jewish identity. In order to resolve this issue, many scholars have looked to science for an objective viewpoint.

STUDIES:

Physical Anthropology

At the beginning of the 20th century, the study of race was still primarily confined to physical anthropology. Early studies conducted on the physical anthropology of Jews lacked scientific rigour and little substantial findings could be made. Many of these studies focused on cephalic index, which has since been rejected as a valid racial marker.

In 1957, Leon Sachs and Miriam Bat-Miriam examined the fingerprints of a sample of 4,000 Jews hailing from Poland, Germany, Iraq, Egypt, Morrocco, Yemen, Bulgaria and Turkey. The study found "striking similarities" between the Jewish groups, which also resembled other eastern Mediterranean groups.

Eugene Kobyliansky has studied the physical anthropology of Jews in a number of studies. In 1985 Kobyliansky did a comparative study of the dermatoglyphics of four Jewish groups and five non-Jewish groups. Using cluster analysis, the study placed the Ashkenazi, North African and Oriental Jewish groups together, along with two non-Jewish West Asian groups. Distant from the cluster were the Eastern European non-Jews, the Yemenite Jews, and the Mongoloid and Negroid samples.

Again in 1985, Kobyliansky compared data for several morphological measurements among Jewish and non-Jewish groups, once again finding the Jewish groups to cluster with each other. Comparing Soviet Jews with 24 other ethnoterritorial groups in the USSR, the study also found Jews to be the most distinct of all the groups, with the exception of the Korean group.

A comparison of the dental morphology of four contemporary and one skeletal Jewish sample, as well as seven non-Jewish samples, was performed by JA Sofaer. The study applied 19 dental morphological variables, selected to show maximum variation between groups and maximum independence from each other. Applying both metric and non-metric multivariate analyses, Jewish groups were found to show close affinity to one another, with the exception of the Habbanite group.

Classical Genetic Markers

The explosion of genetics in recent decades has created a more rigorous, systematic approach to the study of race. With large sets of genetic data available, many comparisons have been made of the gene frequencies of different populations.

The 1979 book, "Genetic Diseases Among Ashkenazi Jews" marks the beginning of a new stage in the study of Jewish origins. With contributions from authors Bonne-Tamir, Szeinberg and Cavalli-Sforza, the book shed light on the distribution of classical genetic markers in the Ashkenazi Jewish population as compared to other Jewish and gentile communities. The studies found close affinities between Ashkenazi and non-Ashkenazi Jewish groups, showing clear distinctions from non-Jewish European groups. This was continued by Karlin et al in one of the largest surveys of Jewish gene frequencies to date, finding "Ashkenazi, Sephardi and Iraqi Jewish populations to be consistently close in genetic constitution and distant from all the other populations, namely the Yemenite and Cochin Jews, the Arabs, and the non-Jewish German and Russian populations."

Bonne-Tamir would later compare a number of Jewish groups and several South-West Asian groups based on similar data. Producing two dendrograms, Irani, Iraqi, Georgian and Ashkenazi Jewish samples showed marked similarity to one another, clustering with each other and apart from Muslim samples.

These results have been corroborated by several additional studies, although as noted in "Genetic Diseases Among Ashkenazi Jews", some genetic systems, such as the ABO blood groups, presented conflicting results. Cavalli-Sforza, Bonne-Tamir and other scientists debated about the "heterogeneity of admixture rates" for the different genetic systems, and could only assume that the overall admixture rate for Ashkenazi Jews was small.

Arno Motulsky addressed this issue in his 1980 study, "Ashkenazi Jewish gene pools: admixture, drift and selection", creating an estimate for the European admixture rate among Ashkenazi Jews based on a maximum likelihood method. Combining 18 markers, the study found an admixture rate of 12.5%, with a 95% confidence interval of 3-18% and a 99% confidence interval of 2-20%. An important factor in the overall low admixture rate is that the markers pointing to higher admixture rates generally showed less statistical significance than other markers.

Mendelian Diseases

Because most classical genetic marker variants are present in all populations, they are not always useful in tracing ancestry. Markers representing recent mutations, such as those associated with rare genetic disorders, are valuable in this respect. With haplotype analysis, these mutations can be dated and traced to a number of individual founders, providing a cladistic approach to the study of phylogeny.

Jews are unique for being prone to a large number of rare genetic diseases. Many of these diseases are deemed "Jewish" diseases as they are found almost exclusively among Jews, and Ashkenazi Jews in particular. The majority of these diseases are autosomal recessive disorders, which has led to some suggestions that they might have arisen through inbreeding. While inbreeding increases the number of affected homozygotes for this type of disorder, it decreases the number of heterozygotes capable of passing the trait to later generations. Inbreeding therefore is not a legitimate explanation for the elevated frequency of certain disease genes among Ashkenazi Jews. It is most likely that this phenomenon is simply the result of chance mutations, combined with a rapid growth rate in the once small Jewish community of Europe.

Roman Jews have inhabited Rome continuously since the dawn of the Diaspora, and do not identify as Askhenazi or Sephardic. Many disorders once thought to occur solely among Ashkenazi Jews have recently been found among Roman Jews as well. The alleles conditioning these disorders show the same haplotypes, indicating a common origin. Some mutations not found in Roman Jews probably have more recent founders in the Ashkenazi population, although others may have originated in Jewish communities other than that of Rome.

Genetic diseases such as Torsion Dystonia and Bloom Syndrome have been found to have relatively recent origins in the Jewish community, exhibiting founder effects visible in their geographic distribution. The distribution of these diseases have been correlated with cultural and linguistic patterns, such as the traditional division between Litvaks (Lithuanian Jews) and Galitzianers (Galician Jews).

Interesting observations have also been made with respect to typical "Jewish" diseases in groups that are not Jewish. The 185delAG mutation associated with familial breast cancer is found not only among Ashkenazi, Sephardic and Iraqi Jews, but also at a low frequency among Spanish gentiles, and in particular gypsies and Spanish-Americans. The extremely rare Bloom Syndrome has even been encountered in German gentile populations. In addition to assimilation in modern societies such as Spain and Germany, conversion to Christianity and Islam was so widespread in the first millenium that it greatly reduced the world Jewish population. This is seen in a number of rare genetic diseases found in both Ashkenazi Jews and non-Jewish Mediterranean populations, such as essential pentosuria, non-syndromic deafness and certain cystic fibrosis alleles.

Molecular Genetics

DNA fingerprinting has created a more direct approach to the study of genetic clades. In addition, unlike mutations associated with genetic diseases, polymorphisms found through DNA fingerprinting are generally non-genetic and not likely to be influenced by natural selection.

An analysis of nine short tandem repeat (STR) polymorphisms in Israeli Jews and Arabs found significant differences between the two groups in four of the nine markers. In spite of the subpopulation structure among the two groups, the study supported the use of Jews and Arabs as homogenic groups. Neither group deviated significantly from Hardy-Weinberg equillibrium, although the Arab group seemed to deviate more than the Jewish group. The Arab group showed a lower matching probability than the Jewish group, indicating greater diversity.

A similar study was performed in 1986, focusing on restriction fragment length polymorphisms (RFLPs) drawn from the mitochondrial DNA of Israeli Jews and Arabs. This study found substantial differences between the Jewish and Arab samples, only 3 out of 18 mtDNA types being common to both groups. The Arab group again showed more diversity than the Jewish group, and was found to exhibit typical African characteristics. This is consistent with a number of other studies on mitochondrial DNA also finding close affinities between Jewish groups, as well as African characteristics among Israeli Arabs.

A very important aspect of mitochondrial DNA is that unlike nuclear DNA, it is inherited directly down the maternal line, receiving no paternal contribution during meiosis.