Book Review

Jacob's Legacy: A Genetic View of Jewish History

N Engl J Med 2008; 359:980-981August 28, 2008

Article

Jacob's Legacy: A Genetic View of Jewish History
By David B. Goldstein. 148 pp. New Haven, CT, Yale University Press, 2008. $26. ISBN: 978-0-300-12583-2

In 1875, the newly graduated Cambridge polymath Joseph Jacobs wrote a review of George Eliot's last completed novel, Daniel Deronda, the story of a young English gentleman who discovers his Jewish identity. The experience was transformative for Jacobs; not only did he launch his literary career through his friendship with Eliot (whose given name was Mary Anne Evans) and her illustrious circle, but in the process he also discovered his own Jewish identity. Through his subsequent work in physical anthropology, he became a defender of the concept of a Jewish race. As he wrote in the Jewish Encyclopedia in 1901, “the remarkable unity of resemblance among Jews, even in different climes, seems to imply a common descent.” Drawing on the newly rediscovered science of genetics, he decided that the shared physical characteristics of Jews must be genetically determined.

In the 1990s, the application of genetic methods to the discovery of Jewish origins (and the occurrence of the first Gulf War) had a similar transformative experience for David Goldstein, the author of Jacob's Legacy. While a graduate student in human genetics at Stanford University, Goldstein was mentored by the illustrious population geneticists Marcus Feldman and Luca Cavalli-Sforza. Armed with his expertise of microsatellite marker analysis as a way of timing human population divergence, Goldstein set off for England for a professorship at Oxford University. On the way, he forged a friendship with Neil Bradman, a successful English businessman with a passion for science, who became his graduate student and supporter. With the aid of molecular geneticist Mark Thomas, they performed a series of studies that linked the genetics of contemporary Jews with historical and biblical records.

Their far-reaching studies are the subject of Jacob's Legacy. They demonstrated that most Jewish men who claim descent from the biblical priests share a set of genetic markers on their Y chromosomes that arose approximately 3000 years ago. This set of Y chromosomal markers was called the Cohen Modal Haplotype (CMH), and it may have been carried by Aaron, the brother of the patriarch Moses and the first of the Jewish priests. Working with Lost Tribes anthropologist Tudor Parfitt, Goldstein, Bradman, and Thomas went on to show that the CMH was found among the Lemba tribe of southern Africa and at a particularly high frequency in the Buba, one of the many clans within the Lemba tribe. The Lemba were known as President Kruger's Jews because of their claim of Jewish heritage and their observance of certain religious practices common among Jews and Muslims, including monotheism, dietary laws, and circumcision. The prevalence of the CMH among Lemba men affirmed their claim of Semitic, and possibly Jewish, heritage.

The discoveries of Goldstein and his collaborators about the origins of the Levites, the priestly helpers, were equally startling. They found that the CMH was prevalent among Levite men of North African and Middle Eastern Jewish origin, but not among those of Eastern European (Ashkenazi) Jewish origin. Rather, the Ashkenazi Jewish Levites had a Y chromosomal type that originated in central Asia. This observation provided circumstantial evidence for a myth popularized by Arthur Koestler in his book The Thirteenth Tribe (New York: Random House, 1976), that Ashkenazi Jews were descended from the Khazars of central Asia. The Goldstein group also extended its studies to Jewish maternal origins through the analysis of mitochondrial DNA types among the Diaspora. The researchers found less diversity in the Jewish mitochondrial types as compared with those of the local non-Jewish populations, thus demonstrating that many of the groups in the Diaspora were descended from a discrete number of founding mothers, distinctive for each group, and not necessarily the biblical matriarchs.

Goldstein's observations have been refined and revised by others as more markers and more populations have been studied — the CMH has been divided into two halves, each of which arose at an earlier time than that of Aaron the Priest. In response, Goldstein acknowledges that microsatellite markers are suboptimal for studying human history, as their rates of mutation are high and unknown. The more extensive studies of Doron Behar and his collaborators of maternal origins have substantiated Goldstein's scenario of Jewish men, perhaps traders along the Silk Road or the Arabian Peninsula, establishing local communities and marrying local women.

This genetic view of Jewish history may have seemed fanciful to Joseph Jacobs and to George Eliot's other readers. In our era, it has captured the public's attention. Through the print media, public radio stories, and the television series NOVA, the public has become aware of the potential for genetic analysis to test and validate hypotheses about human history. Today, there are many amateur Goldsteins who study their place in human history through analysis of their own mitochondrial and Y chromosomal types. As Goldstein has written, “Our genetic heritage is ours to treasure, to explore and to marvel at.”

Harry Ostrer, M.D.
New York University School of Medicine, New York, NY 10016
harry.ostrer@nyumc.org