BOOKS JUNE 25, 2008
Jacob's Legacy: A Genetic View of Jewish History
By David B. Goldstein
(Yale University Press, 148 pp., $26)
Early in my career as a specialist in blood diseases and cancer, I cared for a middle-aged man who had melanoma. The cancer had spread from an early lesion on his trunk to his lungs, liver, and bones. He was a successful businessman, intelligent and outgoing, with a sharp sense of humor. Through the course of his treatment, we developed a warm relationship, and he made it clear that, when the end came, he wanted to be at home. As that time approached, he asked if I might see him one last time.
And so, on a spring evening, I drove west to Sherborn, Massachusetts. His home was of a stately Georgian design, and there were stables with horses grazing in a nearby meadow. Along the staircase to his third-floor bedroom was a series of portraits of his forebears. The picture at the base of the stairs was of his father, a stern-looking gentleman who had the features of Calvin Coolidge. The portraits were hung in chronological order, and at the apex of the staircase was a painting, more than two hundred years old, of the founding member of the family. I learned later that he was among the first settlers of the Massachusetts Bay Colony.
I found him weak but lucid. He told me that he felt some comfort in knowing that his children would soon hang his portrait in the ancestral home. As I read David B. Goldstein's important and illuminating book--written with keen intelligence and deep love of its subject, without sacrificing scientific accuracy for the sake of tribal nostalgia--my memory of my visit to my patient and his ancestors unexpectedly returned. I thought again about him, what kind of person he was and what he had accomplished, and how much of his character and behavior could have been a legacy of his long lineage. And perhaps I thought of him because, like most Jews I know, I have no such portrait gallery of my forebears. My paternal grandmother came from Vilna, worked in a sweatshop on Rivington Street, and married my grandfather, who had also fled the czar, first to Holland and then to New York, where he sold fruit in the streets. The known roots of the Groopmans reach only to the nineteenth century. My mother's family was from the Carpathian Mountains of Hungary, close relatives of the Hasidic rebbe of Satu Mare, or Satmar; but despite this prestigious status at least in certain Jewish circles, the family lost much of its historical memory during the Holocaust.
Our ancestors had a fixed sense of identity as Jews. But we, their progeny, live in a modern world that is markedly less tribal. Culture is now more porous, as races and ethnic groups mix and marry in an open society. For many Americans, traditions have been diluted, and heritage has become remote. Not least for this reason, there is a growing thirst among many ethnic and racial groups to recapture the past. This thirst certainly underlies the current popularity of genealogical research. And the groups that seem most intent on finding links through time are those who were persecuted and driven into diaspora.
Despite some success in searching census records, baptismal books, and marriage documents, there is only so far that these displaced groups can go. Jews in particular face a daunting task, since few records from before the nineteenth century have been preserved. It was only then that the Austro- Hungarian Empire began to register them as members of society, part of a census that assisted in tax collection. Jewish Ashkenazi surnames familiar to us, such as Schneider or Rosenberg, were given by Christian bureaucrats to replace the traditional Hebrew patronymics. Sometimes the surnames were those of towns or villages where the Jews resided; at other times they were drawn from their professions, or simply a Germanic phrase. But once these names were fixed, bloodlines became more difficult to trace. The Sephardim, of course, were expelled from Spain and Portugal in the late fifteenth century, and as they migrated to Asia Minor and North Africa, the lineage of their original Spanish and Portuguese forebears was also largely lost.
So it is not surprising that, like African Americans, American Jews would turn to genetics as a way to reclaim their history. This attempt to reach into the past by using modern science, as Goldstein clearly and compellingly shows, is not as simple as many in the media have made it out to be. Mapping genes and then extrapolating to modern groups is nothing more precise than an exercise in probability. We can come only to partial conclusions, never to full certainty, about what the prevalence of certain genetic traits and markers says about our imagined ancestors.
Goldstein, a professor of molecular genetics at Duke University, wisely affirms from the outset that tracing historical movements and peoples using chromosomal analysis should not be overemphasized:
Genetic history is both more and less significant than it is depicted in popular accounts. It is less significant because the historical insights that can be achieved with genetics are always very specific and often fairly modest. Caught up as it is in the excitement of modern science, genetic history's power and importance are often overstated, whereas the real grandeur and detail of human history can only be seen in the context of our archeological and written legacies and, of course, our memories. But at times genetic history stretches the boundaries of its scientific formalism and hints at answers to bigger questions: What makes a people a people? What binds them together through time? What alienates them from some and aligns them to others?
To answer these intriguing questions, Goldstein begins with a succinct and easily understood description of the principles of genetics, particularly as they apply to human populations. He avoids technical jargon whenever possible, and defines the science in language that even a neophyte reader can readily grasp. His narrative then moves to the role of the male Y chromosome in identifying the cohanim, or the priestly caste in Judaism that was established in the Pentateuch as an office of succession from Aaron and his sons. Neil Bradman, a colorful character who was once a brilliant businessman and then switched careers to study genes and development, was the scientist who enticed Goldstein to pursue genetic history. Bradman and Dr. Karl Skorecki, a kidney specialist at the Rappaport Faculty of Medicine at the Technion Institute in Haifa, had investigated the validity of the oral tradition of patrilineal inheritance of the cohanim. They looked at the degree of variability of genes on the Y chromosome of Jews who did or did not claim such priestly origins. "Neil's insight was to realize that if the status of priesthood really was inherited from father to son there should be a record of it in the genomes of people today who consider themselves priests," Goldstein writes.
We are then treated to the kind of entertaining and enlightening story that can make science both appreciated and applauded by those outside the discipline.
Neil sent his son to the beach in Tel Aviv to collect DNA samples.... The team looked at one of the workhorses of Y chromosome genetics--an insertion of a chunk of DNA called an Alu repeat. They also looked at a microsatellite marker, a highly variable stretch of DNA sequence.... They compared the forms of these markers between priests and nonpriests in both Sephardi and Ashkenazi communities. The team hit a home run their first time at bat. They found a striking difference in the Y chromosomes of priests and nonpriests, a difference that was consistent in both the Ashkenazi and the Sephardi communities.
Following this initial success, which resulted in a publication in the prestigious journal Nature, Goldstein was recruited to the team.
I had earned the moniker Mr. Microsatellite and was an imminent transplant to Britain, nervously starting my first job at beguiling and frustrating Oxford University. In this e-mail, Neil introduced himself to me, told me what he was doing, and extended a cordial invitation to Shabbat dinner at its home. He signed himself 'Neil Bradman (of the Jews).' I had no way of knowing it then, but Neil Bradman of the Jews was to become one of my closest research partners over the next five years.
At the time, I thought either this guy, like me, had serious cut-and-paste issues in his e-mails or, more likely, he was barking mad.
Goldstein next reviews the salient tradition from the Bible on the origins of the cohanim as descendants of Aaron. The Aaronite family known as the Zadokites became hereditary high priests based on prophetic and historical texts. (Zadok is said to have been a tenth-generation descendent of Aaron who functioned as priest to Kings David and Solomon.) In the summer of 586 B.C.E., the Babylonians destroyed the First Temple. As described in Kings II, the chief priest Seraiah as well as his second in command and several other priestly "keepers of the threshold" were executed. Many of the surviving priests, as described in Ezra, were taken to Babylon during the fifty-year exile. In 538 B.C.E., the Persian King Cyrus, who had conquered the Babylonians, repatriated those who wished to return to their homeland. Drawing on Ezra as well as historical sources, Goldstein points out that some 50,000 Babylonian Jews returned to Jerusalem and re-established priestly sacrifices. Twenty years later, the Second Temple would be completed.
The sacerdotal history is recounted by Goldstein through the Seleucid King Antiochus, who was a threat to the purity of the bloodline of the cohanim. Antiochus IV is said to have sold the position of high priest to Jason sometime around 175 B.C.E., along with the right to transform Jerusalem into a Greek polis. Goldstein mentions that another priest, Menelaus, also tried to buy the office of high priest and to supplant Jason. The infighting in Jerusalem and the brutality of Antiochus--his massacres and pillaging of Judea sparked the Hasmonean revolt of the Maccabees, familiar to modern Jews from the Hanukkah story. Mattathias and his five sons, including Judah the Maccabee, were cohanim, and there was a twenty-five-year struggle between the Hasmoneans and Seleucids. In 141 B.C.E., Simon, the last of the Maccabee brothers, became high priest and political leader. The cohanim then became firmly in control of both the religious and political life of the kingdom. Of course, the Second Temple was destroyed by the Romans in 70 C.E., with large numbers of Jews exiled after falling to Titus's army.
With this history as background, Goldstein considers two different scenarios, that of adoption versus genetic continuity of the priests.
The Jews have long carried with them the story of the priests, and at some point in their history these stories could have motivated people to assume, or adopt, priestly status, regardless of their genetic ancestry. In other words, sometime after the dispersal in the first and second centuries C.E., a group of Jews (or maybe non-Jews) could have decided to adopt the title of priest or been awarded it. In time, this group could have come to be accepted as such. We know that in the Second Temple period the award of priestly status had everything to do with political expediency and relatively little to do with genealogy.
Realpolitik would certainly favor the scenario of expediency rather than genealogy. But it turns out that science, by mapping the Y chromosome, which marks male gender, and is passed from father to son, tells a very different story. "At the other extreme from this nongenetic adoption of status is the possibility of genetic continuity, which assumes that the oral tradition is largely correct: the cohanim of today are indeed culturally and genetically continuous (on the male side) with the priests who survived the destruction of the Second Temple and subsequent uprisings."
Goldstein rightly reiterates the caveat that he made at the beginning of the book. "In general, genetic history has been successful only in contexts where nongenetic sources of information--for example, texts, oral history, or archaeology--specify mutually exclusive possibilities.... Working without such external information, it would be difficult, if not impossible, to tell a coherent story about the history of a population based solely on genetic data." And so sometimes the necessary research to make probabilistic conclusions about descent moves far out of a laboratory dissecting DNA and comes close to historical and archaeological inquiry.
In order to arrive at an accurate answer to the question of whether the oral tradition surrounding the Jewish priesthood was likely correct, Bradman and Goldstein first had to develop an estimate of the proportion of Jews who might be considered cohanim. "My solution was to keep reading books in the hope that someone had mentioned the issue somewhere," Goldstein writes. "Neil Bradman came up with the better idea: go into Jewish cemeteries and start counting all the headstones with the priestly hand symbol on them. Visit enough cemeteries, reasoned Neil, and you'd get a good idea of the proportion in the general population. In this way, Neil made a casual estimate based on cohanim symbols found in cemeteries in the United Kingdom and elsewhere. I myself spent a brisk morning wandering around the haunting and beautiful Jewish cemetery in Prague searching for the split-finger insignia and feeling a surprising sense of connection to this community of which I knew so little."
Goldstein, like many scientists, does not suffer fools lightly, and he finds much foolish in how this work was communicated to the public. "I keep a folder of various press clippings that mention my work, mostly because my mom and dad often send them to me but also because they are a powerful reminder of the ways in which even modest and speculative research findings get exaggerated and reported as fact," he writes. "For me, the cohanim study and the 'Aaron's Y chromosome' headlines it generated represent one of the more egregious examples of this phenomenon." The Independent on July 9, 1998, stated that "Jewish line traced back to Moses. The Jerusalem Report on May 10, 1999 said that there was "scientific confirmation of an oral tradition passed down through 3,000 years." In Goldstein's mind, "it is striking enough that the Y chromosome could provide any historical information at all. I thought the story was that genetic history was not total bunk and indeed could add to conventional history, archaeology, and anthropology. But the press has a weakness for grandeur."
There is no way to know whether today's cohanim are indeed carrying Aaron's Y chromosome. All that can be said--and it is quite a bit--is that "our best guess is that the priestly line was founded before the major dispersals of the Jewish populations--that is, certainly before the time of the Romans and perhaps before the Babylonian conquest in the sixth century B.C.E. Whatever their true origins, whomever they may trace to, the cohanim of today are descended from an ancient lineage." But whether that is Aaron, who is placed at the time of the Exodus (which Goldstein points out may not have occurred at all), remains an open question.
The story of the Y chromosome reaches beyond groups identified as Jews. Goldstein moves on to the Lemba, a black tribe in South Africa that, like many, claims descent from the "Lost Tribes" who, following the death of King Solomon in the tenth century B.C.E. and the conquest of the Northern Kingdom of Israel by the Syrians in the eighth century B.C.E., were ten in number and disappeared. Here, again, chromosomal analysis can be helpful. "Since then, at one time or another innumerable peoples from all over the world--Japanese, Native Americans, Indians, Persians, Ethiopians, North African Berbers, Eskimos, and Tauregs [sic] of the Sahara, among others--have claimed descent from one or more of the Lost Tribes."
Here Goldstein expounds on the power of myth in clans and tribes. "Perhaps because it touches something deep within the human psyche--here I'm thinking of the powerful literary themes of home, the return of the prodigal child, grace, forgiveness, and redemption--the myth of the Lost Tribes has persisted," he writes. "So seductive is the narrative that even some otherwise objective and deeply skeptical anthropologists confess a weakness for its.... All of which is to reiterate that, for me, genetic history is not about identifying a Lost Tribe but rather about the broader recurring themes of Jewish history contained within the myth of the Lost Tribes: exile, loss, wanderings, Diaspora, and reclamation of one's heritage. As much as any other piece of Jewish lore, the Lost Tribes story is about the continuing saga of strangers in strange lands."
The Bantu-speaking Lemba are monotheistic, have resisted assimilation, are endogamous, practice circumcision, are buried horizontally (almost all other African tribes bury their dead in a sitting position), practice animal sacrifice, follow a lunar calendar, and observe strict dietary laws akin to kashrut (they do not mix milk and meat or eat pork). Goldstein allows that none of these cultural aspects can be considered "diagnostic"--but again, the whole picture is sufficiently suggestive to hunt for genetic data that could support a link to the Jews. Trefor Jenkins, a South African authority on the genetics of African populations, reported in 1996 that a significant fraction of Y chromosomes of the Lemba was of Semitic origin and not related to other Bantu speakers. Further analysis by Bradman and Goldstein supported Jenkins's early work. Drawing on oral traditions and historical documents, they postulate that the Lemba may have originated in Judea, migrated to Yemen, and then moved to the African continent.
Goldstein's findings, even before they were published in the American Journal of Human Genetics, made the front page of The New York Times in May 1999. This unleashed a flood of publicity about the tribe, and debates about their right of return to Israel, and shipments of religious books and objects. Some Jews traveled to South Africa to bring the group back into the fold. Goldstein reports that in general the Lemba "respectively declined" such offers and preferred to sustain their own "syncretic Judeo-Islamo-Christian existence. " Goldstein blames himself, specifically "my big mouth" for speaking to a reporter after his presentation at the Cold Spring Harbor laboratory on this work. "In retrospect, I found that despite my best efforts I can't control how results from my lab are manipulated by others for their own purposes, be they noble or malevolent. Such are the pitfalls of practicing science so intimately connected to human populations and their sense of identity."
Goldstein includes in this short but masterful book yet another instance of how the popular press distorts scientific studies that are at best premature. Recently, a paper appeared trying to explain why certain diseases termed "storage disorders," such as Gaucher's and Tay-Sachs, are so prevalent among Jews. The work, by Gregory Cochran, Jason Hardy, and Henry Harpending, claimed that individuals with these storage disorders show anatomical differences in the brain, particularly involving the ends of nerve cells. They suggested that there may be more interconnections among neurons in such people. They then hypothesize that such a biology could be an explanation for "Ashkenazi intellect."
Goldstein is properly doubtful about this hypothesis. Intellect is notoriously hard to measure; and it also seems overly simplistic to imagine that mutations in storage disorders were selected for in the Ashkenazi community based on the restricted professions that Jews could enter, such as moneylending, as well as the tradition of Torah scholarship. "Are we prepared to attribute much or most of that scholarly impulse to genes?" Goldstein writes. "Is there a danger that the Cochran-Hardy-Harpending approach will somehow legitimize the pseudoscientific genetic determinism that we as scientists and citizens have spent so long fighting against? Genes are not destiny. Nor would I want to minimize the value of good old-fashioned hard work. As far as I'm concerned, our environment, our choices, our agency are factors we ignore at our peril. I hope that readers of this book will come away from it understanding that genes play a critical role in who we are but they always do so in combination with the environment. And in human populations, genetic and environmental contributions are notoriously hard to disentangle."
This theme is echoed in other scientific work that studied a group which believed it was Jewish but had no genetic markers found in other Jewish populations. Tracing genetic lineage is not restricted to studies of the male Y chromosome. We have DNA in our mitochondria, small organelles that are energy factories in the cells. This mitochondrial DNA is inherited strictly from our mothers, and thus traces a matrilineal arc through time. Goldstein recounts the controversy about the Bnei Menashe members of the Kuki-Chin-Mizo tribes in northeastern India near the Myanmar border, who number some seven thousand. Like the Lemba, they have for generations observed strikingly Jewish-like rituals including circumcision and a festival centered around unleavened bread. (Hillel Halkin popularized their story in his book Across the Sabbath River, initially with deep skepticism, and then believing that they may indeed be a remnant of the Lost Tribe of Manasseh.) Genetic analysis failed to demonstrate any "cohanim" Y chromosomes and there was "only equivocal evidence of a Near Eastern origin" using mitochondrial DNA.
Goldstein observes of this skeptical finding that "some commentators took the opportunity to say, essentially, "Ha--told you they weren't 'real' Jews." Then, three years ago, the Sephardic rabbinate recognized them as Jews. Many of them now are making their way to Israel. "In my view, this is a perfect example of when we are best served by ignoring DNA--if living, breathing people want to embrace Judaism, genetics should have nothing to say about it one way or the other." That is the true and ringing message of Goldstein's book.
Genes, as Goldstein shows, are interesting to unravel and fun to study. But they are emphatically not destiny. We make existential choices about how we live and what we pass on as culture and values to our children. Judaism has long embraced this; indeed, it pioneered in the invention of tradition and the duty of its transmission. Despite dynastic currents, bloodlines can be established based on character and commitment. King Saul stumbles in his duties to Israel and God and his progeny are no longer royal. Ruth is a Moabite, a tribe that sorely vexed the Hebrews, but Ruth famously follows her mother-in- law Naomi and so elects to be part of the Jewish people--and it is Ruth's line that spawns David and therefore, according to the tradition, the Messiah.
The great and beautiful irony is that this ancient assessment of position and potential in society, this hostility to biological determinism and respect for free human choice and its consequences, is also at the core of modernity. It is refreshing to have this truth now affirmed, and in this context, by a geneticist. In his typically wry tone, Goldstein remarks, "Forced to choose between Jewish mothers and Jewish genes, I'll take Mom every time." Perhaps that is why my mind moved so far from my own clan and remembered my poor patient, the scion of New England Puritans. David Goldstein's inclination is splendidly universal. Deeds rather than descent are what define a person.
By Jerome Groopman