NEW YORK, N.Y., and HAIFA, Israel, July 9, 1998 -- The finding last year of genetic links among Jewish men thought to be descendants of the Biblical high priest Aaron was greeted with tremendous interest and clamoring for more information. A team of British and Israeli scientists have now found additional information that links the priestly cast, the Cohanim, which includes men with last names that are variations on "Cohen."
Using a combination of molecular genetics and mathematical analysis, the scientists arrived an an estimated date for the most recent common ancestor of contemporary Cohanim. According to this analysis, the common ancestor lived between the Exodus (approx. 1000 B.C.E) and the destruction of the first Temple (586 B.C.E.), consistent with the biblical account. Similar results were obtained based on analysis of either Sephardi or Ashkenzi communities, confirming the ancestral link of the two communities which had been separated for more than 500 years.
The study by Prof. Karl Skorecki of the Technion-Israel Institute of Technology and Rambam Medical Center in Haifa, and colleagues at the Rambam Medical Center, Oxford University, University College London and University of London is published in the July 9 Nature.
The findings received an added boost when the researchers discovered that by contrast, the Y chromosome of many contemporary Levites, descended from the the tribe of Levi of which Moses was a member, display distinct sets of genetic markers, suggesting a heterogeneous pattern of descent which does not reflect a single pattern of direct paterilineal lineage.
The findings are based on the analysis of genetic markers in the DNA of Y-chromosomes of Jewish male priests from different countries of origin in comparison with their Jewish male Levite and lay counterparts.
The Y-chromosome is uniquely useful in this analysis because the Y-chromosome of any individual can be traced back even over many generations to only one male ancestor. This is not the case for other chromosomes, each of which carries representation from many different ancestors on both the maternal and paternal lineages. Accordingly, since the Jewish priesthood designation is transmitted from father to son, the DNA of the founding ancestor is reflected in the Y-chromosome markers of modern-day Jewish priests.
To date the original high priest, the research team used a formula based on a commonly accepted mutation rate. This formula yieded some 106 generations for both Ashkenazi and Sephardi Jews, or between 2,650 and 3,180 years, depending on whether a generation is counted as 25 or 30 years.
Since biblical tradition dates the establishment of the Jewish priesthood to roughly 3,000 years ago, it may be possible to utilize analysis of the Y-chromosome DNA of modern-day Jewish priests to deduce rates and mechanisms of DNA mutation and Y chromosome evolution.
Furthermore, since the set of genetic markers identified among the Cohanim originates in the ancient Hebrew population, it is possible to use this set of markers to uncover otherwise obscured ancestral or historical links among widely scattered Jewish communities throughout the world today.
In response to a question about genetic testing, Prof. Skorecki emphasizes that this genetic analysis is used to help elucidate questions of general scientific and historical interest and is not meant to be applied to testing of individuals. Furthermore, use of neutral genetic markers rather than genes themselves allows inferences about ancestral and historical relations and reflects no known association with individual human characteristics.
The Technion-Israel Institute of Technology is the country's premier scientific and technological center for applied research and education. It commands a worldwide reputation for its pioneering work in communications, electronics, computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine, among others. The majority of Israel's engineers are Technion graduates, as are most of the founders and managers of its high-tech industries. The university's 11,000 students and 700 faculty study and work in the Technion's 19 faculties and 30 research centers and institutes in Haifa.
The American Technion Society (ATS) is the university's support organization in the United States. Based in New York City, it is the leading American organization supporting higher education in Israel. The ATS has raised $650 million since its inception in 1940, half of that during the last six years. Technion societies are located in 24 countries around the world.
Journal
Nature