As members of relatively small, cohesive populations, Jews have caught the attention of molecular anthropologists, much as Basques and Icelanders have. Thus, Jewish men who reported being descendants of ancient Jewish priests (Cohens) were found to display distinctive patterns of Y chromosome polymorphisms1; the common ancestor of these "Cohen" chromosomes was dated back to the Old Testament era of about 2,600 to 3,200 years.2 A clan of the Lemba, a black group in southern Africa that claims Jewish descent, was recently shown to have a Y pattern characteristic of Cohens.3
In a paper published last month, an international team of researchers used Y polymorphisms to examine a broad swath of Jewish populations.4 Harry Ostrer, a member of the team and director of the human genetics program at New York University School of Medicine, recalls the questions motivating the study: "What is the degree of relatedness among Jewish populations? Did the ...
