 In a 2001 article in Nature Reviews Genetics, he noted the curious over-representation of lysosomal storage diseases, disorders of DNA repair, clotting disorders, and metabolic disorders, suggesting a possible commonality for selection of heterozygotes for each of these classes of disorders.He also observed that founder mutations for many of these disorders coalesced to the establishment of each of these Diaspora groups, whereas mutations for others arose at earlier points in Jewish history.A series of studies from the Jewish HapMap Project that he co-founded with Gil Atzmon demonstrated that many features of Jewish history could be observed in the genomes of contemporary Jewish Diaspora groups – a higher degree of DNA segmental sharing within and between Jewish groups and admixture with local historical non-Jewish groups.