Kohanim's Genetic Link and Direct Lineage from a Common Ancestor

In Sunday school we were told that all Kohanim are direct descendants of Moses’ brother Aharon. And we learned that the patrilineal line of the Kohanim has been passed from father to son since the time of Aharon - 3,300 years ago or for more than 100 generations. Little Karl must have been one of those kids in Hebrew school who felt the need to question.

Years later, after little Karl became Dr. Karl Skorecki - director of Nephrology and Molecular Medicine at the Technion Faculty of Medicine, he decided to test the idea that he and other Kohanim worldwide share a common ancestor. If Kohanim are descendants of one man, they should have a common set of genetic markers--that of their common ancestor Aharon HaKohen -- at a higher frequency than the general Jewish population.

Skorecki’s tests found that a particular array of six chromosomal markers were found in 97 of the 106 Kohens tested. This collection of markers has come to be known as the Cohen Modal Haplotype (CMH). The chances of these findings happening at random is greater than one in 10,000.

The finding of a common set of genetic markers in both Ashkenazi and Sefardi Kohanim worldwide indicates an origin pre-dating the separate development of the two communities around 1000 C.E. Date calculation based on the variation of the mutations among Kohanim today yields a time frame of 106 generations from the ancestral founder of the line, some 3,300 years, the approximate time of the Exodus from Egypt, the lifetime of Aharon HaKohen.

Skorecki’s research has provided scientific proof of a clear genetic relationship amongst Kohanim and their direct lineage from a common ancestor.