PRIESTLY GENES

About 3300 years ago the Jewish tradition of the Kohanim (priests) was founded.  God instructed Moses: "Bring near you Aaron and his sons with him from among the Children of Israel to minister to Me" (Exodus 28:1).  Since that time, the heritage of the Kohen has been passed from father to son, generation after generation, to this day.
If all the Kohanim descend from one man, do they have common genetic markers?  Amazingly, the answer is positive.  A DNA study of Jews from North America, Britain and Israel (see Nature, vol. 385, 2 January 1997, p.32) has found clear differences in the frequency of certain male Y-chromosome haplotypes (neutral mutations of the DNA) between Kohanim and lay Jews.
 Furthermore, the same significant differences in the genetic markers were found for Ashkenazi and Sephardi Jews, indicating that the genetic markers predate the diaspora.  The genetic mixing that has taken place in the diaspora over the last 2000 years has affected the appearance of Jewish people around the world, but the unique Kohen gene is shared.
The Torah states that the priesthood of Aaron's descendants shall be an eternal law (Exodus 29:9).  Indeed, the tradition has been passed faithfully for more than 100 generations.  It is still astonishing that after all these centuries, the genes of Aaron HaKohen are scientifically evident in the Y-chromosome of his male descendants -- the Kohanim.
Judah Ari-Gur

For more columns: http://homepages.wmich.edu/~arigurj