DNA and Biblical Priests
From the BASNY Explorer
According to biblical tradition, Jewish priests were descended from a
single male ancestor, presumably Aaron himself, with the title handed
down from father to son. Because certain genetic traits are passed
through the male line by the Y chromosome, some researchers realized
that if the biblical claim were true then persons descended from the
Jewish priests should share certain genetic characteristics. With
this idea in mind, a genetic research time set out to test the hypothesis.
To begin testing they needed a way to determine which Jews were
descended from Jewish priests. In an article in Nature magazine, Dr.
Michael Hammer, a geneticist at the University of Arizona, described
the methodology and conclusions.
Although Jewish names such as Kahn or Kahane are generally thought to
signify a connection to the Jewish priesthood, the researchers did
not use surnames as the basis for selecting the genetic pool.
Instead, they asked 188 Jewish men from Israel, North America and
England if they were told that they were descended from priests.
Sixty-eight said they were and the rest described themselves as
Israelites, implying a lay status. (Those describing themselves as
Levites, signifying a different priesthood, were omitted from the study.)
The biologists then extracted genetic material from each of the
individuals and looked for known markers in the DNA structure. One of
the first propositions to be tested was whether or not there were any
significant differences between the genetic makeup of the
self-identified priests and the rest of the group. Astonishingly,
there were differences. Only 1.5 percent of the priests had a
particular genetic marker while 18.4 percent of the laymen had the
same marker. A second marker showed up in 55 percent of the priest
group and only 33 percent of the lay group.
The results suggested a strong possibility that the line of Jewish
priests did indeed have a common male descendant, but how far back
that common ancestor might be is hard to say. Dr. Karl Skorecki, a
genetic researcher in Haifa and co-author of the study, believes that
the data points to Aaron as the first priest in the line. While the
precise time frame for the origin of the genetic line remains to be
determined, the preliminary evidence does suggest that the genetic
trait precedes the division of Jews into Ashkenazic and Sephardic
lines, an event that goes back at least about 1,000 years. Similar
genetic markers were found among the priest groups of both factions.