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Lost Tribes of Israel

Blessing Using genetic analysis, experts can trace the male members of the Jewish priestly line known as the Cohanim many centuries back into the past.
Tracing the Cohanim
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Most men can only name their male ancestors going back a few generations. Members of the Jewish priesthood (Cohanim) are an unusual group in that the men of this ancient priestly class can claim descent from a single male ancestor.

According to biblical accounts, the Jewish priesthood began about 3,000 years ago when Moses anointed his older brother Aaron the first high priest. Ever since, the priestly status has been handed down from father to son through the ages.

If this hereditary tradition has been closely followed, the Y chromosomes of the Cohanim today should bear some resemblance to one another because of their unbroken link back to a common ancestor, Aaron.

Genetic studies among Cohanim from all over the world reveal the truth behind this oral tradition. About 50 percent of Cohanim in both Sephardic and Ashkenazic populations have an unusual set of genetic markers on their Y chromosome. What is equally striking is that this genetic signature of the Cohanim is rarely found outside of Jewish populations.

Gene scans Gene-scan outputs of microsatellite DNA analysis of genetic samples taken from a Lemba (top) and a member of the Cohanim. See larger version (38k)

The Y chromosome also keeps track of time. Small mutations occur in the DNA being passed on, and these changes build up with each generation. Like the tick of a clock, the number of these mutations is a measure of time passed. By looking at the differences between Y chromosomes in the Cohanim, researchers can estimate roughly how many generations ago members of the priesthood had a common ancestor. Remarkably, the evidence suggests the Cohanim chromosomes coalesce at a date that corresponds with when the priesthood is thought to have begun.

What researchers may have found is a marker indicating paternal connection to the people from whom the ancient Hebrews emerged—potentially a powerful tool that enables us to look into the history of many Judaic populations.

Continue: The Lemba
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