Has Aaron's Y Chromosome Been Found?
According to the biblical chronology, God ordered Aaron to be consecrated as the first priest of Israel about 3,400 years ago. From Aaron, priesthood was passed down from father to son until the official priesthood ended with the destruction of Jerusalem in 70 AD. After that, fathers would tell their children that they were descended from the priestly class. Though only these oral histories exist today, modern Judaism still honors Aaron's descendants. Today they are called cohanim, which is the plural of cohen, meaning "priest" in Hebrew.
A modern geneticist wondered if there was any way to prove the oral history. He reasoned that if all cohanim today are descended from Aaron, and if the oral history is true, modern cohanim should share some distinctive sections of DNA on their Y chromosome. The Y-chromosome is always passed down from father to son virtually unchanged. His first study involved two genetic markers of 188 Jewish men from Israel, Canada and the United Kingdom. Of this number, 68 said they were cohanim. The results of this first study showed that the cohanim share Y chromosome material that is quite distinct from other Jews. A second study involving 12 markers on the Y chromosome of 306 Jewish men gave similar results: the cohanim did have a distinctive Y chromosome. This chromosome evidence strongly indicated that the biblical and modern oral history of the Jewish priesthood are completely trustworthy.