Tracing your lineage back to Aaron, the first High Priest
In Hebrew, the word for priest is kohen (ko-hayn). The popular Jewish surname Cohen comes from this word, as do surnames like Kahn and Kahane. Although not completely guaranteed, it’s usually the case that a Jewish person with one of these names is a descendant of the original priests — and therefore of Aaron himself. The status of the kohen is passed down in a patrilineal way (from father to son), and an unbroken chain exists for 3,300 years and more than 100 generations! In fact, in the synagogue Torah service (see Chapter 13), the first person to be called to the Torah during its public reading is a direct descendant of Aaron. As amazing as it seems, Jewish families today usually know if they descend from Aaron or from the Levites. A Jew who isn’t a descendant of either is consider an Israelite.
Genetically, if two people have the same ancestor, a genetic marker is present in both of their DNA. An article published in 1997 in the highly regarded science journal Nature reported that DNA analysis revealed that, of 188 Jewish men who had been told that they were descendants of Aaron, 98.5 percent of these men shared the same ancient genetic marker. Since that report, many other studies have been done and indicate a clear tradition of shared descent among most of those today who claim descent from Aaron.