Project Genesis

Basics of Judaism

Who is a Jew?

Unwitting Jews and DNA Testing

Question: Since Judaism is passed through maternal lineage, the children of a woman who strays from Judaism will be Jewish without their knowledge. Her daughters will marry, and they will have children who are Jewish without their knowledge. This can happen for many generations, with all of the women creating Jewish progeny – although they don’t know it!

Additionally, with the ten lost tribes out there somewhere, ignorant of their true heritage, it seems that an effort should be made to encourage people to get DNA tested, and return to God and Israel if they test positive. What do you think?

Answer: Since Judaism is not racist and allows all who are sincere to join the religion, it is pretty much impossible to come up with genetic markers for being Jewish. Since the Aaronic priesthood passes through the male line, there is a genetic marker for the Priestly tribe. However, this is fairly meaningless today since a person could carry the priest DNA without even being Jewish. Males with the genetic marker could have married non-Jewish women and still pass their DNA on to their non-Jewish sons.

In theory, you are right that there are probably millions of people in the world who have Jewish blood. Since they are unlikely to be able to trace their Jewish heritage in an unbroken maternal line, it is not of practical significance. You can also consider the hundreds of thousands, if not millions, of descendants from those Jews in Spain and Portugal who were forcefully converted to Catholicism, but remained genetically Jewish. Many of these Jews are finding their way back to Judaism in our times.

Rabbi Michael Katz

2 Follow-ups »

  1. I was under the impression that after three generations of not practicing Judaism, individuals born in the once-Jewish family were no longer considered Jews.

    That is not correct. As long as the Jewishness is being passed on through the maternal line, it will not disappear regardless of the commitment of the family to being Jewish.

    Comment by ATR — May 4, 2008 @ 11:22 am

We respond to every follow-up question submitted, but only publish selected ones. In order to be considered for publication, questions must be on-topic, polite, and address ideas rather than personalities.


Powered by WordPress