Finding a Family’s Jewish Ancestry

As the series Finding Your Roots with Henry Louis Gates, Jr. begins its 10-week run on PBS, The Spittoon will feature posts from 23andMe’s Ancestry Ambassadors featuring their own stories about using DNA to dig into ancestry. By Andrea Badger

There has been a legend in my family, passed down from generation to generation, about my third great-grandfather Nathaniel Lewis. According to family folklore, his name wasn’t originally Nathaniel Lewis, but rather, Nathaniel Levi. As the story goes, our Lewis ancestors were Jewish people who converted to Christianity and changed their name from Levi to Lewis. I had always wondered if this family story was really true. Everyone in our family has been told this legend but no one really had any conclusive evidence — just small clues. My grandmother and her siblings remember their mother singing Jewish songs to them as children. We also have an old newspaper article about our ancestor that states in passing ‘Nathaniel Lewis has lived in Scotland for many years but has no Scot’s blood’. Many of my relatives have speculated that this statement reveals that although Nathaniel was of Scottish nationality, he had a different ancestral background — Ashkenazi Jewish. However, conclusive evidence about this hypothesis was lacking until I joined 23andMe.

When I first joined 23andMe in 2009, Relative Finder was just being introduced and the Ancestry Finder feature did not yet exist. As I corresponded with my Relative Finder matches, I noticed that many of my potential relatives said that they were of Ashkenazi Jewish descent. I wondered if this high number of Jewish Relative Finder matches was typical for someone with Northern European ancestry, so I turned to the 23andMe community for help and posted my questions on the community forums. I communicated with fellow 23andMe users and quickly realized that my genetic profile wasn’t typical for someone without any Jewish background. Instead, my DNA confirmed the old family story and indicated that it was highly likely that I do have Jewish ancestry.

Here is my Ancestry Finder, with the settings set to focus on the Ashkenazi Jewish segments. The blue spots are regions where a 23andMe customer shares a segment of DNA with me AND has stated that he or she has Jewish ancestors..

I decided to get my great-aunt & great-uncle from that side of the family tested, to see if they also had evidence of Ashkenazi Jewish admixture. Right around this same time, Ancestry Finder, which has a specific section dedicated to Jewish ancestry, was introduced. This feature was also immensely helpful in my quest. As I expected, my great-aunt & great-uncle also showed significant Jewish ancestry — more than I have, because they are two generations closer to our Jewish ancestor than I am. For the first time, thanks to DNA testing, we actually have clear evidence of a Jewish ancestor in our past. Without 23andMe, I might never have known if there was any truth to this family legend. Why did the Lewis family feel the need to convert from Judaism to Christianity and change their name? I am actively searching to uncover this information, but much of Nathaniel Lewis’s life story has likely been lost to history. However, his DNA lives on in his descendants and provides clues about his background. Often, when traditional genealogy methods fail, you can turn to DNA to uncover more about your ancestral heritage. You never know what sort of surprises can be uncovered!

When she is not performing genetic comparisons on Family Inheritance Advanced or answering questions on the 23andMe community forums, Andrea Badger attends college at the University of Washington and will be receiving two bachelor’s degrees in June of this year. She writes the genetic genealogy blog at
  • Joel F Peres

    Thanks for your contribution Andrea, before 23andme, I didn’t think that Jewishness could be ascertained by way of DNA, as its a religion. However, one look at my Relative Finder proves that the quirky Family Legend about us having a Jewish past is true beyond a reasonable doubt. Andrea, thanks again for being an Ambassador and for your all around contributions to the land of 23andme.

  • Ponto

    Nice story. At least one family legend proven. I consider more needs to be done regarding Jewish origins in Europeans particularly for those of Sephardi Jewish origins. Iberians, Italians, Greeks and Latino Americans all believe they have Sephardi Jewish ancestry but cannot prove anything at 23andMe. It would be nice for those natioanalities and ethnic groups if something could be done for them. By the way many Jews that went to the Netherlands and Britain were originally Sephardi Jews not Ashkenazi Jews.

  • Liliana

    Interesting post! I have also used the advanced controls with this feature due to some of the matches on RF that piqued my curiousity and some family stories. I did find some blue spots on three segments at 5cM. How far might this ancestry go back based on this (newbie question:) Thanks for any insight!

  • I am carrying reseach on Jewish genomic DNA over 15 years, meical aspects. ancestry and other.

    I came to the conclusion than globally about 300 000 000 indidviduals carry significant portion of Jewish ancestry DNA. Therefore andrea’s result does not surprize me at all!

    If interested, please write to me

  • If interested in Jewish DNA, please read

    Professor of Comparative Genomics, Latvian University, Riga

  • Mary Jean Flanagan

    I would like to know more about this and how to go about this.

  • Arthur

    As all those interested in genealogy and genetics realize, it just takes one intergroup relationship to change an ingredient of the genetic-ethnic profile. Since the Ashkenazic Jewish community was in Europe for over 1000 years, there would be enough who dropped out of the community and joined the surrounding populations to cause many Europeans to have a small amount of Ashkenazic Jewish ancestry. And since it was often considered desirable to conceal Jewishness, because of the stigma attached, this discovery from DNA may often come as a surprise to their descendants. But more surprising would be the cases when a much higher percentage shows such connections, that would indicate information about a much closer ancestor.