Experts discuss common pitfalls and share their strategies for success
Autosomal DNA testing has become a standard tool used by many genealogists, and it has helped people discover unknown Jewish ancestry. But using autosomal DNA in Jewish research is filled with challenges, due in large part to the Jewish Diaspora and a long history of endogamy (marrying solely within one’s community). Jewish AncestryDNA users often discover thousands of cousin matches and an ethnicity category that stretches from Germany, across Eastern Europe, and well into the western half of Russia. It may feel overwhelming at first, but it is possible (though not easy) to break down brick walls in Jewish research using DNA.
Janette Silverman specializes in Jewish research at AncestryProGenealogists, and she and her team have used DNA to solve cases for clients. “You have to be able to first take a few deep breaths when you’re doing this kind of research, and you also have to be really patient,” she said. “I think you need to understand the issues that cause the challenges (in Jewish genealogical research), which will help inform how to use DNA.”
Diaspora and Expulsions
Unlike other dispersed groups, the Jewish community has been scattered across the globe for more than 2,000 years. They settled in Babylonia after being exiled from Israel about 2,600 years ago, followed by a second exile about 2,000 years ago that resulted in a diaspora scattering the Jewish population across Europe, Africa, and Asia, and ultimately around the world.
“You wound up with pockets of people who settled in different areas; and because of persecution, economic interests, or other reasons, they weren’t tied to wherever they were living,” Janette said. “So, they were moving around, and they were moving around in family groups, for the most part.”
Starting in the 12th century, Jews all over Europe endured waves of expulsion lasting into the 20th century. Distinct communities were forced out of the areas in which they had settled and intermixed with each other, according to Josh Perlman, a specialist in Jewish research who works on Janette’s team. A large number ended up in what was the Polish Lithuanian Commonwealth, because that was one of the only places they were allowed to settle. The Ottoman Empire was the other major destination that accepted Jewish refugees.
Although AncestryDNA’s new Genetic Communities can pinpoint some ethnicities to very specific locations, down to a county level in some places, it is a different story for a population, like the Jewish communities, that didn’t remain in one place. Due to the dispersion of the Jewish community, AncestryDNA’s “community” for European Jews generally covers a huge territory. Ashkenazi Jews are categorized as being from either “Central Europe” or the “Russian Empire.” To demonstrate how convoluted the relationships are, Jews from the Russian Empire are divided into three subgroups that inhabit the same geographic area: Lithuania, Latvia, Belarus, Ukraine, and Poland. This was the area ceded to the Russian Empire during the partitions of Poland in the late eighteenth century, referred to as “the Pale of Settlement.” To confuse things even further, the Central European Jewish communities overlap, to some degree, with those of the Russian Empire in Poland and Ukraine.
These classifications into Central Europe or the Russian Empire can give a person some vague idea of where their families were from, by dividing the European Jewish ethnicity into two somewhat distinctive groups. One interesting group is that which combines the Benelux countries. This is composed of a relatively small population, and by separating it from the larger population, someone whose DNA community is defined within it can more specifically identify their family’s place of origin. However, the lack of distinction in the other areas reinforces what has become evident through documentation, and that is the notion of the Jewish community as a migrant population.
Compounding this lack of specificity in place is a long history of endogamy. Jewish law allows cousins to marry, and in some families, this occurred over many generations. As a result, it’s common for Jewish AncestryDNA users to have thousands of matches whose relationships can be difficult to determine. “It looks like you’re more closely related than you actually are, because you’re sharing more DNA than you would normally share,” Janette said. For example, you and a match may share enough DNA (measured in centiMorgans) to look like first cousins, when in fact you are really second or third cousins with the same common ancestor appearing on multiple family lines.
For this reason, Janette and her team don’t use DNA matches beyond the third cousin level when trying to establish the most recent common ancestor in a client’s family tree. The issue with going back beyond third cousin matches in the Jewish community is the lack of specificity regarding relationships. For example, a relationship in a Jewish match that appears as a third or fourth cousin may really be a sixth or eighth cousin because Jews may be related through several branches of their family due to endogamy. And of course, documentation is vital in confirming these relationships.
Tips for Success
- Build your tree, make it public, and attach the DNA test (whether it’s yours or a test you have administered for someone else) to the correct person in the tree. This allows your matches to compare their tree with yours, making it easier to determine how you might be related.
- Identify the names used by your ancestor as an immigrant and their European hometown using birth, marriage, or death records in the United States. Always look at the original records, which will have more information than an index. Be aware that people often named a larger, nearby town rather than the smaller locality in which they actually lived. Search all the records to be as specific as you can.
- Once you have defined the European hometown as much as possible, you may need to enlist the help of researchers who work in those areas. “You need somebody digging in the archives who has lots of experience with that particular archive,” Janette said.
Only once you have taken your tree back as far as you can get it should you look at cousin matches.
- Start with those matches that have trees attached to their DNA results. You might get lucky and find a tree that goes back far enough to identify the common ancestor. However, it’s more likely that you will need to do more research on that person’s tree in hopes of finding a common ancestor. You can also use the “Shared Matches” feature to identify who your matches share in common.
- Search your DNA matches by surname and look at their trees. Do you see a common ancestor in your tree and a match’s tree? Is the relationship and the amount of DNA shared a little closer than the actual relationship you expect to have with this person? Do the places and documents in their tree match those in your tree? Search for clues that it is in fact a common ancestor, rather than someone with a common name that isn’t your ancestor.
For a more in-depth discussion about interpreting autosomal DNA test results, read this article from the International Society of Genetic Genealogy. And, stay tuned for more articles about Jewish genealogy on the Ancestry blog.