Jewish DNA
Many researchers are seeing suggestions of unexpected Jewish ancestry in their DNA test results. Emma Jolly explains what she did when it happened to her
Emma Jolly explains what she did when the result of her DNA test revealed unexpected Jewish ancestry
The popularity of DNA testing for family history has soared recently. In January 2019 news website GenomeWeb ( genomeweb.com) published a report indicating that approximately
30 million people worldwide will have taken a direct-toconsumer DNA test by the end of 2018. Tests are now cheaper than ever, while also being easy to buy online and even on the high street. It is through these tests that many of us (including me) have discovered that we have Jewish ancestry. This raises the question of how we can find the truth about our Jewish ancestors. We also need to ascertain whether we can be sure from these tests that we truly are descended from Jews.
Firstly, we should look at the tests themselves. Most tests sold in the past year were for
‘We may find some surprises in our ethnic origin estimate reports’
autosomal DNA (atDNA), as opposed to Y-chromosome DNA (Y-DNA) and mitochondrial DNA (mtDNA). These can be taken by men or women, and check the DNA inherited from autosomal chromosomes. The nature of atDNA inheritance means that although you will have segments from all your ancestors up to at least your 3x great grandparents, as you go further back you will find there are some ancestors you share no DNA with.
In family history, we use atDNA primarily for three aims: to find matches with our genetic cousins; to identify our recent ethnic origins; and to discover information about our health.
It’s important to shop around and be clear why you are testing, because the various testing companies offer different options. Most do not currently include a health option, for example. Finding DNA relatives (cousin-
matching) and exploring ethnic origins tend to be stronger motivators for buying DNA tests. Yet both these aspects of genetic genealogy can be misunderstood.
Increasingly, as more of us receive our test results, we may find some surprises within both our cousin matches and our ethnic origin estimate reports. This confusion can be complicated by articles and anecdotes shared on social media about people’s experiences of DNA testing. I have lost count of the newspaper reports I have read in the past year of testers who have found long-lost parents or siblings through DNA tests. Some of these testers were looking specifically for a missing relative, but there are growing numbers of reports of recipients of Christmas presents or those with a general interest who do not fully understand what their test may reveal.
Ethnicity Enigma
While surprise relatives dominate these kinds of stories, unexpected results in ethnic origin estimates tend not to be regarded with as much excitement. And while the DNA evidence of a close relative can be proved, the estimates of where our ancestors originated are often clouded in confusion.
When considering ethnic origin results from atDNA tests, it is important to remember that this DNA is inherited randomly from our ancestors, meaning that siblings can show a different inheritance in a test. A common area of uncertainty, for example, is when a brother is showing a larger estimated percentage of, say, Ashkenazi Jewish DNA than his sister. This is as a result of him having inherited more
DNA from their most recent
Ashkenazi ancestor (for example a great grandparent).
This random inheritance (or non-inheritance) means that we don’t always get exactly 12.5 per cent of DNA from a great grandparent, for example. In my case, if I have an Ashkenazi great grandparent, the percentage of Ashkenazi DNA I inherit may form only 8–10 per cent of my ancestry – with other ancestors being over-represented instead.
Currently, the ethnic origin part of DNA test results is not an exact science, and there are continual developments. If you took a test over a year ago, you may have noticed changes to your ethnic origins even in this short period. 23andMe ( 23andme.com), for example, released an update to its Ancestry Composition Guide just a few weeks ago.
Another problem is specific to Jewish DNA, in that it is distinct for being based on an ethnic diaspora or population community group, rather than on geographic origins (ie where people lived). This has led to further questions about where Jews originate geographically.
Indeed, there are many complexities surrounding Jewish DNA, including endogamy (see box, left). This makes it an especially tricky area to research.
Ashkenazi Origins
So far, I have mentioned only Ashkenazi Jewish ancestry.
In the UK and the USA, the Jewish populations are mostly Ashkenazi. They are descendants of the Jewish diaspora who were recorded in the Holy Roman Empire around the time of Christ’s birth. Ashkenazi Jews migrated into Germany and France in the Middle Ages, and it was in this period that they developed the Yiddish language (a mainly Germanic language with elements of Hebrew and Aramaic). Towards the end of the Middle Ages, religious
persecution led most Ashkenazi to move into Eastern Europe, where they settled in modern-day Russia, Ukraine, Poland, Latvia, Belarus, Lithuania, Moldova and the Czech Republic.
Sephardi Jews trace their heritage to the Iberian/Spanish peninsula of at least the 15th century – well-known Sephardi Jews in British history include prime minister Benjamin Disraeli (1804–1881). Sephardi Jewish ethnicity is identified in DNA tests by FamilyTreeDNA ( family treedna.com) and MyHeritage ( myheritage.com). The latter also identifies Mizrahi Jews (from Iran/Iraq), Yemenite Jews and Ethiopian Jews.
Flight From Danger
From the 1880s until the early 20th century, Britain saw swathes of immigration of Jewish refugees escaping the Pogroms of Eastern Europe. Approximately 140,000 Ashkenazi Jews settled in Britain during this period. Most lived in major cities, such as London, Manchester and Leeds. Others, like my great great grandfather, were merchants who traded in smaller urban areas, such as Bristol and Merthyr Tydfil.
Such a rapid influx of migrants was not welcomed by many, and the 1905 Aliens Act introduced immigration controls for the first time. Many Jews experienced prejudice and discrimination, and were keen to assimilate. Established families may not have welcomed Jewish spouses for their children, so where people did intermarry, the Jewish side of the family may not have been mentioned to future generations. For this reason, many of us have never been told of our Jewish ancestry. Hence the number of Jewish heritage discoveries being made via DNA testing.
Testing For Jewish DNA
The largest companies that provide tests for cousinmatching and ethnic origins are FamilyTreeDNA, AncestryDNA, MyHeritage, Living DNA (with Findmypast) and 23andMe. I have tested with FamilyTreeDNA and Ancestry, and uploaded my raw DNA data to myheritage.com, livingdna.com, 23andme.com and the free site DNA Land ( dna.land). Living DNA is keen to stress that its results focus on where people have lived, rather than on ethnic population groups such as Jewish Ashkenazi. Therefore Jewish DNA is not flagged up in the company’s algorithms.
To illustrate the differences between the testing companies, here are my Ashkenazi Jewish percentages from the five sites:
FamilyTreeDNA:
Ashkenazi, 7 per cent
Ancestry:
European Jewish, 9 per cent
MyHeritage:
Ashkenazi Jewish, 10.3 per cent
23andMe:
Ashkenazi Jewish, 11.4 per cent
DNA Land:
Ashkenazi, 13 per cent
My Ashkenazi results from these sites therefore range from 7 per cent to 13 per cent. From my paper research, I had identified
a gap in my family tree (through illegitimacy) of an unknown great grandfather. The identities of my other great grandparents have been confirmed through paper research, and continue to be double-checked through cousin matches from my various DNA tests. The 7–13 per cent range of my Ashkenazi ethnic origins fits well with the amount of DNA I would have inherited from an individual great grandparent.
Some of the websites have tools that can be particularly helpful for working with Jewish results. For example, 23andMe offers a ‘Your Ancestry Timeline’, which indicates how many generations ago your most recent ancestor was for each population (ethnic group). According to this, I “most likely had a grandparent, greatgrandparent, or second-greatgrandparent who was 100% Ashkenazi Jewish. This person was likely born between 1860 and 1920.” This also seems to confirm that my Jewish ancestry could come from a great grandfather.
Following The Trail
Since estimates of ethnic origins vary, it can be difficult to know if you genuinely have Jewish DNA. In some cases, the estimate can result in researchers looking for a nonexistent Jewish ancestor. My personal recommendation is that if your results show over 5 per cent, you should investigate further. Taking another test, or transferring raw data to another database, is a sensible move. However, if there is less than 5 per cent, it may be a false positive. If you have an idea where the Jewish DNA may come from and have a parent or other relative from an older generation available to test, this could be a better option.
The good news is that even if only a small percentage of your DNA comes from Jewish ancestors, you can usually narrow down which relatives match with these ancestors by finding out which DNA cousin matches also share a similar percentage of Jewish DNA. Most DNA databases are dominated by people based in the USA, so you need to establish whether they have identified any Jewish ancestors living in the UK. Use clues, such as the birthplace of an illegitimate ancestor, to establish where your Jewish ancestor may have been living on a certain date. You can then examine the online trees of any matches, and identify those Jewish relatives who spent some time in this country.
If, like me, you pinpoint where your Jewish ancestry comes from, it can open up a new avenue of research and offer fresh insight into your family’s history.
‘Some researchers go looking for a nonexistent Jewish ancestor’