Saturday, August 11, 2012

Ancestry's New DNA test: A Jewish Perspective

This entry is not a religious perspective on the ethics of DNA testing.

This entry is a perspective on's new DNA test from someone of European Jewish descent. This may apply to similar tests from other companies, but not having taken those tests, I am unable to say.

I believe Jews of mostly European descent will find the test less useful for them than for others. I found the results mostly useful for my 25% non-Jewish ancestry.

This is the test that determines one's DNA ethnicity breakdown. This of course can differ significantly from the breakdown of ethnicity of your ancestors in your genealogy database.  Each child receives 50% of their DNA from each parent, but it's a roll of the dice which 50% is passed on.

Theoretically, someone could have none of the DNA from one of their four grandparents.  For example, the 50% from your father might be just the DNA your paternal grandfather passed to him.This is unlikely, but it is also probably unlikely that one has exactly 25% of their DNA from each of their four grandparents. And it's even more unlikely that one has exactly 12.5% of their DNA from each of their eight great grandparents. As one goes further back on their genealogy chart, it becomes more likely that significant portions of your ancestors aren't represented in your DNA.

With that in mind, here are the results I received after submitting my saliva sample recently

From the perspective of my genealogy database, I am 75% Eastern European Jewish and 25% a mixture of European descent (Mostly British, German, and Dutch) and possibly some Native American.  So learning that my DNA is 70% Eastern European/European Jewish isn't much of a surprise.  However, I wasn't aware that that was all the DNA test was going to reveal about 3/4 of my ancestry. It certainly does reinforce the notion of Judaism as a Tribe, though it appears there is enough genetic variance to distinguish between European and non-Euopean ancestry. Looking at the charts of some other people, it appears those of Middle Eastern (Mizrahi) descent aren't 'religiously' tagged.

There are no Scandinavians in my family tree, but that's probably because I haven't gone back far enough.  My mother's Mitochondrial DNA test categorized my matrilineal line as Clan Ursula - which certainly has Scandinavian roots.

Ancestry does note:
Your genetic ethnicity reveals where your ancestors lived hundreds—perhaps even thousands—of years ago. This may update over time as new genetic signatures are discovered.
The rise of the Viking culture spread Scandinavian ancestry far throughout Europe. Their earliest coastal voyages took them to Scotland, northeastern England and established the settlement of Dublin, Ireland. As their power continued to grow, the Vikings spread farther afield, down the Volga River in Russia, to the coast of France and Spain.
So 17% of my DNA comes from some Scandinavian ancestors who migrated to either Britain, the Netherlands, or Germany. The 11% uncertain might contain what little Native American DNA I have, and perhaps some of the Alien DNA some of my friends suspect.

In their FAQ Ancestry explains:
Some people may have a percentage with ‘uncertain’ in their genetic ethnicity results. This means that small traces of a specific genetic population have been found in your DNA, but the probability levels were too low to pinpoint it to a specific ethnicity. This is not uncommon, and as more genetic signatures are discovered with a higher confidence level, we may be able to update this ‘uncertain’ percentage of your ethnicity over time.
This may mean that the 11% is a combination of different ethnicities, none of which are large enough to identify with certainty.

So the breakdown for me wasn't very helpful.  Others have had significantly different results. Judy Russell of The Legal Genealogist was very pleased with the specificity of her results.

Cousin Matches

One of the key selling points of the AncestryDNA test is that they will connect you with others who are potential matches.  And Ancestry provides a LOT of matches for me...

Unfortunately, there is a high number of false positives for those of European Jewish descent.

Despite their encouragement, at least for now, with the number of likely false-positives, it doesn't make much sense to me to contact the dozens of potential cousin matches.  Unless there is a shared surname in their online trees, which so far there hasn't been. (I am contacting the Scandinavian matches. There are less of them.)

I also understand that it may be complicated and science-y (is that a word?) - but I'd like to see the complicated, scientific explanation. It might confuse me, but I consider myself intelligent. I'd like Ancestry to include the scientific explanation on their website. summary:
  • Those of mostly European Jewish descent may not find Ancestry's DNA test very useful due to the over-abundance of false-positive cousin matches, and the lack of specificity in ethnic origins. I am unsure if the results are similar on the tests provided by other companies. 
  • I did find my results interesting, and I am in the process of contacting some potential cousins.


Brian Zalewski said...

I had the same surprise when I saw that it said I have 45% Scandinavian ancestry (my post on it.) I also have never traced anything to that area.

I came to the same conclusion. It may be from either the Vikings or the Goths who both were from the area and spread to places where I do have ancestry.

Nice post.

Moriarty1893 said...

I received my results from last month. In my case it showed 37% Southern European, 31% European Jewish and only 8% Scandinavian. I wonder though, if that 31% is Ashkenazi or Sephardic? doesn't specify, so the DNA markers must be the same or, at the least, very closely related. All in all, it was an interesting experience and shed some light on who my ancestors were.

I waiting on my test results from The Genographic Project to see my Y and mtDNA lines. Money well spent if you learn something new about yourself. From what I gather, AncestryDNA's results are much more specific, whereas The Genographic project only breaks down your Ancestry into 9 sub groups (none of which include Jewish). We will see though.

John said...

Thanks for the comment, it made me realize that in my original entry I was interpreting "European Jewish" to mean Ashkenazic, which is incorrect. It covers either Ashkenazic or Sephardic. It only excludes Mizrahic. I have edited the entry to correct for this.

Some of that 37% "Southern European" in your results could be Sephardic ancestors, just as I am sure most if not all of my "Eastern European" is Jewish.