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Genome Judaism

Genome Judaism

All Jews are connected.


I recently spoke at an event in Toronto, and afterwards, a mother and daughter came up to chat with me. I thought they might want to discuss the evening’s lecture, but they had a more personal issue to broach: they had spent years mapping their family tree and they thought we might be related.

The mother filled me in on some of her findings: she had traced her family back hundreds of years and had mapped many of its members, taking particular delight in telling me about a few who were especially noteworthy or interesting.

I listened, fascinated, but couldn’t help glancing over at her daughter as she spoke. The daughter was about my age, standing patiently listening to her mother’s findings. But to me her face was even more intriguing. She looked so familiar. I was sure that I’d seen her before.

Later, after we had exchanged e-mail addresses and promised to be in touch, it hit me: the daughter was the spitting image of one of the mothers I know from my kids’ Jewish day school. Living in separate cities, in separate countries, unknown to each other, the two women were practically identical.

She and I might be eighth or ninth cousins, according to her mother’s genealogical research, but judging purely by resemblance, she was a much closer relative to the woman from my children’s school whom she never met.

Related Article: Friendship, Love and Unity

All Jews are Siblings

There is a Jewish saying: “All Jews are siblings.” This is intended metaphorically: All Jews, including converts to Judaism, are united by a shared history, culture, religion, and love of God and Torah. We are bound together as if brothers and sisters.

Beyond this, after 4,000 years as a distinct people, we are quite literally “brothers and sisters,” based on a shared genetic pool.

Modern genetic testing bears this out. Scientists have found that Jewish populations all over the world share more in common with each other genetically than they do with other, non-Jewish, populations residing nearby.

This genetic cohesion becomes even more startling when we look at mitochondrial DNA, the genes that are passed down through the mothers’ side. This is particularly relevant, given that Jewish identity is traditionally passed down through the female side.

Scientists have found that Jewish women from all over the world over can trace their descent to approximately just eight women who lived in ancient times.

And when we look at Ashkenazi Jews (of northern and eastern European origin) women, the pool becomes even smaller: fully 40% of Ashkenazi Jewish women trace their ancestry directly to one of only four female ancestors who moved to Europe about 2,000 years ago, around the time of the Roman expulsion of Jews from Israel.

Jewish men have not been left out of the current wave of genetic testing. For example, the biblical Aaron and his descendents (the “Kohanim”) were in charge of the sacrificial service. Membership in the Kohen tribe was – and still is, thousands of years later – passed down from father to son. Amazingly, Y chromosome testing has revealed the existence of a “Kohen” gene: a common set of genetic markers in both Ashkenazi and Sephardi Jewish communities the world over.

Caring for Cousins

My grandmother, of blessed memory, grew up in Vienna. After she was widowed, she married for a second time: a Jewish widower who was also from Vienna.

Once I began to regard everyone as a distant relative, I found it a lot easier to like them.

One rainy day, my grandmother and her second husband worked out their genealogies – and discovered they were distant cousins. I was a kid at the time, and was amazed at this staggering coincidence. I remember my grandparents looking at me with bemused smiles, and telling me it wasn’t so amazing. After all, the Jewish population in Vienna was never very large.

I’ve thought of their words many times over the years. If my grandparents were distant cousins, then it doesn’t seem so strange that many others might be long-lost cousins as well.

Growing up, it was always a special event getting together with my cousins. We might not have otherwise chosen to be friends, but we knew we shared a deep, common bond, and till today we stay fondly in touch.

This mode of thinking has a profound affect on the way I relate to my fellow Jews. Once I began to regard everyone as a distant relative, I found it a lot easier to like them, relate to them, and care for them. I now find myself affectionately relating to others in my community as cousins – whose genetic link I have yet to discover.

The Sages teach us that Jewish unity was a prerequisite for receiving the Torah at Mount Sinai, and will be a prerequisite for the ultimate Messianic redemption. At times, it seems so hard to connect and relate to Jews of all stripes and sizes. Yet modern genetic testing gives us a scientific basis for understanding what our Jewish tradition already teaches: that all Jews are part of one family, one unit.

As the woman I met in Toronto remarked: “It seems we might have a common ancestor.” Indeed we do.

August 20, 2011

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The opinions expressed in the comment section are the personal views of the commenters. Comments are moderated, so please keep it civil.

Visitor Comments: 12

(7) Beverly Margolis-Kurtin, October 29, 2014 4:32 PM

I could care less

IMHO, a Jew is a Jew is a Jew. I love that my ancestors were probably in the first four who headed out to Europe after the Romans tried kicking us out of Israel.
My INTERNAL DNA is meaningless in that I don't feel the need to prove that I am a Jew
Several years ago a woman was all atwitter because some outfit had told her that she had a direct relation to some important ruler in the past. She asked me if I'd ever delved into my past and if I knew who my people were.
"No, but I do know where we got our start, you carry my family's genealogy to church with you every Sunday."
She looked at me as though I had suddenly sprouted feathers.
"You know, Abraham, Isaac, Jacob...I'm JEWISH!"
She gave it to me that my ancestors were older than her.

(6) J_Payba, November 9, 2011 10:24 PM

Seeking my ancient roots

I always been facinated on my surename, I always wanted to know where my family name came from because it doesn't sound to filipino. I start searching first to the i-net since its the fatest way of having information, then i stumble upon list of sephardic jews where thesame spelling of my surename writen. I also found out that we ave spanish blood line, but still i want to have genetic testing to confirm. Now im trying to find where i can test, wish me luck. =)

Daniel, December 8, 2013 5:36 PM

DNA Test for Jewish Heritage!?!


Although there is no DNA test to determine whether or not you are "Jewish", as that is strictly the purview of the Rabbis, there are three different [genetic] DNA tests that will help you determine if you have Jewish 'heritage'. And thoset DNA tests are, the autosomal (atDNA), mitochondrial (mtDNA), and Y chromosome (yDNA) tests.

Start with the mtDNA test, as that will show you the haplogroup of your mother (-which is of utmost importance). If you match other people who have a preponderance of Jewish DNA, then that is a strong 'indicator' that you have Jewish heritage on your mother's side.

Next, take the atDNA test, as that examines your maternal, and paternal sides, including all grandparents, going back at least five generations.

Last, if you have the funds, test your yDNA, as that will at least indicate whether or not your father belongs to a haplogroup that is typical of men of Jewish descent / heritage.

* Caveat: If there are converts to Judaism on your paternal, and/or maternal lines, then genetic DNA tests will indicate little, if any, Jewish heritage. *

The best company to order these tests from is, Family Tree DNA, located in Houston, Texas. You can find them online.

All the best with your quest,


Daniel, December 9, 2013 3:04 AM

"Jewish DNA" - A Clarification

I expressed myself incorrectly, as the term, Jewish DNA. is a misnomer. This is due to the fact that the father, and mother, of all Jews came from the ancient Mesopotamian city of Ur. And although they are the progenitors of the Nation of Israel, they were not Israelites. Furthermore, whenever converts, e.g., Ruth the Moabitess, have children, their DNA often adds yet another genetic haplotype to B'nei Yisrael. Hence, there is no such thing as, Jewish DNA.

Having said that, if you take the mtDNA test, and most, or nearly all of your matches claim to be Jewish, then that would indicate that your mother shared the same, or nearly the same, haplogroup as women of known Jewish descent.

So, if that occurs, you could research the genealogical records of your [direct] maternal line, i.e., your mother's, mother's, mother, etc., as far back as possible, to see if you can find a women who had a ketuba (marriage agreement), and/or a Get (divorce decree) recorded. If you find one in your mother's direct maternal line, then an Orthodox Beit Din will decide whether or not you have sufficient evidence to satisfy halackhic requirements to establish "Jewishness".

Sorry for any confusion,


Adrienne Kuhn, May 29, 2015 3:51 AM

Ashkenazi mtdna subclade and Jewish cousins seeking 18th century proof for Beit Din

I took the full mitochondrial sequence at FTDNA and emerged as H56a, an Ashkenazi subclade. My 20 coding region matches are Jewish. I took this test because I had several unexpected Jewish relatives at 23andme. I would like to find evidence of past Judaism for a Beit Din. My earliest known female ancestor immigrated from Germany and was born there around 1794. To my knowledge, she was raised Protestant. I can't imagine this trail goes back much farther since I don't have DNA relatives in modern Germany. It sometimes feels like an impossible task, finding such records. If I did, I wonder how I would fare in the court. I am willing and enthusiastic regarding religious education, and I have been to Israel. It sounds a bit odd, but I feel that I was born with a Jewish neshama.

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