Genetic genealogy: a new way of studying family history


Scraping some cheek cells into a test tube can uncover previously unknown apparent distant relatives, but unless these "exact matches" that imply a shared ancestor can also be documented in other ways, such as through family tree links or at least shared surnames or hometowns, the results can raise more questions than they answer.


By Martin Fischer


After decades of conducting genealogical research in the traditional manner, the opportunity to try something new can be appealing, particularly when the technology of genetic genealogy offers the possibility of breaking through a family history research roadblock. In my case, one of the biggest obstacles I have encountered has been the inability to pinpoint the town of origin of my Fischer ancestors.


We know from 19th Century U.S. census and citizenship records that my great-grandfather Morris L. Fischer was born about 1839 in Germany. But in order to pursue further research into his forebears, we need to know his original hometown in the old country. He is believed to have immigrated to the United States by 1865, when the German Empire included a wide swath of central Europe extending from present-day Germany through Lithuania and part of Poland.


Since investing in a Y-DNA test through FamilyTreeDNA, I have been notified of more than 30 men (at the time this article was written, but by September 2011, more than 270 12-marker matches) who are "exact matches" to my direct patrilineal ancestors. Unfortunately, none of these men share my surname, so the likelihood of documenting a family tree link is unlikely. According to the FamilyTreeDNA Web site, matches of this 12-marker Y-DNA test who don't have the same surname are "probably NOT recently related. When we use the term recently related, we are talking about a time frame within the last 1,000 years or 40 generations, a time depth that accommodates the earliest known use of surnames." In other words, my Y-DNA exact matches and I are probably related, but our shared ancestors most likely lived before they adopted surnames.


Despite this shortcoming, I thought it still might be of some value to contact my Y-DNA matches, most of whom have allowed FamilyTreeDNA to relay their e-mail addresses to all their matches. So I recently sent the following e-mail to my genetic matches:


"According to FamilyTreeDNA, we share a direct patrilineal ancestor because our Y-DNA tests matched. But since we have different surnames, it is unlikely that our common male ancestor could ever be identified because he probably lived before our surnames were adopted.

"However, I think there might be a way for you to help me get past a roadblock that I have encountered in my genealogical research. The earliest known members of my direct patrilineal line were my great-grandfather Morris L. Fischer and his father, Chaim ha-Kohane. Unfortunately, I don't know their town or shtetl of origin. All I know is that 19th Century records indicate they were from Germany, but on today's map that could include parts of Poland, Lithuania or Belarus as well.

"So I am writing to all 32 of my Y-DNA matches whose e-mail addresses I have to ask if they can tell me where their direct patrilineal line originated in Europe. The more specific your response, the better. 

"If I can map a cluster of locations from most of my Y-DNA matches, this might enable me to home in on the Fischers' origins and help me to focus my future research."

I received 13 e-mail responses from my genetic cousins, which has enabled me to plot on a map nine  documented and one hypothetical town of origin. Interestingly, the map shows two apparent clusters for my Y-DNA cousins' patrilineal ancestors: One is in the current nation of Lithuania, which in the 19th Century was part of Prussia, a German territory. The other is in the current region where the borders of Poland, Ukraine and Slovakia meet. This area was known in the 19th Century as Galicia, part of the Austro-Hungarian Empire.

Our earliest direct patrilineal ancestors may have fled the consequences of 11th Century internecine Arab turmoil in Tunisia for Spain and then fled Spain in the wake of the 1492 Inquisition by land into central and eastern Europe and by sea to Rhodes. (Base map from Cartographic Research Lab, University of Alabama)

The following list summarizes the results of my informal survey of our genetic Y-DNA cousins, with surname listed first in italic, earliest town of origin listed second (using current spellings of place names from Behrendt, Krotoszyn, Poland; Benveniste, Rhodes, Greece; Carvin, Busk, Ukraine; David, Kolomyya, Ukraine; Gottdiener, Malá Tŕňa, Slovakia; Kaplan, Kaunas, Lithuania; Krastman, Pandėlys, Lithuania; Miller, Tytuvėnai and Kelmė, Lithuania; and Tabak, Krasnobród, Poland.

The clustering of many of our ancestors in two distinct geographic regions is a reflection of the dispersal of Jews throughout the world. At some point in the distant past most of our ancestors' paths diverged, one to the north into Lithuania, the other to the east into Galicia.

Another way of looking at our distribution throughout Europe is found on the "recent ethnic origins," or REO, table of our Y-DNA matches and one-step mutations shown on the FamilyTreeDNA Web site.

This "REO" data is less precise geographically than the self-reported towns of origins that I received in response to my e-mail query, but it is based on a substantially larger number of responses—70 in total, 49 of whom specified the nation that was their patrilineal line's place of origin.

Our exact direct patrilineal matches and 1-step mutations were widely distributed throughout eastern and central Europe. Not shown on the chart are 8.6% who specified other nations of origin and 30.0% with unknown origins.

The limiting factor in evaluating the reported country of origin is the lack of historical perspective: The term "recent" is a matter of interpretation, and as borders have shifted over time, the reliability of the self-reported nation of origin may be questionable for an unknown number of us. For example, I specified that my Fischer line came from Germany because of 19th Century documents that mentioned the Empire of Germany, but this could include Prussia, which today is located in Poland, Lithuania and part of Russia.

While with this data we lose the geographic clustering that we found when plotting the map of towns of origin, we gain perspective on how widespread most of our genetic cousins have been distributed throughout central and eastern Europe.

A key historical distinction that emerges from our shared genetic heritage is the fact that most of us consider ourselves Ashkenazic Jews, but one of us, Mr. Benveniste, is a Sephardic Jew. (Since researching this article, another likely Sephardic has been added.) This fact is quite significant because it implies that our earliest shared direct patrilineal ancestor might have lived sometime before the division between Ashkenazim and Sephardim occurred.

The first Ashkenazim lived in the 10th and 11th Centuries in the Rhine River Valley of what is today northern France and western Germany. Therefore, it could be inferred that our shared ancestor lived no later than the 11th Century and may have lived prior to the 10th Centurybefore those who became Ashkenazim and those who became Sephardim took their separate paths geographically, culturally and religiously.

But there is another possibility that could have created the same anomaly of having both Ashkenazim and Sephardim on the same direct patrilineal line: Immigration from Sephardic lands into Ashkenazic territories may have been followed by assimilation into the latter society. Joan Hartman, who has done the family history research on Mr. Gottdiener's family, wrote of our Y-DNA cousins' families in her e-mail to me:

"Tales passed down by many of these families have individuals migrating to eastern Europe from Portugal and Spain in the late 15th Century or from their refuge in Turkey in the 16th Century.  Since Spain had the largest population of Jews in the world in the 15th Century, and they all had to go somewhere, it makes quite a bit of sense to me that many of our ancestors in eastern Europe came there from Spain.  My suspicion is that the earliest closest common ancestor we might have had lived in Spain, and that his descendants ended up in random places in Eastern Europe and in the Middle East following the Inquisition." 

Mr. Benveniste's family has been traced to 12th Century Barcelona, Spain. After fleeing the Inquisition in Spain, they lived in the same house on the Island of Rhodes in Greece, just off the Turkish coast, for 400 years. (For details on his family history see his Web site at:

Similarly, one of our ostensibly Ashkenazic Y-DNA cousins has a hypothetical, but credible, historical link to another Sephardic land: Tunisia. Mr. Carvin, whose original family name was Karawan, has written:

"According to research I conducted at the Museum of the Diaspora in Tel Aviv, the name Karawan is attributed to a family of rabbis who ran a talmudic college in the Tunisian city of Kairouan back in the 11th Century. At the time, there was a dynastic power struggle between Arab clans with connections to Baghdad and Morocco, one of which was more tolerant of the local Jewish population. When the other clan's power increased, many Kairouani Jews left north Africa for Spain, well before the beginning of the Inquisition. So it's possible that my ancestors fled Tunisia, settled in Spain, then worked their way east into Galicia as the various western European kingdoms had their periods of Jewish persecution."

Despite our geographic dispersal and our Ashkenazic-Sephardic differences, many of our Y-DNA cousins share a crucial genetic marker that makes us unique as a group: the Cohanim gene, known as the Cohen Modal Haplotype.

The Cohanim were members of the tribe of Levi who served as priests in the Temple in Jerusalem starting 2,000 to 3,000 years ago. (Their assistants in the Temple were non-Cohane members of the Levites. All non-Levites were designated  Israelites.) The Cohane status was carried from generation to generation through the patrilineal line that originated with Aaron, Moses' brother. Both Ashkenazim and Sephardim can be Cohanim. Genetic studies have shown that men whose families have a tradition of them being Cohanes carry the Cohen Modal Haplotype in significantly greater percentages than do other Levites and Israelites.

In my case, I know that I am a Cohane because my great-grandfather Morris Fischer's tombstone identifies him as Reb Moshe ben Chaim ha-Cohane: Moses, son of Chaim the Cohane.

According to the FamilyTreeDNA table of our exact Y-DNA matches' recent ethnic origins, 27% of us have the Cohen Modal Haplotype (18.2% of our one-step mutations have it; 22.2% of our two-step mutations have it). In addition, among the 34 exact Y-DNA matches for whom we know the surnames, 10 of them (28.6%) have surnames (Cohen, Conn, Katz, Katzman) that are traditionally Cohanic. These figures are significant greater than the 10% or less of the general Jewish population who reportedly have the Cohen Modal Haplotype, according to genetic researchers.

Returning to my original question, my goal of identifying my Fischer ancestors' place of origin has not been achieved as a result of these contacts with our Y-DNA matches. Nevertheless, if I consider the two east European clusters—Lithuania and Galicia—the former is more likely as my ancestors' homeland because Lithuania is located in the former East Prussia, a German territory.

Related Web sites:

Introduction to genetic genealogy

From time to time, I have responded to queries from subscribers to various JewishGen listserves asking about the basics of genetic genealogy. They may have already read the frequently asked questions about genetic genealogy posted on various Web sites, but still don't understand it.


By Martin Fischer

I am no geneticist, but I have had my Y-DNA and Mt-DNA tested through FamilyTreeDNA.

As I understand it, according to genetic theory, a man's Y-DNA was shared by all of his direct patrilineal ancestors (father's father's father, etc.), and his Mt-DNA was shared by all of his direct matrilineal ancestors (mother's mother's mother, etc.).

Men can have both tests done. Women can have only their Mt-DNA tested because they don't have a Y chromosome.

In a standard ancestral family tree, your own Mt-DNA and Y-DNA tests will generally only trace along the exterior lines of the tree and will provide no genetic information about those ancestors shown on interior lines of the tree. (However, all siblings of either sex within a given nuclear family should share the same Mt-DNA if they have the same mother, and all male siblings within a given nuclear family should share the same Y-DNA if they have the same father.)

For many years, if you were interested in gaining genetic information about other ancestral lines that are diagrammed on the interior of your ancestral tree, you would have needed to find a relative who is on one of these other lines to have them take the Y-DNA or Mt-DNA tests. Today, a third test is available to gain genetic information about one's entire ancestral family tree. This autosomal test is called the Family Finder test by FamilyTreeDNA.

One problem with the autosomal test is its all-encompassing nature that makes it hard to determine just how you may be linked to your genetic matches. To at least potentially enhance your interpretation of this test, it is still valuable to have known relatives take the Y-DNA and Mt-DNA tests.

Here is an example: My father is deceased. I am a male and have had my Y-DNA tested, and because my father was on my direct patrilineal line, I have no interest in finding another relative to test his Y-DNA. I have no need to have my brother's Y-DNA tested because it should be identical to mine.

However, I am interested in having my father's sister (or my father's sister's daughter) tested for their Mt-DNA. My Mt-DNA derives from my mother, but my father's and his sister's Mt-DNA derives from their mother, who was my paternal grandmother. Results of that test would trace along that grandmother's direct matrilineal line.

Finding another relative to test needs to be carefully considered. Would the person be open to such a test? Would you pay for it or would they, or would you share the cost? Most important, is the person related to you in such a way that it could potentially lead to previously unknown blood relatives of yours?

Another example: I have a male second cousin who is very close as a friend, but not very close on my family tree. We share a known common ancestral married couple who lived in the early 19th Century.

But I have no personal interest in having either his Y-DNA or Mt-DNA tested because it would provide me with no information about my own genetic ancestors. Here is why: His mother was not related to me in any way, so the Mt-DNA he inherited from her is of no value to me. His father was descended from our common ancestors through his father's mother; his direct patrilineal line through his father's father's father, etc., does not connect to our common male ancestor, which means that my second cousin's Y-DNA has no link to mine.

I know this sounds very complicated, but when you have your own family tree in front of you available for study, then you should be able to figure out which other relatives should be tested.

A careful consideration of a relative's own ancestry should be done before deciding whether this relative's genetic information would contribute to knowledge of your own genetic ancestry.

Subsequent to writing the above paragraphs about my early experiences with and speculation on my Y-DNA test, the total of my Y-DNA "exact match cousins" has increased to 89 men (as of April 2006), almost all of whom have a known Ashkenazi background. But three of the 89 are Sephardic, which suggests that the shared ancestor they have with the rest of us probably lived before the emergence of the Sephardic-Ashkenazi divide. Also, one of the Ashkenazim has a surname derived from the name of a town in Tunisia, so he suspects his ancestors were Sephardic and immigrated to eastern Europe. Interestingly, one of our Y-DNA matches has no knowledge at all of his father, because his father was an anonymous semen donor. While we 89 genetic cousins have not been able to establish any known genealogical links, we have had numerous fascinating e-mail discussions.

My Mt-DNA matches now (as of April 2006) total 47, both men and women. After upgrading from the 12-marker Mt-DNA test to the 25-marker test, eight of the 47 have been separately listed as high-resolution matches, meaning that our most recent shared ancestor lived much more recently than that of the 39 others who are only low-resolution matches.

Most of my Mt-DNA matches have known Jewish ancestors from eastern Europe, but we were all stunned by one of the more recent additions to the high-resolution list of matches whose only known ancestry is Irish Catholic! Needless to say, that led to some interesting speculative e-mail discussions about immigration patterns.

Ancient immigration patterns are believed to be reflected in Haplogroups, which are identifiable as a result of these genetic tests. Haplogroups are genetic markers that can define genetic groups. For example, my Y-DNA has been defined as part of Haplogroup J1, which, according to FamilyTreeDNA, "is found at highest frequencies in Middle Eastern and north African populations where it most likely evolved. This marker has been carried by Middle Eastern traders into Europe, central Asia, India, and Pakistan."

My Mt-DNA Haplogroup is K1a9, a subgroup of Haplogroup K, which is believed to have originated in the area between the Black and Caspian Seas and spread northward and westward into much of Europe. Haplogroup K is found throughout Europe today and is not specifically identified as Jewish or Middle Eastern, but most of my Mt-DNA matches have Jewish ancestry.

If you have your genetic testing done by FamilyTreeDNA, the best way to start with a Y-DNA test is through one of their surname projects. You can search their list of existing surname projects to see if one with your surname has already been started. If it has not, then you can easily start one. Once your tests have been completed, FamilyTreeDNA e-mails you a link (based on your kit number and a password they provide) to your own personal Web page that lists the names of your matches and their e-mail addresses.

If you yourself take the Mt-DNA test, you will find genetic matches to your direct maternal line (mother's mother's mother, etc.)

If your father's brother's son takes the Y-DNA test, you will find genetic matches to your (and his) direct paternal line (father's father's father, etc.).

There is no requirement for you to publish your cousin's name; however, most people do list the name of the person who has been tested. The only people who will see his name are those who are his genetic matches. (Also, as a general rule it may be useful to also post on your results page the ancestral surnames and places of origin of your direct ancestors. This can help with determining possible family tree links to your genetic matches, because, if you are lucky, they may share your surnames.)

The third genetic test that you yourself should consider taking, if you use Family Tree DNA, is their Family Finder test. That test will find genetic matches for, at least potential, your entire ancestry, including ancestors who were not on your direct paternal or maternal lines. Having all three tests helps understand how you might be related to your genetic matches because many of the same people who match you on Y-DNA and Mt-DNA will also pop up as matches on the Family Finder. For the rest--that is those who are on your Family Finder list but not on your Y-DNA or Mt-DNA lists--you will know that their relationship to you is not through your direct maternal or paternal lines, but rather from the "interior" parts of your family tree.

Assuming that you will use Family Tree DNA, after your test and your cousin's test are completed, each of you will have a private web page on their website showing your genetic matches, all of whom will be listed by name and email, so that you may contact them to exchange family history information to try to figure out your relationship. In order to log into these private pages, you will need the genetic test kit number and a password created by Family Tree DNA, which they will send you by email. Make sure you make a note of these numbers so that you don't lose the ability to access them. If your cousin orders the test himself, make sure he is willing to share these numbers with you so you can see the results. If you order his test for him, that won't be a problem.

One important tip: I highly recommend that, if you can afford it, you order both your Mt-DNA test and Family Finder test at the same time. That way, you will receive just one test kit for both tests, and you are guaranteed that both tests will be under the same kit number and password. (Your cousin's test will have to be under a different kit number and password because he is a different person.) If you can only order one test at a time, then you should wait until you get some of the results posted to your web page from the first test and then be sure to order the other test through your personal page while you are logged into that page. That way, your second test should be under the same kit number and password.

For more information, view the tutorials and videos on the right side of this page:

I hope this helps with your understanding of genetic genealogy. Good luck with your research.



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Experienced amateur genealogist Martin Fischer is available to conduct freelance family history projects including searching online databases, creating family trees, editing memoirs and developing genealogical Web sites. For more information, go to, click on find a freelancer, and type Martin Fischer in the search box, or go to, click on search by name, and type Fischer and Martin in the search boxes.

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