November 2007

Jewish Genealogy and the Current State of DNA Research

Our speaker introduced himself as 12 23 14 10 14 17 11 17 12 13 11 29, the twelve markers of his Y chromosome. Bennett Greenspan is an entrepreneur and a Genealogist since his teen years. This passion for genealogy and his entrepreneurial spirit led to the creation of Family Tree DNA in 1999. 

When the ancestral paper trail leads to a dead end, Family Tree DNA to the rescue. Although DNA testing cannot create a family tree or define familial relationships, this testing can verify that family relationships exist and provide probabilities of how many generations back where the two people tested had a common ancestor, but cannot tell you HOW you are related. Also, it is important to know that DNA testing can only determine relationships for your all male ancestral lineage (father’s father’s father … for men) and your all female ancestral lineage (mother’s mother’s mother … for both men and women). Or, put another way, the use of DNA testing can only verify relationships of 2 of 4 grandparents, 2 of 8 great grandparents, 2 of 16 great great grandparents, etc. 

Each of us inherits 46 chromosomes from our parents – 23 from our father and 23 from our mother. Twenty-two pairs are autosomal (non-sex chromosomes) and two – X and Y – determine sex (XY in men and XX in women). The Y chromosome passes from father to son with virtually no change. Mitochondrial DNA (mtDNA) is passed down from females to both sons and daughters, but sons do not pass down their mother's mtDNA to their children.

The first DNA study was the Cohanim study that identified that 50% of Ashkenazi men who identified themselves as a Cohen had the same DNA signature and 60% of Sephardic men identified as Cohen had the same DNA signature. For more information, see the list of relevant webpages at the end of this article. 

Also in the headlines was the discovery through DNA of a relationship between Sally Hemmings, a slave at Monticello, and Thomas Jefferson or a male relative of Jefferson’s. For more information, see the list of relevant webpages at the end of this article. 

Bennett also talked about events in the history of the Jewish people that may have determined a person’s Haplogroup -- A genetic population group associated with early human migrations and which can today be associated with a geographic region. These events were migration, such as the banishment of Jews from Eretz Yisroel by the Romans, migration to Southern Germany and the Iberian Peninsula, migration to Poland and Lithuania; conversion, such as Khazars and forced conversions in Spain and Portugal; and so-called bottleneck events that reduced populations such as the Crusades, the Black Plague, and the Chmielnicki pogroms in Ukraine. 

Family Tree DNA has many group projects – surname, geographical, SIG (Special Interest Group), and Heritage projects. See this list of projects at the JewishGen website at http://www.jewishgen.org/DNA/.

If you are interested in identity and DNA of our people, Bennett recommended a newly published book, Abraham's Children: Race, Identity and the DNA of the Chosen People, written by Jon Entine. Read more about the book at http://tracingthetribe.blogspot.com/2007/10/abrahams-children-and-jon-entine.html.

If you are interested in DNA testing, Family Tree DNA offers JGSGP a special group rate. An order form and more explanation is provided.