Wednesday, August 8, 2012
The Family Finder autosomal DNA test from FamilyTreeDNA serves a two-fold function with regard to genetic genealogy: (1) it measures the changes in the single points in your genetic code (the A, G, C, and Ts) and calculates the relationship to your matches based on the number of markers you share with each one; (2) and it compares your marker values to those represented by population groups in other geographic regions to determine your ethnicity. This second function of the autosomal DNA test has come in handy several times, most recently with my friend Keith, whose data I am helping to interpret.
Shortly after I sent Keith his list of matches he sent me an email asking if his DNA test could tell him if he was Native American Indian. I get this question a LOT – anytime I mention a DNA test to anyone. It seems like everyone wants to prove their Native American Heritage. The answer to Keith’s question is both yes and no. The autosomal DNA test will tell you your ethnicity but it is only an estimation, not an absolute. It varies depending on the sample size ftDNA has collected for that geographic region.
Well all ambiguities aside, I was still able to use ftDNA’s Population Finder tool to pull up a map of Keith’s ethnicity based on his results and matches. Here is a view of his map:
According to ftDNA, Keith has the following ethnicity:
90% Western European (defined as Orcadian)
10% Middle Eastern (defined as Palestinian, Bedouin, Druze, Jewish, Mozabite) – primarily Jewish
Keith was disappointed that he didn’t find any Native American Ancestry. To be honest, I’m not sure what it would say if there was Native American Ancestry! I’m still reading blogs and trying to find people who have tested and whose results have come back as Native American Ancestry.
His report didn’t really tell us much about his ancestry. If we look at a map of the world we can determine that the area on his map that is shaded dark blue and labeled as the “Orcadian” population corresponds to the present day UK (England) and Ireland. The Middle East population corresponds to present day Algeria, Libya, Egypt and the Sudan.
Keith said he didn’t have any Middle Eastern heritage that he knew of. This was the first I had seen of this population showing up in a person’s population finder results. Then it just so happens I was reading Roberta Estes’ blog, DNA-eXplained one morning while eating my breakfast and came across her blog post, “The Dreaded “Middle East” Autosomal Result.” In this post, Roberta explains that the result of Middle East ancestry is sometimes a clue to Native American Ancestry! She reports that she often sees this Middle Eastern admixture in the results of people who are looking for Native American Ancestry. In this post she uses the inhabitants of Hattaras Island as an example of how populations intermarried with persons on the island, mixing very little with non-inhabitants, resulting in very little new DNA being introduced.
Although Keith’s ancestors were not native to Hatteras Island that we know of, his great-grandparents and 2nd great-grandparents were already in the United States following the Revolutionary War. According to Roberta’s calculations, a 10% ethnicity of Middle Eastern should have come from his great-grandparents or 2nd great-grandparents which would have been alive during the 1800s. We do not have all of the names, birth dates and locations of all sets of his first and second great-grandparents though, at this time, so there is still a possibility of Middle Eastern ancestry showing up.
Ginger R Smith, "Genetic Genealogy - What is my Ethnicity" Genealogy by Ginger, posted 08 August 2012 (http://http://genealogybyginger.blogspot.com : accessed [access date]).