In the past year, I’ve uploaded my 23andme autosomal raw data to all Gedmatch admixture calculators, DNA Tribes and Family Tree DNA (where I have mtDNA results on file). I sought out guidance on the accuracy of the tools that I’d used, and suggestions for better products.
I wanted scientific precision, but have settled for impressionistic results that vary from tool to tool but basically reach a similar conclusion: my ancestry is 98% European and 2% Something Else.
At 23andme, that Something Else is Unidentified.
At FTDNA’s “My Origins,” that 2% of my ancestry came from North African and Asia Minor.
At any of the Gedmatch admixture calculators, that 2% or more is +/- some combination of Amerindian and Sub-Saharan African, usually with a higher portion of non-European identified as African rather than Native.
I am, it seems, a geno-reflection of findings recently published in The American Journal of Human Genetics : “The Genetic Ancestry ofAfrican Americans, Latinos, and European Americans across the United States.”
Using genetic information obtained from 23andme customers, Katarzyna Bryc, et. al concluded “the frequency of European American individuals who carry African ancestry varies strongly by state and region of the US (Figure 3A). We estimate that a substantial fraction, at least 1.4%, of self-reported European Americans in the US carry at least 2% African ancestry. Using a less conservative threshold, approximately 3.5% of European Americans have 1% or more African ancestry (Figure S8). Individuals with African ancestry are found at much higher frequencies in states in the South than in other parts of the US: about 5% of self-reported European Americans living in South Carolina and Louisiana have at least 2% African ancestry.”
Their findings also seem to illuminate my lower percentages of Native to African ancestry: “Fitting a model of European and Native American admixture followed later by African admixture, we find the best fit with initial Native American and European admixture about 12 generations ago and subsequent African gene flow about 4 generations ago.”
My Native ancestry, which probably entered my “gene flow” in Eastern North Carolina twice as long ago as my African ancestry, has anecdotal roots. Numerous distant relatives have repeated the story that my great, great grandmother, Mary Ann Armstrong Parisher, had Native ancestry, yet no one seems to know its origins. No one has ever offered up any anecdotal suggestions of African ancestry, even though it is likely that it would have been introduced more recently. Lacking anything but my own genotyping to work with, I suspect that Mary Ann Armstrong might be the source of both my African and Native ancestry.
I accept that I may very well never know the stories that explain my 2 percent --- although I would really, really like to know them. For now, I’ll have to make do with the knowledge that like many predominantly European Americans with roots in the South that go back more than 400 years, I am a product of intimate knowledge that has been forgotten or hidden for generations, only to surface through genetic testing -- my most intimate level of body knowledge.
That going down home -- delving deep into an invisible storied past -- seems so scientifically possible, yet not. I've met other people on the same journey, and suspect that in 2015, the journey itself will be what's important.