Monday, July 29, 2013

75% Eastern European DNA? Sounds about right to me

I am 99.9% European. I would have guessed that, even if I had never spit into tiny vials for autosomal DNA analysis. Test results from 23andMe confirmed it, though, and took me a step further with its website's Ancestry Composition feature, presenting several different scenarios of what that 99.9% signifies.

Ancestry Composition basically enables you to consider your own DNA heritage in relation to the world's geographic/ethnic populations, which 23andMe has assigned to 22 different groupings. The data "includes DNA you received from all of your ancestors, on both sides of your family. The results reflect where your ancestors lived 500 years ago, before ocean-crossing ships and airplanes came on the scene," the website says.

The primary element is a table that tallies up the percentages of the various world populations reflected in your DNA. A resolution option allows you to see those percentages in three different breakdowns. Here are mine:

Global resolution: 99.9% European + 0.1%miscellaneous = 100% Barbara
Regional resolution: that 99.9% more specifically signifies 75.5% Eastern European, 4.2% Northern European, 0.2% Ashkenazi, 0.2% Southern European, and 19.8% nonspecific European
Subregional resolution: the 0.2% Southern European is more exactly described as representing the Iberian, Italian, and Balkan peninsulas and Sardinia

How does 23andMe define these categories? Eastern Europe encompasses Ukraine, Russia, Poland, and Hungary, and is "bordered on the east by the Ural Mountains." Northern Europe extends "as far west as Ireland, as far north as Norway, as far east as Finland, and as far south as France."

It is unclear to me where Lithuania and Belarus fit into the mix. As one of the Baltic countries, I'm guessing Lithuania falls into the Northern European classification. But what about Belarus? It is bordered by both Slavic countries (Poland, Ukraine, and Russia) and Baltic (Lithuania and Latvia). The population samples cited with these classifications do not include Belarus.

The regional resolution resonates with me. The 75.5% Eastern European DNA makes sense, in terms of my paper-trail genealogical research. Since the 1790s at least, my ancestors are documented as Polish Roman Catholics. I'm comfortable basically attributing the 24% of Northern and nonspecific European DNA to my maternal grandmother's H27 mtDNA, my paternal grandmother's mother's T2b mtDNA, and my paternal grandfather's mystery-man father's unknown but very likely Lithuanian roots. If this doesn't seem completely logical or mathematically accurate, I'm okay with that.

The 0.2% Southern European DNA holds little interest for me. If a stray Sardinian ever shows up in one of my family's marriage records, I will rethink this.

The best-fitting estimate

Another approach to examining the population percentages is via three different estimates: conservative, standard, or speculative.

Personally, I don't feel a need to spend much time mulling the conservative option, which labels 56.5% of my DNA as Eastern European and 42% as nonspecific European with a smattering of other populations contributing 1.5%. All four of my grandparents came from the same small geographic area, an arc that sweeps across western Belarus up into southern Lithuania. I have done reasonably extensive genealogical research on their ancestors—or at least 7/8 of them, my paternal grandfather's paternal line being that one brick wall. And judging from that line's Y-DNA test results, even that great-grandfather fits comfortably into the ethnic populations of the Grodno-Lida-Vilnius region (probably closest to Vilnius).

The standard estimate mirrors the regional resolution detailed above.

The speculative estimate considers my DNA as 87.1% Eastern and Northern European; 1.3% British and Irish (ah, could that account for my love of Celtic music?), 1.2% French and German: 6.1% nonspecific Northern European; and 4.2% a mix of Southern European, Ashkenazi, and general nonspecific European. It is intriguing, and it seems possible, but I have no records to document such fine distinctions, so I'll stick with the standard estimate.

The graphic here displays my standard estimate/regional resolution autosomal DNA analysis, indicating my ancestry is at least 75% Eastern European. It also highlights one aspect of the 23andMe website that I particularly like: it has a visually appealing, colorful, user-friendly design that is accessible even to a nonscientist like me.

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