I’m a Euromutt. At least, that’s what the “ethnicity estimate” from one of the big DNA testing companies says.
Who Am I?
The company doesn’t actually use the term “Euromutt.” Instead, it estimates with high confidence that 47% of my DNA comes from West Europe, 12% from Scandinavia, 12% from Great Britain, 11% from the Iberian Peninsula, and 7% from Ireland/Scotland/Wales. The remaining estimates come involve “Low Confidence Regions” and suggest that 6% of my DNA might have come from East Europe, 3% from Finland/Northwest Russia, and 2% from Southern Europe.
But I don’t put a whole lot of stock in those numbers, because as the company that tested my DNA explicitly states, “Your DNA never changes, but the science we use to analyze it does. We're always collecting more data, and science is constantly improving, so your estimate may change over time.”
So I could wake up tomorrow and discover, for example, that my DNA is only 44% West European, not 47%. The estimates may change, but my ancestors don’t. And who knows? The day after tomorrow, I might be informed that I have some Native American DNA. Or Nigerian. Or maybe even Polynesian.
Interpreting DNA Tests
Much as we’ve gotten the idea that DNA testing is completely objective, bulls-eye accurate, and utterly infallible (at least on CSI), that’s just not the case. Even the company that performed my DNA test and analysis calls its determination of my geo-genetic heritage an “estimate.” And indeed, that’s all it is.
DNA doesn’t come with microscopic signs that read “East Europe” or “Iberian Peninsula.” Rather, after my DNA was sequenced, it was compared against a database of DNA samples. The comparison method is proprietary, meaning that it varies from company to company. And the databases are always changing as more research is done and as more people get tested.
Right now, genetic databases generally have the most information about European DNA. The wealth of European data allows my DNA testing company to zero in on relatively small areas like “Scandinavia” or “Great Britain” pretty precisely. Contrast that to my company’s map of “Native American” DNA, which encompasses a huge area from Canada’s Northwest Territories to the southern extremities of Argentina. If your long-ago ancestors came from those regions, you may be out of luck if you’re hoping for any kind of specificity.
Why can’t the company confidently zero in on Native American DNA more precisely? Because it doesn’t have enough samples to work from. A database is only as good as the quality and quantity of its data, so if it doesn’t contain a lot of good information about the genetic differences between, say, the Ute and the Innuit, it can’t pinpoint where your ancestors might have lived.
Category Overlap in Ethnicity Estimates
You might have noticed something ambiguous in my ethnicity estimate. With “high confidence,” it was estimated that 12% of my DNA was from “Great Britain” and 7% was from “Ireland/Scotland/Wales.” Of course, as we all learned in third grade geography, Great Britain is an island that encompasses England, Scotland, and Wales. So is that 7% of my Irish/Scottish/Welsh DNA included in the 12% of my “Great Britain” DNA? Apparently not, since then the percentages wouldn’t add up to 100. But then what do these two figures mean?
Genetic mapping is done by identifying clusters of individuals based on their DNA. Some parts of Great Britain, such as Wales and Scotland, have “highly differentiated” DNA, meaning that it’s unique to a comparatively small region. However, much of the rest of Great Britain’s genetic heritage—essentially, the DNA from southern and central England—is not differentiated. So in this case, my test might be interpreted to mean that my DNA is 12% English and 7% Welsh, which isn’t a conflict at all.
What about that estimate that 11% of my DNA is from the Iberian Peninsula (Spain and Portugal)? This was a surprise to me, because while I have family history documenting ancestors from Germany, Sweden, and Wales, I never heard of anyone in my family coming from Spain or Portugal. Consider, though, that there has been extensive commerce between Great Britain and the Iberian Peninsula for more than 500 years. Consider, too, that 24% of the people in Great Britain also have DNA that originally came from the Iberian Peninsula. So perhaps a Portuguese trader and an English shopkeeper’s daughter produced a child who was my ancestor. We are, after all, a migratory species.
Genealogy vs. Ethnicity
You also might have noticed that some of the estimates in my DNA estimate were rather nonspecific. It said that I had a lot of DNA that’s common to “West Europe.” It didn’t say that my genetic ancestors came from France, Belgium, Germany, The Netherlands, Switzerland, Austria, or Luxembourg. Those countries are political creations, not clusters of particular DNA sequences. And like all political creations, the borders of nation-states shift and change. Imagine a woman who is born in Prussia in 1871, brought up in Germany, and dies in Poland in 1949—without ever leaving her hometown. Does that make her Prussian, German, or Polish? She never moved, but the borders did.
This example illustrates the distinction between genealogy and ethnicity. Ethnicity is one’s cultural origin and doesn’t have much to do with DNA. Ethnicity is passed along in traditions, tastes, settlements, religions, art, and languages. Genealogy, as the word implies, has to do with one’s genes, one’s actual line of descent.
We don’t yet have the data or the technical ability that would be needed to trace each of us back to the birth of homo sapiens. If we went back just six generations, we would be looking at 64 ancestors, each of whom contributed only 1.56% of our DNA. Go back ten generations and each of our ancestors would have contributed only about 0.1% of our DNA, which is beyond the limits of present-day DNA testing to identify. But if we could trace our genealogy back 60,000 years, it would lead to Africa.
Are We One People?
Longstanding anthropological research suggests that homo sapiens originated in Africa and began to spread to other continents about 60,000 years ago.
At that time, there may have been as few as 10,000 human being on the entire planet. Today the world’s population stands at 7 billion and has spread to every habitable corner of the globe. But all of us are, as National Geographic says, an African species.
How, then, do we determine ethnicity? Not through DNA testing. DNA only suggests our ancestry for a miniscule portion of the time that human beings have walked the earth. And it can never reveal our ethnicity, despite what DNA companies “estimate.” At best, DNA testing can give us clues about where our ancestors may have lived comparatively recently. Different writers have come up with very different ideas of what “comparatively recently” means, ranging from 200 years ago to 1500 years ago. But even the high end of that range takes in only 2.5% of the time since human beings left Africa.
Testing DNA, Raising Questions
None of this is to say that DNA testing and analysis is foolish or useless. Far from it. They satisfy a basic human curiosity to find out where we came from. They raise tantalizing questions, but don’t provide certainty. So long as you understand the limitations on their ability to trace your ancestors back to a particular place and time, you’ll probably be delighted to receive even a educated guess of where your ancestors were living hundreds of years ago. I know I was. So if you’re interested in getting your DNA tested—and comfortable with taking the possible risks it poses—check out our Top Ten DNA Testing Companies.