Ethnicity estimates are part of every significant DNA testing company’s offerings. What do they mean? Are they even accurate? Can I use them to further my research, or are they just informative? Let’s break it down.
Ethnicity reports are created by DNA testing people from a particular population to make what is known as a reference population. Members of these reference panels are typically people with ancestors who lived in one location over several generations. The DNA of these reference populations is analyzed to determine what genetic makeup is typical of a specific ethnic group. When you take a DNA test, your DNA is compared to the genetic profiles generated by the reference panels. However, no two DNA companies have tested the same people or used the same criterion to create their reference populations. As a result, your estimates will vary depending on which DNA company you consult (*1). Each company specializes in certain ethnicities, as shown by the table below (*2). European results, in particular, vary because populations moved around in that small area over many years, making it more challenging to isolate the DNA of specific groups. Since this is a developing science, ethnicity results are most reliable at a continental level. Additionally, your ethnicity estimates will likely change over time. That’s because companies obtain new data and use improved methodology to create their reference populations and compare them to your DNA (*3).
DNA Company Specialization
I’ve taken an Ancestry DNA test and this is my most recent ethnicity report:
To see how accurate this report was, I compared it to what I know about my ethnic makeup from traditional research. Looking at my tree, I could account for about 78% of my ethnic makeup. (Keep reading for instructions on how to estimate your own ethnical background without DNA testing).
I came up with a lot less Germanic Europe and England & Northwestern Europe at 16% each; likely because of the gaps in my traditionally researched family tree.
15% for Norway seems relatively high. I only have one known Norwegian line through a maternal third great-grandmother, making me only about 3% Norwegian. I possibly inherited more DNA that seems ethnically Norwegian, or the Norwegian reference panel needs refining to yield a more accurate percentage. Another possibility is that I need to research that part of my family to see if more Norwegian is coming from an NPE (not parent expected) in my tree.
When I calculated my well-documented Swedish and Danish ancestry, I determined that I’m 12.5% Swedish and 10.94% Danish, which yields 23.44%. That’s over double Ancestry’s 10%. Perhaps some of my Swedish and Danish DNA is being misattributed as Norwegian. When I subtracted 3.13% from Ancestry’s 15% Norwegian, I got 11.87%. Adding that 11.87% to the 10% Swedish and Danish adds up to 21.87%, much closer to the percentage I know from traditional research.
The percentages for Wales, Scotland, and Ireland match pretty closely.
I don’t know where the 1% Baltics comes from, but I suspect my maternal German ancestors, who may have lived further east than present-day Germany since they came to America pre-German unification.
If you want to estimate your ethnical background (without DNA testing) like I did, here’s how you can.
Create a tree diagram using diagrams.net or another application of your choice and build each line until you reach an ancestor that is 100% of an identifiable ethnicity. (In my case, a few are unknown, so list that).
Label the ancestors' ethnicity and highlight them in a color that makes them easy to see.
Half the percentage for every generation between you and the ancestor to get what percentage of ethnicity you inherited from them.
Combine percentages for ancestors of the same ethnicity.
Add all percentages together to determine what coverage you have.
Earlier this year, Ancestry added another feature to its ethnicity reports called Ethnicity Inheritance. This update uses a technology called SideView to analyze segments of DNA you share with your matches to determine which parts of your ethnicity came from which parent (*4). This could be powerful for people who do not know the identities of one or both of their parents. But again, we must ask, how accurate and reliable is it? Let’s put it to the test.
Here is a screenshot of my Ethnicity Inheritance chart. It’s important to note that typically it labels your parents as Parent 1 and Parent 2 rather than Maternal and Paternal like mine does. That is because both of my parents have also taken Ancestry DNA tests.
Germanic European
Maternal 29% - this is consistent with what I know about my maternal family
England & Northwestern Europe
Maternal 4% - I hypothesize this comes from a maternal second great-grandfather I’m currently researching who may have been part English rather than German as he claimed during his life.
Paternal 20% - this is consistent with what I know about my paternal family
Norway
Maternal 12% - My one documented Norwegian line is maternal. The amount is still very high as previously discussed.
Paternal 3% - I do not know where this comes from; it could be misattributed to Swedish or Danish.
Sweden & Denmark
Paternal 10% - while my maternal side does have Swedish and Danish roots, this is not entirely accurate. I have a documented Danish line on my maternal side, so some of this percentage should have been attributed to my maternal side.
Wales
Paternal 8% - this is consistent with what I know about my paternal family
Scotland
Paternal 8% - this is inaccurate because I have Scottish lines on my maternal and paternal sides
Ireland
Maternal 4% - Again, I hypothesize this comes from my elusive second great-grandfather of dubious origins.
Paternal 1% - I know of at least one paternal Irish ancestor.
Baltics
Maternal 1% - this is consistent with my hypothesis that some of my maternal German ancestors may have lived further east than in present-day Germany
Based on this exercise, it seems Ethnicity Inheritance has good potential but needs refining, so don't be surprised if your ethnicity estimates shift in the future.
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Footnotes/References:
Jayne Ekins, “DNA Ethnicity Estimation: Reference Panels,” Your DNA Guide, 9 December 2019, (https://www.yourdnaguide.com/ydgblog/2019/6/6/dna-ethnicity-estimation-reference-panels : accessed 22 Sep 2022).
Diahan Southard, “Premium: DNA Q&A: All About Ethnicity Estimates,” Family Tree Magazine, 3 May 2021, (https://www.familytreemagazine.com/dna/dna-qa-best-ethnicity-estimates/ : accessed 2 June 2021).
Jeffery Adrion et al., “Ethnicity Estimate 2022 White Paper,” Ancestry, (https://www.ancestrycdn.com/support/us/2022/08/ethnicity2022whitepaper.pdf : accessed 22 Sep 2022).
“How SideView™ Technology Splits Your DNA Results by Parent,” Ancestry (https://support.ancestry.com/s/article/SideView-Technology?language=en_US : accessed 13 Apr 2022).
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