In 2006, Ancestry.com began offering direct-to-consumer DNA tests. Since then, the company has analyzed the genetic code of over 10 million participants. Over the years, Ancestry has been expanding and refining its reference population samples to improve clients’ heritage percentage reports. On September 12, 2018, the company announced the rollout of new enhanced ethnicity estimates. Per the company’s blog,
Ancestry will deliver ethnicity estimates with increased precision to its customers, through a new algorithm that analyzes longer segments of genetic information, marking an important evolution in the way we interpret DNA data. Having built and expanded our DNA reference panel, we have a better understanding of genetic signatures globally, can break down geographic ethnicity estimates with greater specificity and give you a more detailed picture of your origins.1
What does this mean to the average consumer?
Presumably, Ancestry’s heritage percentage reports will now be more accurate than previous versions. Family historians with cited and sourced pedigrees should see a genetic mix that better matches the paper trail left by their ancestors. Ignoring non-paternal events (NPEs), such as secret adoption and infidelity, users should find the new results satisfactory if not impressive.
Browsing the Ancestry message boards or any of the numerous DNA groups on Facebook reveals mixed feelings among users about the new estimates. Some customers argue the new data is wrong, while others have commented it’s spot-on and verifies their historical findings.
One of the common misconceptions about heritage estimates is that populations can be easily sorted into groups corresponding with modern national borders. With the exception of isolated tribes like the Andaman Islanders, who’ve remained in the same geographic location for over 55,000 years, most ethnic groups are too genetically mixed to provide pure representative samples of their native countries.2 Centuries of European migration and/or intermarriage with people from other regions limits the accuracy of reference samples.
More times than I can recall, I’ve seen some variation of the following complaint posted on a message board,
“I thought I was German, but my DNA test results just say western Europe.”
Germany as a country didn’t exist until 1871, (though some might argue Germany emerged in 1866, with the formation of the North German Federation) and the inhabitants of western Europe had been traveling by land and sea since humans first inhabited the region nearly 45,000 years ago.3
The Germans, in their various changes of territory, inevitably intermingled with other peoples. In the south and west they overran Celtic peoples … Similarly, in occupying the Slavic lands to the east, Germans seem to have taken over and reorganized the Slavs along with their established framework of rural and urban settlements…4
For more information on this topic, refer to my article about central Europe’s changing borders.
Y-DNA (paternal-line) and mtDNA (maternal-line) DNA testing can offer insights on ancient ancestors from thousands of years ago. However, AncestryDNA only offers autosomal testing.
In theory, Autosomal DNA tests can assess a person’s heritage as far back as 500 years.
In practice, an AncestryDNA test (and similar tests offered by 23andme, FamilyTreeDNA, and others) should reasonably estimate the birthplace of someone’s 5th to 6th great-grandparents (going back 250-300+ years). I compared my own verified DNA tree* and paper trail to the new versus old heritage mixtures and I’m happy to report the new estimates are indeed more accurate.
*In this context, a verified DNA tree contains proven ancestors. These ancestors are proven by identifying several 3rd-7th cousin matches who all share the same ancestor or ancestral pair. There must also be enough documentation to verify each of those matches is truly a direct-line descendant of said ancestor(s).
Below are my Ancestry heritage predictions, before and after the new estimates.
To compare these estimates to my verified tree, I noted the birthplaces of all of my 4th great-grandparents. These 64 data points allowed me to create a small spreadsheet of my own reference values. I haven’t yet been able to identify all of of my distant Polish ancestors, so I’ve marked their birthplaces as “region unknown.”
Ancestry’s old and new estimates use different boundaries for parts of Europe. Below is a chart with the birthplaces listed next to their associated regions, per Ancestry. A few of these places “moved” with the implementation of the new algorithms.
The parts of Austria and Hungary where I’ve traced my ancestors back to the early 1700s were previously considered Europe West and Europe South. Now, all of Hungary is grouped with Eastern Europe and Russia. Below, a larger image of the previous estimate map.
The 9% Scandinavian had me puzzled for some time, as well as the 7% Europe South. The rest of the numbers didn’t quite add up either.
The new estimates include fewer locations than the prior estimates, but the percentages and regions are much more accurate.
Also worth noting, the orange area is what Ancestry calls a migration region. Clicking on the map opens a text box that says
You and 1,000+ of your DNA matches, along with 426,987 other AncestryDNA members, are all genetically linked to this region through shared ancestry.
I think that’s pretty neat.
But it gets better.
By taking my 64 4th great-grandparents’ places of birth and sorting the locations in accordance with Ancestry’s new regions, I ended up with 26 born in Eastern Europe & Russia (though technically most of these places are in central Europe), 14 in Germanic Europe, and 16 in England, Wales & NW Europe.
That leaves me with 8 great-great-great-great grandparents who died in Poland, but their places of birth have been a mystery. Luckily, there’s a giant clue in Ancestry’s new estimates.
Approximately 12.5% of my distant ethnicity is unknown. Ancestry suggests I have 16% Baltic States DNA, which also overlaps a large section of the aforementioned migration region. With 1000+ shared matches from this area, it’s a good bet my Polish forebears were ethnically Estonian, Latvian, or Lithuanian.
This may not seem like a groundbreaking discovery, but it can be an excellent tool for finding unknown family. Some adoptees begin their search with nothing more than a heritage breakdown. If, for example, I was looking for a biological parent of central or eastern European descent, this Baltic States discovery would help get me started. Sure, it’s still a long journey, but it helps if you’re pointed in the right direction.
Thanks to Ancestry’s new estimates, I can finally stop searching my matches for Swedes.
- Ball, Dr. Catherine. “Ancestry Unveils More Detailed and Precise Ethnicity Estimates Than Ever Before.” Ancestry.com, 12 Sep 2018, https://blogs.ancestry.com/ancestry/2018/09/12/ancestry-unveils-more-detailed-precise-ethnicity-estimates/