Unless you are paying close attention to the world of commercial DNA testing, you may miss periodic announcements of updates pertaining to possible changes to your ethnicity estimate. You may have initially been told you are a certain percentage of one culture or another only to log in later to find that has been adjusted slightly (or significantly) for some.
As an example, my initial ethnicity results at AncestryDNA, prior to September 2018, looked something like this:
In September of 2018, AncestryDNA announced they had increased the number of reference samples being used to estimate your ethnicity to 16,000 which is significantly higher than the 3,000 used previously. As a result, my new ethnicity estimate now looks like this:
As you can see, it’s not a significant change. I’m now 2% less Irish/Scottish and they have combined several European regions into the 77%. When expanding the “England, Wales & Northwestern Europe region, I get a map outlining this area.
In comparison, here are the ethnicity results of my sister before and after the update:
DNA Estimate of my sibling – After the update
Here, you can see that she is now 4% more Irish/Scottish than previously estimated and the remaining ethnicity has been split with the significant portion being England, Wales & Northern Europe and a smaller portion being assigned to Norway which is more specific than the previous Scandinavian region.
It is important to note that our DNA itself has obviously not changed. Ancestry has simply introduced more reference samples and improved the algorithm that is used to estimate our ethnicity. This is why I repeatedly tell those working with their DNA that this is simply an estimate and is like to change again and again in future updates. Theoretically getting more accurate over time. As you may notice while working on your family tree over time, you can generally estimate your own ethnicity as you slowly confirm DNA matches with others and confirm the origins of your common ancestors. This should corroborate the ethnicity estimate provided by the testing company and should come as no surprise to those experienced genealogists.
On May 2nd, 2019, Ancestry posted on their blog the following in regards to the updates:
We’re always looking for new ways to help support our customers on their journeys of personal discovery. Often that means updating our products and services to take advantage of the most advanced science and technology.Last fall, we introduced the capability to provide more precise ethnicity estimates to our customers using an algorithm that analyzes longer segments of genetic information. For some of our existing customers, this has meant that previous ethnicity estimates have evolved as a result of this new technology.
We recognize that an individual’s personal sense of identity is very important and that any journey of personal discovery may take turns that are surprising or unexpected. However, it is important to keep in mind that your DNA doesn’t change, but the science and technology behind understanding it constantly evolves and we endeavor to ensure that this cutting-edge science is reflected in our offerings.
All AncestryDNA® customers who have not already transitioned to their new, more precise ethnicity estimate will be transitioned starting May 30, 2019. If you received your AncestryDNA® results prior to September 2018 and wish to keep a record of your prior results, you may download them by July 20, 2019.
https://blogs.ancestry.com/ancestry/2019/05/02/understanding-your-new-ethnicity-estimate/
In the end, my advice to those new to using DNA as a tool for their genealogical research is to use this is a guide. Trust an ethnicity estimate to be just that…an estimate. You should always be working to confirm it’s accuracy through documented proof.