My Ethnicity Part 1 — How it Works

When I had my DNA tested, I received an initial ethnicity report that showed the percentage of my DNA broken down into several ethnic/geographic groups. 

Don't get too attached to that image and those percentages, because I honestly couldn't even recall what those initial percentages were. Why couldn't I recall those? First, because I didn't have a DNA test done to find out my ethnicity. I already had a pretty good idea of what my ethnicity mix was. I did it to connect to others who share DNA with me, discover long lost cousins and find relatives who are researching my same family. And second, because my ethnicity estimates have changed several times since I first received them. Why did they change? Ancestry's ethnicity estimates are based on other DNA tests and what the people attached to those tests have input about their family trees on Ancestry.

That doesn’t sound very scientific, does it? I mean, in many cases, that amounts to here-say. Many of the people who have DNA tests done might not even add a tree to their DNA results on Ancestry. If they do, it’s very small and includes their most recent ancestors, usually from memory.

In other cases, there is a tree, sometimes extensive, but the research is, well, iffy at best and downright wrong at worst. Those who do not take the time to understand the complexities of carrying out accurate genealogical research can easily grab records for people with the similar names to a known ancestor. That can lead to completely wrong information being attached the person who did the test — including geography and ethnicity — which can skew the database. And the more people with incorrect trees, the more inaccurate the ethnicity database.

But it’s not as bad as it seems. Ancestry doesn’t use just the results from its own database, and it doesn’t place a lot of stock in one person’s tree. Experts utilize DNA information from various other sources, including local genetic studies designed to identify people with long family histories in one geographic area.

People should be aware that the ethnicity estimates on Ancestry are just that — estimates based on the information available at the time. But the more people who do DNA, the larger the samples for analyzing ethnic and geographic identifiers. And if there are anomalies (from mistakes made in research), they are typically written off as just that. It is the larger consistent data that is used by the algorithms.

As a result, ethnicity estimates change. In some cases, results may be refined to show more granular details and in others they may change completely.

Which leads to my Scottish question…