Are DNA ethnicity results influenced by your online tree? And how do DNA testing companies choose what geographic regions to report? Your DNA Guide has answers.
Many genealogists have taken autosomal DNA tests at one of the three major DNA testing companies with the hope of securing a glimpse into their past. Specifically, many take DNA tests looking for confirmation of a particular ancestral heritage; others are just curious to see what the ethnicity results will show. Though their purposes in initiating the testing may vary, the feeling of bewilderment and befuddlement upon receiving the ethnicity results is fairly universal.
I get a couple of common questions about DNA ethnicity I want to answer here.
Do family trees influence our DNA ethnicity results?
The answer is an unequivocal “no!” None of the testing companies look at your family tree in any way when determining your ethnicity results. However, the results are dependent on the family trees of the reference populations. The reference populations are made up of large numbers of people who have their family history documented for many generations in that region. The data from these reference populations create genetic patterns that represent their region. The testing companies compare your results to theirs, looking for the patterns in your data that will connect you to that region.
How do these testing companies decide to divide up the world?
All of the companies handle this a little bit differently. Let’s look at Ancestry as an example. When you login to view your ethnicity results, you can click on the “show all regions” box below your results to get a list of all of the possible categories that your DNA could be placed in. Ancestry now distinguishes more than 500 global regions, which combines the ethnic groups they identify by those reference populations and their Genetic Communities.
Clicking on each individual location will bring up more information about that region. For example, the England, Wales and Northwestern Europe category looks like this at AncestryDNA. If you click “Read more,” you’ll find that this region is “primarily located in England, Scotland, Wales” and is “also found in Ireland, France, Germany, Denmark, Belgium, Netherlands, Switzerland, Luxembourg.”
The history of Britain is often presented as one group of invaders after another displacing the native population. The Romans, Anglo-Saxons, Vikings, and Normans all left their mark on Britain both politically and culturally. However, the story of Britain is far more complex. In fact, modern studies suggest the earliest populations weren’t wiped out, but adapted and absorbed the new arrivals. Basically, this is telling us that people with generations of ancestry in Great Britain, are quite a genetic mix from many areas.
In the end, the ethnicity results reported by each DNA testing company are highly dependent on two factors: the reference populations they use to compare your DNA against, and the statistical algorithms they use to compute your similarities to these populations. Every company is doing both of these things just a little bit differently. AND, as you may have noticed, ethnicity regions and computations at most of the testing companies continue to change as they get more data into their systems. (Most recently, Ancestry updated theirs in April 2019: read more about it here.)
If you want to get another take on your ethnicity results, you can download your raw DNA data and upload it another company: Family Tree DNA and MyHeritage both accept uploads. Another option is to head over to GEDmatch and try out their various ethnicity tools. Most people have found after seeing their ethnicity reports in multiple places that their “true” ethnicity results are probably somewhere in the middle.
While these ethnicity results can be interesting and useful, for most they will just be a novelty; something interesting and exciting. I have found that their most useful application is acting like a fly on a fishing line. They attract our family members into DNA testing where we can then set the hook on the real goal: family history.
What you should do next
There’s lots to learn about ethnicity results and it can be hard to know where to start. That’s why we’ve compiled our free Ethnicity Quick Start guide. You’ll learn applicable tips for how to use your DNA ethnicity results and feel like a pro in no time!
Originally published at www.genealogygems.com. Updated on Your DNA Guide in 2019.