Reading Your Ethnicity Estimate
Remember when you got your AncestryDNA® test results? You likely recall the anticipation, the excitement of what you might discover—and the fun of sharing your ethnicity estimate results with family.
But people often don’t realize how much information is contained in their ethnicity estimate. An ethnicity estimate actually has two major pieces of information:
Ethnicity regions are the most well-known part of the ethnicity estimate and come with percentages, like 25% Sweden & Denmark or 10% Senegal.
They are really broad, and they often encompass one or more modern-day countries. This part of the ethnicity estimate can also reach back more than 20 generations.
The communities portion of the ethnicity estimate does not have assigned percentages. Instead, communities represent people who share a significant number of matches with each other and likely descend from a group of people with a common history.
Looking at your communities results can give you a more granular understanding of where your ancestors may have come from—sometimes down to the region of a country or even a county. These results also reflect the more recent past, about 5-20 generations ago.
How Does AncestryDNA Assign Ethnicity Regions in Your Ethnicity Estimate?
Assigning ethnicity regions based on your DNA is a complex process. It’s based on probability, statistics, and shared DNA. Here’s a closer look at how Ancestry® scientists approach the topic of ethnicity regions.
First, our scientists create a reference panel, which is made up of reference groups. Each reference group has the DNA of people whose family lived in a certain part of the world for many generations. Each reference group represents an ethnicity region.
Since 2022, more than 80 reference groups have been included in the AncestryDNA reference panel.
When a customer takes an AncestryDNA test, our scientists compare their DNA, piece by piece, to see which reference group each piece of that customer’s DNA most closely resembles. The ethnicities assigned to each piece of DNA are then totaled up and the percentages are calculated. If 15% of the DNA pieces analyzed look most like the France reference group, then the customer gets 15% France in their ethnicity estimate.
AncestryDNA continues to add samples and update its reference groups to improve precision and include additional ethnicity regions in AncestryDNA test results. Also, AncestryDNA may update the way it analyzes your DNA as the technology becomes more precise.
Updating our reference groups and the way we analyze your DNA means that over time your results may also be updated.
What Are SNPs and How Are They Key to Your Ethnicity Estimate?
To estimate your ethnicity, an AncestryDNA test looks at about 700,000 markers in your DNA. Those markers are called SNPs (pronounced “snips”). SNPs are common and shared genetic variants at specific sites in DNA, where one nucleotide letter in your DNA is commonly substituted for another.
For example, the SNP called rs122 could occur at the 1,000 base position on chromosome 1. At that position, some people may have an A in their DNA, and others may have a C. Because you get one letter (or allele) from each biological parent, your genotype could be AA, AC, or CC.
Each possible outcome at each SNP has a probability for how likely it is to show up in each region represented by the reference panel. We’ll pretend that rs122 occurs at the following frequencies in the populations Ancestry defines as Indigenous Americas—Mexico and Spain:
A = appears 5% of the time in Indigenous Americas—Mexico populations and 75% in Spanish populations.
C = appears 95% of the time in Indigenous Americas—Mexico populations and 25% in Spanish populations.
So, if you have AA at rs122, it’s more likely that specific part of your DNA is Spanish than Indigenous Americas—Mexico. If your DNA reads CC, then the opposite is more likely.
One SNP doesn’t tell us much about your ethnicity, but when we apply the same process to thousands of SNPs, and then do the math, the total becomes the basis for your ethnicity estimate.
Why Do Ethnicity Estimate Percentages Have a Range and How Is it Determined?
In addition to the most likely estimate, our algorithm also generates 1,000 likely estimates using the probabilities learned from comparing your genetic data to our reference panel.
We use these 1,000 likely estimates—which may be different from the most likely estimate—to figure out the range. The way we calculate the range depends on the region and the value of the most likely estimate.
Here’s an example of an AncestryDNA ethnicity estimate for someone with strong ties to the Americas.
In the example above, between 10% and 20% of this customer’s DNA appears to match the Indigenous Americas—Mexico reference panel, with the most likely percentage being 20%. To find out your range of likely percentages for an ethnicity, click on the region in your results.
These ranges are important to look at, especially for results with lower percentages. In these cases, the range can sometimes include zero. This means it is possible that your ancestors didn’t live in that region or you didn’t inherit any DNA from ancestors who did.
But My Family Never Lived in [Your Mystery Region Here]?
So how do you interpret your results if your ethnicity estimates show that 7% of your DNA is from Scotland, for example, and you’ve never heard of anyone in your family being from Scotland? This is where the maps and the polygons drawn on top of them can help.
By clicking on Scotland, the first thing that pops up is a note that this ethnicity is also found in England, France, and Northern Ireland, among other places. These areas are highlighted in the polygons on the map. So, already there are new possible places the ancestor who passed this down might be from.
These drawn shapes make sense because shared genetic history doesn’t always match modern national borders. Throughout the ages, as people crossed borders we see on the map today, they took their DNA with them.
There’s a long history of movement among the places that fall under our Scotland region—the early Celtic settlers of Great Britain, Ireland, and Brittany, and those who crossed the Irish Sea to Northern Ireland as part of the Plantations of Ulster in the 17th century.
The result is a map of shared genetics that is located primarily in Scotland but reaches across national boundaries. In fact, on average, people native to England who take a DNA test see about 20% Scotland in their results.
So, your ethnicity estimate can provide insight not only on where your ancestors might have lived but also allow you to trace the path of your ancestors.
Why Does My Ethnicity Estimate Differ From My Family Story?
Your genetic ethnicity estimate tells you about your possible historical origins, not necessarily about where you live today. AncestryDNA® genetic ethnicity estimates go back hundreds to more than a thousand years, when populations and the boundaries they claimed were often very different. This might lead to a different genetic ethnicity estimate than you expect.
While someone’s language, name, or culture may change when they move to a new location, their DNA doesn’t. This can lead to surprises in your genetic ethnicity. For instance, if your Italian grandmother had ancestors who migrated from Eastern Europe hundreds of years ago, you might show up as having Eastern European ethnicity instead of Italian.
The opposite can also happen. DNA is passed down randomly and the amount of DNA you might inherit from any particular ancestor decreases with each generation. That means you can have an ethnicity you know of in your family history that doesn’t show up in your ethnicity estimate.
If you haven’t looked at your ethnicity results in a while, go back and give them another look. You’re much more than a pie chart and a handful of percentages. And so is your AncestryDNA ethnicity estimate.