Short version: The accurate way to read an ethnicity estimate is, “Ancestry is 38% sure I have ancestors from Nigeria”, not “I am 23% Nigerian”. Replace the company and ethnicity appropriately.
I received my AncestryDNA results several years ago. After breathing a sigh of relief looking at the DNA matching, I looked at the ethnicity results. I immediately knew something was wrong, but I accepted the results. I read them as, “I am 23% Nigerian, 12% European, etc.”.
Looking at the list, while my Asian DNA was on there, I knew the European estimate was wrong. Half of my great-grandmothers were so fair they could pass for white. The family story about having a Native American great-grandmother died that day. My results inspired me to learn more about my family DNA history.
Some time later, I received notification that my ethnicity results changed. They were more accurate than ever!
What an Ethnicity Estimate Really Means
Our DNA does not have a race or ethnicity gene. Race is a social construct, not a biological one. The proper way to read an ethnicity estimate is, “Ancestry is 38% sure I have ancestors from Nigeria, 18% sure I have ancestors from Europe, etc.”.
See the difference?
The companies providing ethnicity estimates use a reference panel of people they tested that, allegedly, have a long history living in a particular area. Then, they compare your DNA with those of the reference panel. Percentages, based on algorithms, are calculated based on the closest matching populations.
You cannot DNA match a population unless it is represented in their reference panel. The estimate can also show the ethnicity of where the ancestry originated from, not where they resided.
How Accurate are Ethnicity Estimates?
When a company matches your DNA to a location, it is reasonably accurate you had ancestors from that area. The estimated numbers are not accurate. Since ethnicity is not in our DNA, the estimate is only as accurate as the reference panel.
Ethnicity estimates lead people to think an ethnicity is missing where it might not be. Companies do not do much to correct this. They will explain how one gets 50% of their DNA from each parent, meaning, you are also missing 50% of their DNA. Everything is not passed down. They explained, using Native American as an example, your parents, or grandparents might have had it, but it was not passed down to you. What they do not say enough, in my opinion, is that their reference panel is incomplete.
Ancestry is Updating their Reference Panel…again
I noticed Ancestry is updating their reference panel in August 2022. They are adding 8 new regions.