A few years ago I submitted a sample of my DNA to Ancestry.com, and they did an analysis of where my ancestors were likely from. Periodically they send me an update, as they grow their database and get more refined in their analysis. They sent this update below, with maps, in October, 2023.
I know very little about genetics, but I think that each person’s genes include about half the chromosomes from each parent, in a random mix. Brothers and sisters differ from each other in that they don’t inherit the same package of chromosomes from each parent. So if one of my brothers or sisters also had a DNA test, they would show the same heritage from different countries, but probably the percentage attributed to each country would be a little different.
Here’s the short version of how Ancestry’s ethnicity estimate works:
“How do we come up with your estimate? To figure out your ethnicity regions, we compare your DNA to a reference panel made up of DNA from groups of people who have deep roots in one region. We look at 1,001 sections of your DNA and assign each section to the ethnicity region it looks most like. Then we turn those results into the percentages you see in your estimate. Your genetic link to these ethnicities can go back hundreds of years or even more.”
Ancestry: “Your DNA connects you to 3 U.S. communities. Communities form when we identify AncestryDNA members whose ancestors probably came from the same place or cultural group.”
Early Pennsylvania Settlers 1700-1975
Early Connecticut & New York Settlers 1700-1975
Michigan Settlers 1800-1975
