Date: May 14, 2019 10:42AM
Here, Tevai, is one such report I was able to find that somewhat answers the question of different findings per different readings of the same results as they become narrowed down and (maybe or maybe not,) more focused:
These companies use what is called reference DNA to figure out where your DNA came from. This reference DNA is the DNA of people whose families have stayed in a part of the world for a long time. Or who have very detailed family trees.
The companies then compare your DNA to the DNA landmarks they found in these families. The parts that match that group of Germans is German, the parts that match that group of people from the British Isles is English and so on.
Sounds easy enough but most people are not like the reference group. They have lots of different ancestral DNA scattered in chunks throughout their DNA. This is where things can get tricky.
To get around this mixed DNA, the computer program analyzes small sections of the DNA at a time. These “windows” have around 100 or so DNA markers in them which translates to thousands of such windows."https://genetics.thetech.org/ask-a-geneticist/same-dna-different-ancestry-results
And then this:
"Here’s something else that’s important to remember: Ancestry DNA tests don’t tell you where each member on your family tree lived. Instead, they tell you how much of their DNA you’ve inherited.
That’s why siblings can get different reports from DNA ancestry services (even though they share the exact same relatives). “It’s possible that your brother might have inherited a piece of DNA from one of your ancestors that you did not,” Pickrell says....
As you move further and further back in time on your family tree, “there’s some possibility that you’ve inherited no DNA from one of your ancestors,” Pickrell says. Does that mean you’re not related to that person? No. Does that mean you’re barred from making pierogis with their time-worn recipe? Of course not. They’re still a part of your family tree, and a part of your heritage.
DNA is not the same as heritage. DNA ancestry tests sort your DNA by the geographic regions you likely inherited it from. But not everything about our family histories is geographic.
These tests don’t tell us about the languages our ancestors spoke, the food they ate, or whether they were celebrated or persecuted. They don’t say much about how our ancestors lived or traveled." (All I know about the Swiss (if it is even accurate) ancestry is that they lived within the past 200 years. Not whether or when they may have immigrated or whom they may have married.)
It sure does get intriguing though.
That's why many people get hooked on genealogy later in life. It used to bore me to tears when I was a child. Not any more. Now there isn't enough time in the day to make new discoveries or find new connections.https://www.vox.com/science-and-health/2019/1/28/18194560/ancestry-dna-23-me-myheritage-science-explainer