To try to help explain the Y testing I’ve done, I have a man chart of the men involved in our family Y testing extravaganza. At the top is patriarch Albert Thompson born in 1870 followed by his sons Ray Thompson and Francis Thompson. The dapper looking boy on the left is my grandfather.
This should help describe the layers. Blue boxes are filling in for men without pictures. I’ve labelled the testers under their squares. Basically my test is first. Then I ran test two with a second cousin of my father. If we had matched you can go all the way up to the intersection with Albert Thompson because that is where both sides meet.
Since we didn’t match, then we have to test a little closer to home, and there you have the test 1 match and test 2 match. Those tests can only confirm to their first intersection. So, my cousin and I testing verified our grandfather. Test two matches verify their grandfather (who is my grandfather’s uncle). All that I can say is that my grandfather does not match his uncle as Y test 1 and Y test 2 do not match each other. Without siblings for my grandfather, we cannot confirm my great grandfather with Y testing.
Now I’ll look to 23 and me to provide answers as we have Y test 2 candidates run autosomal DNA tests. Y test 2 and my father should share great grandparents, if they show enough of a match to suspect that they share a single great grandparent (Ida Williamson – wife of Albert), then it will be more likely that the Y break happened at my great grandfather and it would confirm him. If not, then I would suspect that the break happened at my grandfather and we would more likely be unrelated to the Thompsons.
If it looks like we’re unrelated to the Thompsons then the best bet for finding our Thompson/Williamson family would be to have both Y test 2 cousins run Autosomal tests at 23 and me. Where they matched each other would represent the contribution of their grandparents and make it easier to track down Williamson and Thompson matches.
We will also want to extend at least one of the Y tests out to 37 or 67 at FTDNA, because we’ll want to clearly identify that main Thompson line. If they’re P312, their results would line them up with other Scots Irish Thompsons very well, but it would be nice after all this time to get that confirmed Thompson match and we can only accomplish that with more markers.
There is also the tiniest of possibilities that the break in the Y didn’t happen on my side of the tree but actually happened with Francis (my grandfather’s uncle), but I think that is very very unlikely given how well they are already lining up with other Thompsons and how poorly we have. It’s been pointed out to me that the only way we’ll answer that is to find another Y line of Albert Thompson to test. Right now I think that leaves us Cuba Thompson the only other Thompson in this family, I’ve been able to find children for. He had a son named Gerald or Gerry or Jerry born in the 1930’s to his wife Onda Harris.
There is also a very very tiny chance that we actually do match up and they are a super freak mutation away from us and towards “normal” European. Considering we fit with a cluster of people who all look like us at this level in Z14, that seems like a really fringe chance.