Hi all, hope you can help me understand a problem.
Trying to identify Y-line 2nd great grandfather. Nothing is known about him other than he died after knocking up 2nd great grandma.
I performed the Leeds method on my DNA matches and was left with a group of American (I am Aussie, so is whole family) matches who were not matching with any one. I put them in the Unknown 2GGF bucket. Did genealogy, found out who the ancestral couples were, put them into my tree and resulted with ThruLines galore, matches going back to the 1700s. Mystery solved, at least as far as who the ancestral couples were.
Got my Dads DNA results back a couple of days ago and was excited to dig in and see if I could figure out the specific identity of Dads great grandfather only to realise - with abject horror - that all of these American matches were assigned to his as MATERNAL and according to that could not be cousins of our Y line ancestor. Now, I know that SideView isn't perfect but I need a second opinion from you learned folk.
My main points of contention with these results are:
1) I triangulate with all of these matches on Chromosome 22. We share one segment of between 29 to 35 cM depending on the person, and from what I understand that tends to confirm a recent common ancestor. In my Ancestry, my Paternal Ch22 is designated Welsh, and I have confirmed Welsh ancestry for this group through available trees. However, on my Dads ancestry, his Paternal Ch22 is designated Welsh as well, while his Maternal is English - yet these matches are assigned Maternal.
2) There is a gaping hole on the paternal side that these matches fit into. There are no holes on the Maternal side. When I do ThruLines for my Nans side going back to 4th great grandparent level, I get cousin matches galore for all lines. When I look at that, I just cannot see anywhere that there could have been a non paternity event to place these roughly 80 American 3rd cousins.
3) I have 2 Aunts, one matches to this cluster on Ch22, the other doesn't. The one who doesn't, when I put the American ancestral couples into her tree, she does match to a few dozen cousins that come from the families of both ancestral couples, and when I investigate them, they are all labelled as Paternal, which is why I was so certain in the first place I had these American cousins correctly placed.
Unfortunately, the Aunt who does match them has not done Ancestry, only MyHeritage so I uploaded her DNA to Gedmatch and confirmed triangulation there.
4) While no one on my dads Paternal side triangulates with these American cousins, no one on my dads Maternal side does either! It's just this group of people that me, my dad and my Aunt all triangulate with on Ch22. It isn't in a pile up region and it is one segment of at least 29 cM. The matches we are looking for to identify this mystery ancestor will be at the 3rd to 4th cousin level, and according to DNA Shared cM project, this cM segment lines up perfectly.
5) Perhaps most importantly, if I take those American cousins and shovel them into the Nan bucket, there is just no one left over to represent this 2nd great grandfather. Every 4th cousin or closer is matched to their respective line.
So after all of that, my question is simple: could SideView have phased my Dads Ch22 incorrectly, or failing that, just assigned these American cousins incorrectly because there were no other close matches to my Dad who triangulate with them?
Thanks all for reading through that, it was a lot!
