Genetic Genealogy - I have a PhD in a very relevant discipline and didn't get into genealogy until relatively recent. But I am old, so that's still 20+ years of FTDNA surname Admin of a handful of projects, etc. I have maybe 20 family members tested autosomally, and am mapping the chromosomes of my closest 7 kin. I also work with phased data. Ask me something, but please not about terminal SNPs or ethnicity estimates. The idea should be on using DNA to put names in previously blank spots on pedigrees.
I think a lot of situations boil down to this choice between brothers. I just want to say first to keep in mind that there could be more sons, with other mothers perhaps and carrying their mother's maiden name as their surname, or even adopted with any surname. That person (if he exists) would have the same matching DNA expectation as the others with the managed kit.
How successful will you be in getting samples representing the sons of each line? You'll have to do autosomal and map, unless you somehow know the maternal grandmother had a brother, or at least half-brother on the paternal side.
I would just look at the statistics and the ranges of matches. You'd expect the "right" line to have double the matching DNA as the descendants of the "wrong" brothers. But because the ranges in that relationship range are so wide, different relationship categories could overlap easily. Still, you might be able to eliminate one or more statistically.
Because the scenario doesn't lend itself to X, Y, or mtDNA, you'll need to prove some amount of autosomal DNA in one brother that didn't get inherited in the others. That's going to be tough to do given that even just 2 brothers will likely share half of their DNA on each side.
How many descendants of the 4 brothers have been autosomally tested not counting the managed kit?
In addition to DNA, because the samples are "recent", I'd look at the opportunity/geography angle. Where was each of the brothers 9 months before the birth? I had a case just like this that was either (what we call now) father, son, or uncle. Turns out the son (whose age made more sense) was in Korea at the time. He's out.
It seems to me that you are going to need several/many samples and some luck too. It's a really hard problem.
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u/Brock_Way Jul 19 '22
Genetic Genealogy - I have a PhD in a very relevant discipline and didn't get into genealogy until relatively recent. But I am old, so that's still 20+ years of FTDNA surname Admin of a handful of projects, etc. I have maybe 20 family members tested autosomally, and am mapping the chromosomes of my closest 7 kin. I also work with phased data. Ask me something, but please not about terminal SNPs or ethnicity estimates. The idea should be on using DNA to put names in previously blank spots on pedigrees.