Thoughts on STRs and SNPs to untangle this Phelps group  By Doug Phelps, Phelps yDNA project admin 7/7/2018

In 2018 I worked very hard to figure a way to use the str markers of these tested descendants in a way that would unravel the tree of these Phelps going back to NE NC. As I see it, they are all are trying to see who descended from whom back to the 1700s… perhaps even further. As written here records are very hard to come by. We also should wonder if Cuthbert was the only patriarch there or were there other Phelps who came to America and were related somehow in the “old country” Try as I might (and I keep trying), at this point I don’t feel confident at all using their STR markers – even if all tested at 111. SNP testing is unfortunately your only realistic option to do that – and there are no ironclad promises for that either. Let me try to explain.

1. Str markers can mutate backwards (like 14 back to 13) or even jump in value more than one (like 12 to 14 thus indicate a strong GD but yet a single generation). SNPs mutate once forever and are handed down forever.

2. SNPs began with the dawn of mankind. They can be used to define ancient peoples and where they came from. As more SNPs mutated in ancient people to the present time we can see branches of ancient peoples, down all the way to each of us. The goal is thus defining YOUR most recent “terminal SNP(s)”. Your terminal snp defines all those very close men relatives no further back than 150 years +/- So when we see your SNPs we see some that started in the dawn of mankind, right down to the present time. With STRs even at 111 we have to go BACKwards in time, not having any idea of what they were before genealogy time.

3. So when we do a bigY SNP test against TWO of their Phelps, we are looking for which SNPs they have in common (which indicate about how far back was the common ancestor) and we also are looking for those “private” snps that each of the two men had since that common ancestor. I would expect anywhere from 0 to 4 of these private snps going back to a common ancestor (and also should see his SNPs) in the 1700s +/-. Those personal snps define each man’s “terminal SNPs” THEN others can test for just those snps $39 or $19 at Yseq.com to see which is youngest or oldest – thus aging the time of the branch IF one has at least one matching SNP. They have to be technically valid SNPS and they have to be NAMED in order to be able to tested. I feel confident that FTDNA's Big Y report will NOT provide that for people working on NEW genealogy SNP levels. IMO, at best, they will provide simply some unnamed snps that are not technicall checked out. A $49 analysis at Yfull.com provides exactly what is needed and provides a related tree even down to recent times. BUT it takes TWO Big Y tests analyzed at Yfull.