Michael Cooley's Genetic Genealogy Blog GEN • GEN
18 September 2016

Big Y Results for Cooley Group CF04

FTDNA has looked at ten million positions on the Y chromosome of a descendant of Robert Cooley (1754-1794) of Luzerne County, Pennsylvania. The tester's lineage comes down through Robert's son William. There are no other CF04 Cooleys with which to compare the results, so we don't have a Cooley Most Recent Common Ancestor (MRCA). However, a Davis has tested, and the compared results provides an inference of a MRCA who lived 950 to 1450 years ago, or more than 600 years before Robert's birth. Here's my first rough analysis of the test results. They will be further analyzed by at least two more research teams.



The data in the boxes are simple mutations called Single Nucleotide Polymorphisms (SNPs). Those in the green boxes are newly discovered and are mostly unnamed. (See article 24 for an explanation about SNP names and designations.) The unknown MRCA was born with all the SNPs listed above him. We know this because both testers have them — and they're the first testers found to have them. Consequently, we have a newly discovered haplogroup, this one consisting of five previously unknown SNPs. For now, we can refer to the block as T22462388C, named for the first listed SNP.

The SNPs in the second set of green boxes emerged sometime between the births of the MRCA's sons and of the testers. They are known as "private" SNPs for the simple reason that these SNPs are presently unknown to exist outside the tester's own lineage. Understanding "presently known" is key to envisioning the process. Davis was the first of the pair to test. The five green SNPs now attributed to the MRCA were once considered private to Davis — no one else was found to have them. That has changed (and there will be many more changes). For now, we have one new haplogroup and soon those SNPs will be given names and placed on the world-wide SNP tree right below YP4944, itself one of many SNPs that have only recently been discovered, likely with thanks to the Davis tester.

The next level of SNPs can be broken up in the same way. For example, some of those nine Cooley SNPs will belong to the tester descended from Robert's son Daniel, rather than his brother William. Those that the new tester share with the current tester will have belonged to Robert Cooley, the two testers' MRCA. The SNPs left over will be the new set of private SNPs for #76628, say two or three or even zero. In other words, we might find something like this:


Again, this is made up. Those nine SNPs could break up in any number of ways. See the second graphic in article 22 for an illustration of that. It could turn out, for example, that Daniel Cooley of Maryland was closer related to John of Yorkshire than to the Pennsylvania Cooleys. We could determine that if a representative of each line tested. For some families, clues can be found among the STRs. My own group, CF01, has at least two strong Y-STR indicators. CF04 may have one in DYS449: The two Johns with known English origins have 32 repeats; the Davis has 33 repeats; and the American CF04 Cooleys have 33 repeats. But the comparisons begin to break down from that point. It's not surprising because STRs are quite volatile. Nevertheless, let's look at genetic distance — the number of STR differences between two people.



Interestingly, the Davis tester and the Daniel tester have the greatest genetic distance, a value of 8 — and I believe Davis, as well as the Daniel Cooleys, had roots in Maryland. Yet Davis is closest to John of Yorkshire. Does that mean his family was from Yorkshire? Possibly. Our only other tester so far is the Robert descendant, and he's also a genetic distance of 2 from the Yorkshire Cooley. Remember, though, that these STRs belong to the testers, not to the ancestors! There were a number of intervening generations since the MRCA lived. Anything might have happened. Still, it's likely that most of the STRs that are shared by all of CF04 did belong to the MRCA. However (there are always caveats when we speak about STRs), those numbers can go back and forth, so the truth can be is veiled. STRs are tricky. Not so with SNPs. Because of the triangulation (again, article 22) between the Big Y testers and the extremely low rate of mutation for SNPs, we know what SNPs the Cooley/Davis MRCA in fact had. Still, the close genetic distance between Yorkshire John, Robert Cooley, and William Davis is intriguing. A Big Y for the Yorkshire descendant will likely shed some light on it.

Further exploration of the STRs can be found at my Y-STR pages for the Cooleys. Click on CF04. But let me once again caution that, unlike SNPs, STRs are fickle. We can spend hours exploring them but the SNPs can destroy that work by providing a far more accurate picture.

What have we learned? The genetic make-up of the testers' Y chromosomes. But by comparing the Cooley/Davis fingerprints, we've managed to point in the general direction of a man who lived, perhaps, around the year of 800 AD (give or take a couple of hundred years or more). He might have lived squarely in the middle of the early Viking excursions into Northumbria. This makes sense because the CF04 Cooley Y chromosome has a likely Scandinavian origin.

What do we stand to learn? The relative relationships between the various CF04 Cooley families — a relationship that will prove to be far more accurate than my guess two graphics above, even with STR genetic differences. And what will additional Big Y testing tell us? We'll have several Y chromosome profiles and baselines from which we can judge future CF04 testers, filling in some of the blanks. And it's possible that the group will tie in with someone who has traced a lineage back to the early Norman period, just as has happened with the CF01 SNP connection to the Cochran clan of Scotland. We've just made a significant step in the right direction. It would be wonderful to see the momentum continue.

There are still eight SNPs I've been unable to make a determination about. (I'm new at this.) But I've submitted most of the new SNPs to yseq.net for further analysis and naming. If we can get the raw data file to Yfull.com, they'll also learn more. Eventually, FTDNA will get to it (don't hold your breaths), and the R1a Project's team will also look at the results. I'll update the first graphic as new information comes in. In the meantime, as always, feel free to ask questions.