Michael Cooley's Genetic Genealogy Blog
15 August 2020

Studying the Y Chromosome Honors Your Ancestors' Truths

Let's start with a reminder: Each marker listed below originated in a man born at a specific place and at a specific time. All markers that preceded said birth, were passed to his sons and are archived in all his living, male-derived descendants. That's the beauty and the power of Y-DNA — history is organically etched into our cells.

Although I don't descend from William Cooley (-1817), shown below, I've been interested in him for fifteen years. He, my John Cooley (c1737-1811), and several other equally unrelated Cooleys were implicated in a fallacious 1930s "genealogy." Lura Coolley Hamil proposed that virtually all Cooleys not included in Mortimer Cooley's The Cooley Genealogy (published several years later) were, somehow, descended from an early Dutch immigrant named Kool. Yet seven of the lineages are shown to be of varying Y-DNA haplogroups. (This William, now of Group CF10 of the Cooley DNA Project, became the first evidence I uncovered that would lead to verification of the problem.) Hence, I refer to the results of Hamil's work (she died of a heart failure before finding a publisher) as the Bogus Dutch Cooleys.

This particular tribe of Cooleys was decidedly not Dutch. William (who married Elizabeth Firmin, probably in Maryland) was almost certainly the man described in Irish Emigrants to North America as "born 1753, a founder in Dublin, emigrated from London to Maryland on the Rebecca as an indentured servant." Enough of this is echoed in a biography for his grandson, John Cooley of Fayette County, Pennsylvania for it to be considered our man.1

Among the tested descendants for CF10, William presently has haplotypical matches — 64 of 67 markers — to John Cooley (1749-1813) of New Jersey. No genealogical connection can be made. In addition to the one Big Y among these Cooleys (from which this graphic is derived), the project has managed only an added SNP test for one of John's descendants. The group also has tell-tale matches to Cameron, Scully, Carroll, and Keenan.

Decidedly not Dutch.



Cooley Group CF10 (R1b-S984)


There's quite a lot left to be sorted out here. John's descendants will undoubtedly be positive for the S984 haplogroup (all 31 SNPs) and will probably have some of William's novel SNPs, which would constitute a new subclade that likely emerged well within the genealogical time frame. A Big Y among the Johns, which sequences up to 15 million position on the Y, will reveal something of the degree of relationship between the two men. The test won't tell us whether they were brothers or cousins. But it can put us well-within the ballpark. (Actually, their immediate descendants might fall into the purview of autosomal testing.)

The Scullys are of interest to the project. The number of average SNPs between Scully and Cooley up to their common haplogroup is only four, suggesting the common ancestor might have lived only two hundred to four hundred years ago. And the roughly 650 STRs sequenced for the Y-700, tells us the genetic distance (GD) between Cooley and Scully is 8. That might roughly put the common ancestor in the 16th or 17th century. But, remember, we're talking only about only on Cooley Big Y. Estimates could change with additional testing. (The leading S in Scully is probably coincidental but interesting nonetheless.)

The forest that is S984 is formidable. Its parent, FGC3899, is one of five subclades of DF5, which could be as old as 4,000 years. Only time and several testers will penetrate its otherwise surmountable defenses. But there may be a sufficient number of near-matching non-Cooley families to acquire a sense for the population these Irish Cooleys emerged from. Just as I owe it to my John Cooley (Cooley Group CF01) to learn something of his heritage, this family deserves like justice. Y chromosomal testing provides an opportunity to clarify a murky past and to move this immigrant family into the future with a bit of a dusting off.


1 John M. Gresham, editor, "John Cooley," Biographical and Portrait Cyclopedia of Fayette County, Pennsylvania, (Chicago: John M. Gresham & Co., 1889), 421.