McCool y-DNA Test Results

In general, y-DNA tests provide information about deep historical roots (in one line) rather than recent common ancestors. However, it looks like McCool DNA tests may be able to provide more information than usual about our American McCool lines.

I've been able to locate eight McCool y-DNA tests on FamilyTreeDNA (as of September 2017). Five of the tests definitely match to our family, one definitely does not, and the other two have the potential to unlock some secrets as to how our McCool lines may or may not be related. I've submitted requests to the tested McCools asking them to share their genealogy trees so we can learn more.

Who Should Test?

More tests are always better than fewer tests. Although yDNA mutates at a moderate pace and can vary from father to son and even brother to brother, most people only test one male per extended family (out to second cousins or so.) Most of the time, people that closely related will have identical (or extremely similar) results. Please test at the y-37 level or higher; y-67 or y-111 are better. You also have the option to upgrade in the future.

Once you've tested, please join the following FTDNA groups:

  • All McCool testers should join the Cole surname project.
  • Anyone with a predicted haplogroup of R-M269 should join the R1b Project.
  • It looks like our McCool lines are members of R1b subclade L-513. Join the R-L513 Project for great advice on any additional testing needed.

Questions? Send me an email at .

Known McCool y-DNA Test Results

Based on these tests, we know that our McCool ancestors are members of the very broad R-M269 subclade of the R1b Y-chromosome haplogroup - the most common Western European haplogroup. About 82% of the citizens of Ireland and 70% of citizens of Scotland are R-M269 members (although my Ireland-surname line descends from a much rarer R-1a haplogroup in Ireland/Scotland.)

Here are the 8 y-DNA tests that I've found. Click on the image if you want to open it in a new browser tab - and click again if needed to zoom to a readable level:

Toberhead McCool Lines

I've been able to match five of these tests to descendants of our Toberhead McCool family. It's quite possible that two of the others are also related to our family. The person with the I haplogroup either has a non-paternal event in his ancestry or he's simply the only example so far of a completely unrelated McCool line. Here are the five lines that I've matched - along with an example of where our line is believed to fit.

Click on the image to open it in a new browser tab - and click again to zoom in to a readable level:


Are we related?

Here are the GEDmatch Kit #s for my father and mother:

GI: A909282
CL: A216073

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