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Preliminary results about our Callaghan Y-DNA study.

Since its inception, our Callaghan Y-DNA Project has had additional Callaghan men test from Ireland, Australia, the UK , the States and New Zealand (approx. 75).   

First this is primarily a Y-DNA study.  Y-DNA is past from father to son virtually unchanged over generations & with only minor countable mutations. Y-DNA predates surnames.  Like all Clans or Septs not all Callaghan men share the same Y-DNA.  Of course many of Callaghan's are interrelated through other common ancestors not just the Y, especially if their families lived in the same general area for generations.     Family Finder has been helpful in connecting some us if we are not connected on the Y.

The majority of Irish men carry the R1b Y-DNA.  This is true of most men in Western Europe.   Most of the Callaghan men who have tested are from the R1b branch.   From the R1b branch there are a number of leaves (SNPs)  being studied that are particular to the Irish. We have a number of those leaves in our tree.   I will point out the three major R1b clusters in our study:

R1b  to  L226:  We have 14 Callaghan men who are presumed to be L226 or as some call it Type lll Irish.    The L226 SNP (mutation ) is carried by many men with the O'Brien Surname (however L226 is not exclusive to the O'Briens).   As I understand it the present day Chief of O'Briens of Thomond has tested and is L226.  Some suggest that this is the Y DNA which was carried by Boru himself and his progeny. See http://www.irishtype3dna.org 

R1b  to  DF21:   We have 6 Callaghan men who are  presumed to be DF21.   These Callaghan men closely match a branch of McCarthy's. (Like the Callaghan's the McCarthy's have a number of branches off of R1b)   Some have suggested that is the common connection between the 2 historic families.  Time & more testing will tell.

R1b  to  M222:  We have 17 Callaghan men who are M222 or Type 1 Irish.   A 2007 Trinity College study correlated M222 with the famed & mythical Niall of the Nine Hostages.  Some of our M222 Callaghan's are from the North so no surprise there.  However some of the M222 Callaghan's are from Cork & Clare. See  www.irishtimes.com/news/science/the-genetic-imprint-of-niall-of-the-nine-hostages-1.1771373   (good summary of Y-DNA Surname Studies)  According to the National Geographic Genographic Project M222  “is the ancestral lineage of the Ui Neill and Connacht dynasties.”


We also have some Callaghan men who are not on the R1b branch.   5 Callaghan men belong to the haplogroup J2 and look to be fairly closely related with one another.  These men are a minority but their ancestors may have been in Ireland for a very long time. 

You can browse our Callaghan results here:  www.familytreedna.com/groups/callahan

Obviously only a small fraction of Callaghan men have tested their Y DNA but these 4 clusters (leaves)  are real & some of these men share common ancestors in fairly recent time. If you know of other Callaghan men who may have an interest in our project would welcome them. The more Callaghan's who test the more we can fill in the branches. 

We also welcome those folks who have tested through Family Finder that have a Callaghan ancestor.

December 20, 2015