McCarthy Surname Study

About us

The McCarthy Surname Project is testing for mutations on the Y-chromosome which:
(a)        distinguish McCarthys (and variants of the name) from one another
(b)        establish yDNA profiles associated with the various McCarthy septs, subsepts and agnomens and compare their inter-relationships with those suggested by both ancient and more recent written genealogies, thus testing the veracity of these records.
(c)        indicate probable time, and likely place in which common ancestors lived where these cannot be determined through traditional genealogical methods.
(d)        distinguish McCarthys (and variants of the name) from certain other southern Irish "Eóghanacht" families, the chiefs of which are claimed, in genealogies written many centuries ago, all to have common ancestry in the 2nd / 3rd century A.D. King Olioll Olum.

To maximise the resolution of Y-DNA analysis and comparison with other McCarthys among our 160 or so members who have tested the Y-chromosome, we have now reached the stage where a minimum of 67 markers for the y-DNA STR test is strongly recommended, and the full 111 marker test is preferred. In some cases the haplogroup defining common ancestry 1,200 -  3,000 years ago can be easily inferred from these results, so does not need separate testing. However, as new, recent, defining SNPs are discovered (e.g which may be less than 1,200 years old), specific testing for these will be selectively recommended to confirm members' position on the McCarthy family tree.