Welcome to the Scrapbook pages for the McCarthy Surname Study, which analyses the Y-DNA of men named McCarthy or a spelling variant or agnomen associated with this name. The files made available below support the main Study website at: https://www.familytreedna.com/groups/mccarthy-surname-study/about
Our McCarthy Surname Study books
We have published (via Amazon) Kindle and paperback versions of two books entitled Tracing Your McCarthy Family Tree.
Book 1 is for complete beginners but takes research up to the point of ordering a Y-DNA test. It includes chapters on tracing your ancient ancestry and an introduction to our Study.
Book 2, which is subtitled Using Y-DNA, explains the essential nuts and bolts of Y-DNA testing and many of the techniques we use in analysing and presenting our members’ data. There are also chapters on the development of the Study and recalling our 2013 and 2017 ‘Gatherings’.
All proceeds will be reinvested in the McCarthy Surname Study (and, where appropriate, the R Z16526 and Subclades Project) funds for the furtherance of the study of M(a)cCarthy ancestry. To minimise printing costs and maximise royalties the paperback versions have been published in black and white. However this colour version of the double helix diagram on page 2 of Book 2 will better enable readers to follow the narrative.

The books may be purchased in local currency from Amazon publishing sites in USA, U.K., Canada, Australia, France, Brazil etc.. Book 1 is available here if purchasing in USA and here if purchasing from Amazon U.K, while Book 2 can be found here and here respectively.
Y-DNA Phylogenetic Trees
These trees show the genetic relationship between McCarthys in various branches of the overall Y (male)-tree of mankind illustrated in Fig. 1 below. The designations R-L21 Group A, B, C etc. are specific to the McCarthy Study and have no significance beyond this. Non-McCarthy Y-DNA testers are identified where their presence on trees may give clues as to McCarthy members’ origins or, in R-L21 Group B only, their own paternal ancestry lies in the eponymous Cárthach and / or the early McCarthy dynasties. The R-L21 Group B tree is a subset of that belonging to the R-Z16526 and Subclades Project, the whole of which is also provided here for convenience. This Z16526 tree thus traces the paternal ancestry of Cárthach.
Haplogroup E1b1b1 | SNP E–M35.1 (E1b1b1) | 2022 Feb 27 |
Haplogroup I1 | SNP I-M253 (I1) | 2022 Jun 09 |
Haplogroup I2a1 | SNP I-L470 (I2a1) | 2020 Sep 15 |
Haplogroup of R-U106 | SNP R-U106 | 2022 Jun 11 |
Haplogroup of R-U152 | SNP R-U152 | 2022 Jun 07 |
R-L21 Group A and Irish Type II (also on behalf of the R1b-CTS4466 Plus Project) | SNP R-A541 (Irish Type II) | 2022 Jun 27 |
Age Guide for R-L21 Group A and Irish Type II tree | Irish Type II Tree Mutation Block Age Table | 2022 Jun 26 |
R-L21 Group A | Temporarily withdrawn. Please use the above Irish Type II tree. | 2022 Apr 20 |
Haplogroup of R-Z16526 (on behalf of the R Z16526 and Subclades Project) | SNP R-Z16526 (leading to ZS4606) | 2022 Jun 29 |
R-L21 Group B (continuing from Sheet 3 of the R-Z16526 tree) | SNP R-ZS4606 | 2022 Jun 15 |
Age Guide for R-Z16526 tree (including McCarthy R-L21 Group B subset) | R-Z16526 Tree Mutation Block Age Table | 2022 Jun 26 |
R-L21 Group C | SNP R-M222 (Irish Type I) | 2021 Nov 19 |
R-L21 Group D | SNP R-L513 | 2021 Mar 05 |
R-L21 Group E | SNP R-Z255 | 2022 Jun 12 |
R-L21 Group F | SNP R-Z253 (including Irish Type III) | 2022 Jun 23 |
R-L21 Group G | SNP R-CTS3386 | 2020 Dec 28 |
R-L21 Groups H, I, J and N | SNPs R-FGC35995, R-Z251, R-S1051 and R-FGC10046 | 2020 Oct 16 |
R-L21 Groups K, L and P | SNPs R-DF5, R-3000 and R-Z16294 | 2022 Jun 14 |
Project Charts and Diagrams
Figure 1 | From Africa to McCarthy | 2020 Dec 30 |
Figure 2 | Development of principal McCarthy Septs | 2021 Jul 21 |
Figure 3 | Breakdown of McCarthys by haplogroup | 2022 Feb 25 |
Figure 4 | McCarthy Ancestral Haplotypes | 2020 Feb 09 |
Figure 4a | Y-DNA111 Mutation Frequencies | 2021 Jan 02 |
Figure 5 | McCarthy Sept names and Agnomina in use in the past few centuries | 2020 Sep 28 |
Pedigree Library
This is the new home for our members’ pedigrees, formally located on our WorldFamilies site (which was closed down by the site operators in May 2018).
McCarthy Surname Study Pedigree Library | 2018 Aug 13 |
Bibliography
Some book and manuscript references relating to McCarthy ancestry. Many are freely available to download.
Reading list | 2021 Jun 05 |
Scholarly Articles, Presentations etc.
The Rise of Meic Carthaig and the Political Geography of Desmumu. by Paul MacCotter | Journal of the Cork Historical and Archaeological Society, 2006 | 2006 |
The McCarthy family tree by R.C.McCarthy | The story of the MacCarthys of Ardcanaght. | 2012 |
MacCarthy Gathering Posters | Posters for the MacCarthy Gathering to celebrate ‘The Homecoming of the Daniel MacCarthy Glas Archive’, Dunmanway, Co. Cork, 26-28 May 2017. | 2017 May 31 |
McCarthy Surname Study Slide Show | Progress Report slide show for the MacCarthy Gathering, Dunmanway, Co. Cork, 26-28 May 2017. | 2017 May 28 |
Charles Mac Carthy in the Archives of Bilbao by Oisín Breatnach | Sources in the Archives of Bilbao giving a 17th/18th family history spanning four generations, with suspected MacCarthy Reagh origins (study ongoing). | 2017 Jul |
Freke Estate (Cork) Survey of 1787/88 curated by Pádraig Mac Cárthaigh | Link to Pádraig’s curation of the survey of the estate of Sir John Freke of Castle Freke, near Rosscarbery, Co Cork by the noted 18th-century Dublin land surveyor Thomas Sherrard. | 2019 Jun 05 |
Dunmanway Castle originally created by Fintan Mac Carthy | Link to Wikipedia article on one of two castles which were homes to the MacCarthy Norsa (an Fhorsa) family. | 2020 Jul |
Daniel Mac Carthy Glas originally created by Fintan Mac Carthy | Link to Wikipedia article on Daniel Mac Carthy Glas. | 2020 Aug |
Phylogenetic alignments with genealogies of descent from Ailill Ólom by N.D.McCarthy | A comparison of Irish Type II (McCarthy R-L21 Group A) phylogeny with ancient genealogical texts pertaining to first millennium ancestries. | 2021 Apr 14 |
Age guide dates for phylogenetic trees by N.D.McCarthy | Information concerning Mutation Block Age Tables provided in the Y-DNA Phylogenetic Trees section. | 2022 Jun 25 |