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R1b-CTS4466 Plus

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Display of Y-DNA Results

The Y-DNA Results page groups the participants according to their positive results for the SNPs associated with the Irish Type II haplotype wherever possible.  This is a fluid arrangement, since more SNPs are being identified regularly, through the extensive SNP tests, particularly the BIG Y and Y-Elite; and the groupings will change as we are confident that newly discovered SNPs appropriately separate into different subclades below CTS4466 and its equivalent SNPs. 

While the spreadsheet is usually up to date with the newest SNPs identified, this page may be a bit behind, so apologies if not all the branches are listed here yet and/or comments included.  If you see any errors, please let us know.

The CTS4466 Haplotree

The haplotree for CTS4466 continues to expand as more Big Y test results arrive.  It is getting very bushy, but a recent discovery of a high-level SNP separating the main branches further has been identified – FGC84010 – which makes the interpretation of the progression from the CTS4466 founder a bit more complex but also quite interesting.

For simplicity’s sake, here is a compressed tree with just the main branches:

































































































































































































































































A7751 is a small subclade at the top of the tree with typical Welsh surnames. 

S1115 begins to branch off as CTS4466 men begin to migrate.

A212 is geographically associated with Northern Ireland, Scotland and England, suggesting a migration north, then across the Irish Sea.

BY23591 is the second small subclade containing obvious Welsh surnames who 'stayed at home'.

FGC84010 is the recently identified major branching, with the vast majority of surnames found in it to be of Munster origin.

A541 beneath it splits into three significant subclades:

S1121 includes the majority of Eóganacht surnames across Munster, intermingled with earlier tribal groups, notably the Corca Laidhe and Corca Dhuibhne.

A1135 is a bit more broadly based, with Scottish and English surnames as well.

A151 seems to be a seafaring group, with surnames native to Kerry in the west to Waterford in the east of Munster, as well as a branch found up in Scotland and even Norway.

A663 is a brother branch to A541, notable for surnames found in the Seven Septs of Laois

Explanation of Groupings

The structure of the groups is based on the chart of SNPs displayed on the Background page, which matches Family Tree's CTS4466 haplotree (which all members  can see on their Y-DNA Haplotree & SNPs link).  We have used a combination of alpha/numeric lettering at the beginning of each group to keep them in order in the Results spreadsheet as new branches are identified and inserted.  Focusing on the last SNP listed identifies the branch.  We have the labels updated to match the new order of the Results spreadsheet (subject to another proofread).  If you note any inconsistencies, please let us know.  

(Note: A minus indicates negative for the SNP, a '/' indicates equivalents and a '>' indicates an SNP downstream of the previously listed SNP - a branch found in some but not all those positive for the SNP preceding it.  SNPs in italics are those branches we have identified that Family Tree have not yet acknowledged or by our comparing results from other vendors.)

Participants in each of these groups have not tested positive for any further downstream SNPs, though Big Y testers usually have a number of SNPs/variants which are found uniquely in an individual and considered 'private' SNPs.

The A? B?, B1?, C? etc groups are potential positives for the relevant SNPs, based on being a relatively close genetic distance to those who have tested positive for the SNPs and often sharing particular marker values.  Nigel's phylogenetic tree is also used for reference.  These are only possibilities, and further testing will be the only way to know for sure.

While this list may be a bit out of date, the Results spreadsheet is current.  We are also slowly widening our descriptions of the geographic trends and surnames in the various branches.

A1. A7751 > FGC43844

A1a.  A7751 > FGC43844 > FGC43847

A1a1. A7751 > FGC43844 > FGC43847 > FGC43838

       The current individuals in this branch are Jones or likely have Jones genetic heritage.  The names Jones, Morgan, Roberts are all 

       originally of Welsh origins.  Matching Sellers (two in the project) are from Wales as well.  At  this level, we could be looking at 

       the earliest beginnings of the Irish Type II haplotype. 

A2.  A7751 > A17979
       This is a surname-specific branch for Morgan.  Morgan is a Welsh personal name  The surname is found in Ireland, most

       numerous in Down and Armagh in the 16th century.  The current participants are from Armagh/Monaghan.

B1.  S1115 > A212 (A218 and/or downstream SNPs untested)

       S1115 is parallel to A7751, a very early division of CTS4466 itself.  The A212 branch is one of its branches.  An 18 at DYS481 separates it

       very distinctly from the other branches of CTS4466.  The participants tend to cluster in Northern Ireland, Scotland and the UK. 

       Kits in this group are only tested positive for A212 itself.

B1.  S1115 > A212 (A218+, downstream SNPs untested)

       Kits in this group have tested positive for both A212 and its assumed equivalent A218 but not tested for downstream SNPs.

B1.  S1115 > A212/A218 - negative downstream

        This BIG Y tester currently shares no other downstream SNPs with the other A212 BIG Y results.

B1a.  A212 > A206

       The first downstream branch of A212 identified, Scottish.

B1a1.  A212 > A206 > A208

        One individual so far, also Scottish.

B1b.  A212 > A6518

       A Walker surname-specific branch, across Ireland/England.  Walker is an old English word for 'fuller', and there
        is a matching Fuller in this branch.

B1c.  A212 > A7699

        Scottish and Irish.

B1c1. A212 > A7699 > A6525



B1c1a1.  A212 > A7699 > A6525 > A7756 > A9513

        A Thompson surname-specific branch, Ireland/UK.

B1c1a2. A212 > A7699 > A6525 > A7756 > FT19559

       NI and Scotland

B1c1b1. A212 > A7699 > A6525 > BY79430 > BY102663

       A Kelly, perhaps Ui Maine  

B1c2a. A212 > A7699 > A6526 > A6529

B1c2b1. A212 > A7699 > A6526 > BY186342 > BY200345

B1c2b2. A212 > A7699 > A6526 > BY186342 > FT61607


B1c3a.  A212 > A7699 > BY3535 > BY3862
        A Murphy surname-specific branch, Northern Ireland.


B1c3b. A212 > A7699 > BY3535 > BY222454

B1c4. A212 > A7699 > BY42760 

B1c4a. A212 > A7699 > BY42760 > BY53755

B1c4a1. A212 > A7699 > BY42760 > BY53755 > FT22615

B1c5. A212 > A7699 > BY66248

B1d.  A212 > A7648

        Stalker/Stoliker, probably Scottish


B2a. S1115 > BY23591 > BY23525

      S1115 had originally been considered an equivalent of CTS4466, until a BIG Y result showed otherwise.

      This is a surname-specific branch for Roberts, with a few Jones and a Sturgill added.  Indicative of Welsh origins.  

B2a1. BY23591 > BY23525 > BY12400

B2a1a1. BY23591 > BY23525 > BY12400 > BY137126 > BY90083

B2a1a2. BY23591 > BY23525 > BY12400 > BY137126 > BY218841

B2b.  BY23591 > BY23626

      A McCormick is currently alone in this group.  He has Ulster origins.

B3. S1115 > FGC84010

       The third major branch beneath S1115 with two further downstream branches - A541, the mot populous, and A663.

B3a. S1115 > FGC84010 > A541 (S1121-, A1135-, A151-)

B3a1. S1115 > FGC84010 > A541 > S1121
       This is a major SNP downstream of CTS4466 beneath A541, containing over half of those positive for A541.

B3a1a. S1115 > FGC84010 > A541 > S1121 > L270/Z16518/Z16521
       L270.2 was the first downstream subclade of CTS4466 found through the Geno 2.0 test, even prior to discovery of its upstream

       S1121.  While Sullivans dominate it, there are other surnames as well with no known relationship to Sullivan.  At least some are

       likely to have originally been from that clan before surnames were adopted.  There are a number of other SNPs equivalent to 

       L270.2.  Since it is found in more than one location on the haplotree, it has been superceded by Z16521 as a more appropriate 

       choice for the panels being offered by the testing companies.

B3a1a1. L270 > BY23396
      A McCarthy branch (a match not in the project yet).

B3a1a2. L270 > FT43021

B3a1a2a. L270 > FGC43021 > A1133

       This is a branch beneath L270, with mainly Sullivans and Keiths.

B3a1a2b. L270 > FGC43021 > BY3863

       This is a surname-specific branch of Teagues, with one Hart.

B3a1a2b1. L270 > FGC43021 > BY3863 > Y29014

      A further branch of Teagues.

B3a1a2b1a. L270 > FGC43021 > BY3863 > Y29014 > Y29013
       One more branch of Teagues.

B3a1a2c1. L270 > FGC43021 > PR2745 > BY16025

       A branch of Sullivans.

B3a1a2c2. L270 > FGC43021 > PR2745 > BY128975

       A branch of Sullivans.

B3a1a2d. L270 > FGC43021 > BY39363

B3a1a2d1. L270 > FGC43021 > BY39363 > BY39361

       McGillicuddy, a sept of O'Sullivan

B3a1a2d1a. L270 > FGC43021 > BY39363 > BY39361 > BY39364

       Another McGillicuddy

B3a1a2e1. L270 > FT43021 > FT82424 > BY29109

B3a1a2e2. L270 > FT43021 > FT82424 > BY29108


B3a1a3. L270 > FGC42465

       More Sullivans

B3a1b. S1115 > FGC84010 > A541 > S1121 > Z16252

       Z16252 defines another major subclade below S1121 with a number of further SNPs downstream.  There are several 

       instances of Welsh surnames present in this high level branch as well, further supporting the possibility that the subclade

       originated in Wales.

B3a1b1a.  Z16252 > A159 > BY2881

       A group of CTS4466 SNP Pack results discovered a number of participants at this level.

B3a1b1a1.  Z16252 > A159 > BY2881 > BY149

       A downstream branch of A159 and BY2881, also with a mix of surnames.

B3a1b1a1a.  Z16252 > A159 > BY2881 > BY149 > A923

      A variety of mainly Irish surnames.

B3a1b1a1a1.  Z16252 > A159 > BY2881 > BY149 > A923 > BY21613

B3a1b1a1a1a. Z16252 > A159 > BY2881 > BY149 > A923 > BY21613 > Y103372

B3a1b1a1a1a1. Z16252 > A159 > BY2881 > BY149 > A923 > BY21613 > Y103372 > FT29466

B3a1b1a1a2.  Z16252// A159 > BY2881 > BY149 > A923 > BY21614

      A surname-specific branch for Sheehan.

B3a1b1a1a2a.  Z16252 > A159 > BY2881 > BY149 > A923 > BY21614 > BY30544

B3a1b1a1a2a1.  Z16252 > A159 > BY2881 > BY149 > A923 > BY21614 > BY30546

B3a1b1a1a2a1a.  Z16252 > A159 > BY2881 > BY149 > A923 > BY21614 > BY30546 > BY34891

B3a1b1a1a2a1a1.  Z16252 > A159 > BY2881 > BY149 > A923 > BY21614 > BY30546 > BY34891 > BY119288

B3a1b1a1a2b. Z16252 > A159 > BY2881 > BY149 > A923 > BY21614 > FT18336

B3a1b1a1a2b1. Z16252 > A159 > BY2881 > BY149 > A923 > BY21614 > FT18336 > BY199869

B3a1b1a1a2b2. Z16252 > A159 > BY2881 > BY149 > A923 > BY21614 > FT18336 > FT20099

B3a1b1a1a3. Z16252 > A159 > BY2881 > BY149 > A923 > BY51516

B3a1b1a1a4. Z16252 > A159 > BY2881 > BY149 > A923 > Y108997

B3a1b1a1a5. Z16252 > A159 > BY2881 > BY149 > A923 > BY189083

B3a1b1a1b.  Z16252 > A159 > BY2881 > BY149 > Z17982/Z17983

      A new branch with Irish and a Scotsman at the moment. 

B3a1b1a1b1.  Z16252 > A159 > BY2881 > BY149 > Z17982 > A664        
       A branch with a variety of surnames.

B3a1b1a1b1a.  Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > A1511

      A surname-specific branch of McCartneys.

B3a1b1a1b1b.  Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > A7752

      An Irish branch.

B3a1b1a1b1b1. Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > A7752 > BY34893

B3a1b1a1b1b1a. Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > A7752 > BY34893 > BY69984

B3a1b1a1b1c. Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > A12015
      Another Irish branch.

B3a1b1a1b1c1.  Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > A12015 > BY23543

B3a1b1a1b1c1a. Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > A12015 > BY23543 > BY23443

B3a1b1a1b1d. Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > BY15517

      A surname-specific branch for Quirk/Kirks.

B3a1b1a1b1d1. Z16252 > A159 > BY2881 > BY149 > Z17982 > A664 > BY15517 > BY30547

B3a1b1a1b2. Z16252 > A159 > BY2881 > BY149 > Z17982 > BY21825

B3a1b1a1b2a1a. Z16252 > A159 > BY2881 > BY149 > Z17982 > BY21825 > BY34719 > BY102748 > BY72127

B3a1b1a1b2a2. Z16252 > A159 > BY2881 > BY149 > Z17982 > BY21825 > BY34719 > BY65170

B3a1b1a1c. Z16252 > A159 > BY2881 > BY149 > A6507

B3a1b1a1c1. Z16252 > A159 > BY2881 > BY149 > A6507 > A6508

       An Irish branch.

B3a1b1a1c2. Z16252 > A159 > BY2881 > BY149 > A6507 > S27124

      A branch of Cork men.

B3a1b1a1c2a. Z16252 > A159 > BY2881 > BY149 > A6507 > S27124 > BY23686

B3a1b1a1c2a1. Z16252 > A159 > BY2881 > BY149 > A6507 > S27124 > BY23686 > BY23843

B3a1b1a1d. Z16252 > A159 > BY2881 > BY149 > Z3006

B3a1b1a1d1. Z16252 > A159 > BY2881 > BY149 > Z3006 > BY23569

B3a1b1a2. Z16252 >A159 > BY2881 > A9185

      More Irishmen.

B3a1b1a2a. Z16252 > A159 > BY2881 > A9185 > A18874

B3a1b1b. Z16252 > A159 > F24356 

        A surname-specific branch for Roberson/Robinsons.

B3a1b1b1. Z16252 > A159 > F24356 > A20863

B3a1b2a.  Z16252 > Z18170 // A150

       A150 is an SNP subclade identified in early testing with an O'Mahony and Finns.

B3a1b2a1.  Z16252 > Z18170 > A150 > BY2877
      Another downstream level under A150.

B3a1b2a1a.  Z16252 > Z18170 > A150 > BY2877 > FGC11145
       FGC11145 and two equivalents define a subgroup beneath A150, including the surnames O Mahony and O'Reilly.

B3a1b2a1a1.  Z16252 > Z18170 > A150 > BY2877 > FGC11145 > FGC11152

B3a1b2a1b1.  Z16252 > Z18170 > A150 > BY2877 > BY2879 > A745
       To date, this group is found mainly in O Mahonys.  Both A745 and FGC11145 are identified by a 22 at DYS447.

B3a1b2a2. Z16252 > Z18170 > A150 > BY80113


B3a1b2b. Z16252 > Z18170 > FGC29280

       This is a subclade with various surnames - surely to be subdivided with more NGS testing.

B3a1b2b1a. Z16252 > Z18170 > FGC29280 > S1126 > A726

      This terminal branch also contains several different surnames.

B3a1b2b1a1. Z16252 > Z18170 > FGC29280 > S1126 > A726 > BY44567

B3a1b2b1a2. Z16252 > Z18170 > FGC29280 > S1126 > A726 > BY66777

B3a1b2b1a3a1. Z16252 > Z18170 > FGC29280 > S1126 > A726 > BY121005 > BY34724 > BY84873

B3a1b2b1a3a1a. Z16252 > Z18170 > FGC29280 > S1126 > A726 > BY121005 > BY34724 > BY84873 > BY127407

B3a1b2b1a3a2. Z16252 > Z18170 > FGC29280 > S1126 > A726 > BY121005 > BY34724 > FT19839

B3a1b2b1b. Z16252 > Z18170 > FGC29280 > S1126 > A542/S1129
      A subclade with a Hughey -  his 'cousins' another step downstream.

       A subclade with a number of surnames, some predicted but not tested yet.  Further NGS testing should identify separating

B3a1b2b1b1. Z16252 > Z18170 > FGC29280 > S1126 > A542/S1129 > FT41075

B3a1b2b1b2. Z16252 > Z18170 > FGC29280 > S1126 > A542/S1129 > BY120008

B3a1b2b1b3. Z16252 > Z18170 > FGC29280 > S1126 > A542/S1129 > S1112

B3a1b2b2. Z16252 > Z18170 > FGC29280 > BY3536

      A surname-specific branch for Ballard.

B3a1b2b3. Z16252 > Z18170 > FGC29280 > BY42407

B3a1b2b4.  Z16252 > Z18170 > FGC29280 > FGC29291

B3a1b2b4a.  Z16252 > Z18170 > FGC29280 > FGC29291 > FGC29286

B3a1b2b4a1.  Z16252 > Z18170 > FGC29280 > FGC29291 > FGC29286 > BY15516
      A further branch for Ferguson and a Thompson.

B3a1b3.  Z16252 > A9005

B3a1b3a. Z16252 > A9005 > A809

      Courtney/Cournane and Mahoney.

B3a1b3a1. Z16252 > A9005 > A809 > A806
       An Eóganacht Loch Lein Carroll surname.and Leahy.

B3a1b3a1a. Z16252 > A9005 > A809 > A806 > BY24758

       A surname-specific branch for Lee.

B3a1b3a1a1. Z16252 > A9005 > A809 > A806 > BY24758 > A2331

B3a1b3a2a1. Z16252 > A9005 > A809 > FT8178 > BY72807 > FT11102

B3a1b3a2a2. Z16252 > A9005 > A809 > FT8178 > BY72807 > FT56505

B3a1b3a2b. Z16252 > A9005 > A809 > FT8178 > BY47253

B3a1b3b. Z16252 > A9005 > A6516

      An English branch.

B3a1b3b1. Z16252 > A9005 > A6516 > A6511

B3a1b3c1. Z16252 > A9005 > FGC29068 > BY2880

B3a1b3c1a1. Z16252 > A9005 > FGC29068 >BY2880 > A804 > FGC29067

      The branch also has O'Donoghue and a Warren.

B3a1b3c1a1a. Z16252 > A9005 > FGC29068 >BY2880 > A804 > FGC29067 > FGC29071
       Parallel to A802, with a Kane and a McCarty.

B3a1b3c1a2a.  Z16252 > A9005 > FGC29068 >BY2880 > A804 > A802 > A803/BY3531

      A branch of O'Donoghues.

B3a1b3c1a2a1.  Z16252 > A9005 > FGC29068 >BY2880 > A804 > A802 > BY3531 > A914
      The branch of The O'Donoghue of the Glens.

B3a1b3c1a2a1a. Z16252 > A9005 > FGC29068 >BY2880 > A804 > A802 > BY3531 > A914 > BY121634

      The Glens direct line with a known distant cousin descended from a brother of The Glens in the 1600s

B3a1b3c1a2a2.  Z16252 > A9005 > FGC29068 >BY2880 > A804 > A802 > BY3531 > BY206958

B3a1b3c1b. Z16252 > A9005 > FGC29068 >BY2880 > FGC17180

B3a1b3c1b1a. Z16252 > A9005 > FGC29068 >BY2880 > FGC17180 > A2224 > A2221


B3a1b3c1b1a1. Z16252 > A9005 > FGC29068 >BY2880 > FGC17180 > A2224 > A2221 > A6464

      Moriarty and others

B3a1b3c1b1b. Z16252 > A9005 > FGC29068 > BY2880 > FGC17180 > A2224 > BY201596

B3a2. S1115 > FGC84010 > A541 > A1135/A1136

B3a2a.  A1135 > A2427

       A single Morgan, probable Welsh.

B3a2a1.  A1135 > A2427 > BY21618
       English surnames. 

B3a2b.  A1135 > A9426

      A branch of Welsh Abers.

B3a2c1.  A1135 > A11844 > A12525
      A further sub-branch of Hickey.

B3a2c2.  A1135 > A11844 > BY32462

B3a2c2a.  A1135 > A11844 > BY32462 > BY32460

B3a2d.  A1135 > BY19775
       An Irish branch.

B3a2d1.  A1135 > BY19775 > A956

       A single Scotsman.

B3a2d1a1.  A1135 > BY19775 > A956 > A2288 > BY19776

B3a2d1a2a.  A1135 > BY19775 > A956 > A2288 > A5313 > A5312

B3a2d1a2a1.  A1135 > BY19775 > A956 > A2288 > A5313 > A5312 > A8748
         A surname-specific branch of Bryan.

B3a2d1a2a1a.  A1135 > BY19775 > A956 > A2288 > A5313 > A5312 > A8748 > A7753

      A further downstream branch of Bryan.

B3a2d1a2a2.  A1135 > BY19775 > A956 > A2288 > A5313 > A5312 > BY34895

B3a2d1b.  A1135 > BY19775 > A956 > A7754

       Contains a Lynch and Lindsey.  There are numerous septs of Lynch, with Lindsey suggested as a variant form of the name.

       Sharing a terminal SNP supports this to be accurate. Possibly Dál gCais.

B3a2e. A1135 > FT7592

B3a2e1.  A1135 > FT7592 > A195
       This is a second major SNP downstream of CTS4466 under A541 and parallel to S1121.

B3a2e1a1.  A1135 > FT7592 > A195 > A761 > A88
       A variety of Irish surnames, mainly Creameans/Cummings.

B3a2e1a1a.  A1135 > FT7592 > A195 > A761 > A88 > Z16258/Z16259

       Another variety of Irish surnames.

B3a2e1a1a1. A1135 > FT7592 > A195 > A761 > A88 > Z16259 > BY2876

B3a2e1a1a1a.  A1135 > FT7592 > A195 > A761 > A88 > Z16259 > BY2876 > ZS4590

      A surname-specific branch for McCarthy.

B3a2e1a1a1b.  A1135 > FT7592 > A195 > A761 > A88 > Z16259 > BY2876 > A1333
       A surname-specific branch for Riggin/Ragan.

B3a2e1a1a1b1. A1135 > FT7592 > A195 > A761 > A88 > Z16259 > BY2876 > A1333 > Y47157

B3a2e1a1a1b2. A1135 > A195 > A761 > A88 > Z16259 > BY2876 > A1333 > BY24169

B3a2e1a1a2a.  A1135 > FT7592 > A195 > A761 > A88 > Z16259 > A2220 > A2219
      A McCarthy(Broagh).

B3a2e1a1a2a1.  A1135 > FT7592 > A195 > A761 > A88 > Z16259 > A2220 > A2219 > A2294

       A surname-specific branch of Donovans.

B3a2e1a1a2a2.  A1135 > FT7592 > A195 > A761 > A88 > Z16259 > A2220 > A2219 > A12017
       A further branch of Donovans.

B3a2e1a1a2b.  A1135 > FT7592 > A195 > A761 > A88 > Z16259 > A2220 > A7755
      A surname-specific branch of Hayes.

B3a2e1a1a2b1. A1135 > FT7592 > A195 > A761 > A88 > Z16259 > A2220 > A7755 > BY70308

B3a2e1a1a3. A1135 > FT7592 > A195 > A761 > A88 > Z16259 > A10727

B3a2e1a1a3a. A1135 > FT7592 > A195 >A761 > A88 > Z16259 > A10727 > BY42849

B3a2e1a1a4. A1135 > FT7592 > A195 > A761 > A88 > Z16259 > FT85796

B3a2e1a1a5. A1135 > FT7592 > A195 > A761 > A88 > Z16259 > BY104765

B3a2e1a1b.  A1135 > FT7592 > A195 > A761 > A88 > A7660/A12223

      An Irish branch, mainly Crowleys.

B3a2e1a1b1. A1135 > FT7592 > A195 > A761 > A88 > A7660 > BY106347

B3a2e1a1b2. A1135 > FT7592 > A195 > A761 > A88 > A7660 > BY203429

B3a2e1a1c. A1135 > FT7592 > A195 > A761 > A88 > FT76192

B3a2e1a1c1. A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89

       An Irish branch.

B3a2e1a1c1a.  A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > A155
       A variety of surnames, Irish, Scottish and Norman(?)

B3a2e1a1c1a1.  A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > A155 > A156

       A surname-specific branch of McDonald.

B3a2e1a1c1a2. A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > A155 > BY34898

B3a2e1a1c1a2a1. A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > A155 > BY34898 > FT111304 >BY156940

B3a2e1a1c1a2a1a. A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > A155 > BY34898 > FT111304 > BY156940 > BY184272

B3a2e1a1c1a3. A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > A155 > BY97073

B3a2e1a1c1b.  A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > BY15518
      A surname-specific branch of Irwin/Erwin.

B3a2e1a1c1b1. A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > BY15518 > BY161234

B3a2e1a1c1b1a. A1135 > FT7592 > A195 > A761 > A88 > FT76192 > A89 > BY15518 > BY161234 > BY163142

B3a2e1a1d. A1135 > FT7592 > A195 > A761 > A88 > BY23574

B3a2e1a1d1. A1135 > FT7592 > A195 > A761 > A88 > BY23574 > BY208692


B3a2e1a2a1.  A1135 > FT7592 > A195 > A761 > Z16254 > A154 > A153 

      A variety of Irish and English surnames.

B3a2e1a2a1a.  A1135 > FT7592 > A195 > A761 > Z16254 > A154 > A153 > A474

      An Irish branch.

B3a2e1a2a1b.  A1135 > FT7592 > A195 > A761 > Z16254 >A154 > A153 > BY11841

      A surname-specific branch for Glennon.

B3a2e1a2a2. A1135 > FT7592 > A195 > A761 > Z16254 > A154 > BY55890

B3a2e1a2b.  A1135 > FT7592 > A195 > A761 > Z16254 >A1338

      Another Irish branch.

B3a2e1a2b1.  A1135 > FT7592 > A195 > A761 > Z16254 > A1338 > A1336
      A Murray and a Hunter so far.

B3a2e1a3.  A1135 > FT7592 > A195 > A761 > A12590

      A Gilliam.

B3a2e1a3a1. A1135 > FT7592 > A195 > A761 > A12590 > FT60126 > A12589


B3a2e1b.  A1135 > FT7592 > A195 > A10641

      A McAuliffe.

B3a3. S1115 > FGC84010 > A541 > A151

B3a3a. A151 > BY139

B3a3a1a.  A151 > BY139 > BY141 > BY140

        This branch contains men of Norwegian descent.  (Surnames are not patrilineal in Norway.)  It is likely that these gentlemen
       descend from the same ancestor, perhaps a sailor/merchant/slave who came to Norway, possibly a millennium or more ago.

B3a3a1b. A151 > BY139 > BY141 > BY42721

B3a3a1b1. A151 > BY139 > BY141 > BY42721 > BY77015

B3a3a2.  A151 > BY139 > A9865
       This is an Irish-born subclade.

B3a3a2a.  A151 > BY139 > A9865 > A12087

       A single kit of Northern Irish ancestry.

B3a3a2a1.  A151 > BY139 > A9865 > A12087 > A12148
       Also Northern Irish/Scottish ancestry.

B3a3a2b. A151 > BY139 > A9865 > BY43350

B3a3a3. A151 > BY139 > BY65689

B3a3a3a. A151 > BY139 > BY65689 > BY212618

B3a3a3a1. A151 > BY139 > BY65689 > BY212618 > BY153186

B3a3b.  A151 > B42

       Another branch under A151, one kit, probably a German surname.

B3a3b1.  A151 > B42 > A7659

        An Irish O'Connell branch, these individuals found in Waterford/Tipperary.

B3a3b1a.  A151 > B42 > A7659 > A7654

       The main Kerry branch of O'Connells.

B3a3b1b. A151 > B42 > A7659 > FT47674

B3a3c1.  A151 > A743

       A single Morrissey.

B3a3c1a.  A151 > A743 > FGC29773

       A branch of Scottish MacAulays.

B3a3c1a1.  A151 > A743 > FGC29773 > FGC29771

       More MacAulays.

B3a3c1a1a.  A151 > A743 > FGC29773 > FGC29771 > F3189

      More MacAulays.

B3a3c1a1b. A151 > A743 > FGC29773 > FGC29771 > BY15520

       Yet more MacAulays

B3a3c1a1b1.  A151 > A743 > FGC29773 > FGC29771 > BY15520 > BY15519

      One last MacAulay branch.      

B3a3c1a1c.  A151 > A743 > FGC29773 > FGC29771 > BY51215

B3a3c1a1d.  A151 > A743 > FGC29773 > FGC29771 > FGC29774

B3a3d1. A151 > FT11185 > A714
        A second subclade beneath A151 with a variety of surnames, Irish/Scottish/English.

B3a3d1a1. A151 > FT11185 > A714 > A715 > FGC23796

       A branch with basically English surnames.

B3a3d1a2. A151 > FT11185 > A714 > A715 > FGC30535

B3a3d1a2a. A151 > FT11185 > A714 > A715 > FGC30535 > FGC30538

B3a3d1a2b. A151 > FT11185 > A714 > A715 > FGC30535 > BY77371

B3a3d1a2b1. A151 > FT11185 > A714 > A715 > FGC30535 > BY77371 > BY108746

B3a3d1b. A151 > FT11185 > A714 > BY186440

B3a3d1c. A151 > FT11185 > A714 > BY111005

B3a3d1c1. A151 > FT11485 > A714 > BY111005 > FT20917

B3a3d1c1a. A151 > FT11185 > A714 > BY111005 > FT20917> BY197966

B3a3d2. A151 > FT11485 > FT74196

B3a3d2a.  A151 > FT11485 > FT74196 > BY21620

       The newest branch of A151, Richie/Pearson.

B3a3d2a1. A151 > FT11485 > FT74196 > BY21620 > BY21619

B3a3d2a1a. A151 > FT11485 > FT74196 > BY21620 > BY21619 > BY34899

B3a3e1. A151 > FT83818 > BY110712

B3b. S1115 > FGC48010 > A663

       A third branch parallel to A541, directly downstream of CTS4466.  It contains two distinctly different haplotypes, suggesting it
       is of some age. They all have 14-30 at DYS389 and most have a 14 at DYS442 and 15 at DYS497.  Recent testing has begun to
       split it. 

B3b1.  A663 > A2289

       A branch under A663, A2289 and three equivalents separates one of the haplotypes present in A663, identified mainly by a
      12-15 at DYS385 and 15-15-16-17 at DYS464.  It contains surnames of the Seven Septs of Laois

B3b1a. A663 > A2289 > BY81788

B3b1a1. A663 > A2289 > BY81788 > FT57712

B3b1a1a. A663 > A2289 > BY81788 > FT57712 > FT57428

B3b1b. A663 > A2289 > FT33173

B3b1b1. A663 > A2289 > FT33173 > FT33326

B3b1b1a. A663 > A2289 > FT33173 > FT33326 > A2291

      McBee and Punkett are the surnames currently positive for this SNP.

B3b2a.  A663 > BY24324 > A5595

       A surname-specific branch for Butler.

B3b2b. A663 > BY24324 > FT17964

B3b2b1. A663 > BY24324 > FT17964 > BY93490

B3b2b1a. A663 > BY24324 > FT17964 > BY93490 > Y34442 

B3b2b1a1. A663 > BY24324 > FT17964 > BY93490 > Y34442 > BY69735

Has Tested Positive for CTS4466

        This includes anyone who has tested positive for CTS4466 but no further SNPs downstream

Early Findings
Our database is increasing as new members join and we continue to recruit participants whose haplotypes match the Irish Type II modal.  While we still have a large number of participants who have not yet tested for SNPs, but this is slowly dwindling.

For those participants with less than 67 markers tested, upgrading to the 67 marker level of STR testing (or ideally the full 111 marker level) is a way to help us develop and refine these categories and improve our picture of the CTS4466 haplogroup. There are markers in the 68-111 panels that are particularly useful in identifying clusters of individuals. Upgrading will also benefit individual members in their personal genealogy quest by helping to more accurately identify potential relatives, and it would make it easier for us to suggest specific SNP tests in the future. If any participants are interested in SNP testing now, please contact Elizabeth for recommendations before deciding which test to choose.  The R1b-CTS4466 Plus SNP Pack is by now out of date for most subclades.

Updates on the Extensive Y-DNA SNP Testing in the Project



By now, we have well over 100 BIG Y results, and more keep coming in. There is a huge amount of data to review. While some positive SNPs display on the Y-DNA SNP page, it does not include them all. There is a downloadable VCF file available to each participant with the raw data from their test; and Family Tree is also providing a very extensive .BAM file that contains even more data than available in the VCF folder.  Since Family Tree have reloaded the data for all existing BIG Y testers in 2017, the BAMs aren't available right now.  We are asking that everyone with results share the VCF link with us, since it contains much useful information to clarify what is shown in the participants’ personal pages.  All testers receive instructions on how to send us this folder.

Debbie Kennett’s blog provides some interesting insights into the test:

Roberta Estes has also prepared an informative blog post:

For those of you who have taken the BIG Y test, Family Tree has a tutorial at: and a webinar at  The webinar is labeled 'FTDNA Product Launch Webinar:  Getting to Know  BIG Y Results'.  Clicking on it, you will be asked to register and you will immediately be transferred to the link to see it.

Maurice Gleeson has a very worthwhile blog, DNA and Family Tree Research -

Alex Williamson, one of the gurus of the genetic genealogy community, has a very comprehensive The Big Tree at that analyses all the BIG Y results to which he has access.  He is not currently updating it, but our participants who tested earlier and submitted their data can be seen individually on the link P312>L21>DF13>FGC11134 .  If you click onto a specific SNP, you will often be directed to a second page with additional information.  Family Tree have adopted Alex's format (with his permission) for their Block Tree link.

CTS4466 SNP Pack

The CTS4466 SNP Pack was introduced by Family Tree in early 2015.  It tested for all known branches of the CTS4466 tree at that time.  Its results are incorporated into the participants' Haplotree & SNPs link and display the terminal SNP in the Badges box on the left of their home page.  The Pack was updated to include newly identified branches in 2017, but by now the number of branches has far exceeded the capacity of the Pack testing.  We are waiting for Family Tree to develop a better method to capture all the known branches of our subclade.  The Pack can confirm to which branch a participant belongs, but we recommend you check with an Administrator before ordering it, since it might not contain all the branches to which a particular kit may belong, reducing its usefulness.  New branches can only be identified through the BIG Y test.

First Subclade of CTS4466 - L270.2

The first formal subclade under CTS4466 that was identified is defined by the SNP L270.  Since this SNP was previously discovered in haplogroup J, ISOGG has agreed with our proposal that it be recognised as L270.2.  At the moment, the subclade is dominated by Sullivans, but other surnames also feature, some genealogically related to Sullivans and others with no apparent connection.  Just recently, another SNP downstream of L270.2 has been identified - A1133.  It is now available for individual testing as well as L270.

Nigel has created a phylogenetic tree for the Irish Type II members of the McCarthy Surname Study, including kits of other surnames with similar haplotypes.  The chart includes a branching suggesting the possible structure of this L270 subclade. Those kits which have tested positive for the SNP are highlighted orange, while kits tested negative are highlighted tan. The chart can be found in the Files section of our Forum.

The L270 genetic signature that differentiates it from the overall Irish Type II modal includes key STR mutations at four markers:  DYS481 (up from 22 to 23 or more) in panel 4b, DYS710 (down from 35 to 34 or less) in panel 5a, DYS533 (down from 13 to 12 or less) in panel 5b and DYS552 (up from 24 to 25) in panel 5d. As we see more results, this may change somewhat, but these values are good indicators of those likely to prove positive for the SNP. To date, the chart has correctly predicted both positive and negative results. It should be noted, however, that this is a "best guess" tree and liable to change as more data becomes available.

S1121 & Other Significant SNPs

S1121 was first found in the Chromo2 test, and the BIG Y test also includes it.  It defines the largest subclade beneath CTS4466.  The BIG Y in particular has provided us with a number of other SNPs that are common 1) to all Irish Type II participants, 2) to certain clusters of participants, even surname-specific branches, and 3) individual to each participant.  By now, we have expanded the tree considerably through the numerous BIG Y tests taken by project members, and more branches beneath these continue to be discovered as more BIG Y test results come in.  In addition to A541 which is upstream of S1121, A195 and A151, as well as A212 and A663 that are parallel to A541, we have two branches upstream of A541 as well - S1115 and A7751.  The hierarchical tree on the Background page lists all the current ones and the subclades further downstream, and we have a chart available on the Forum in the Files section or at  As our analysis continues, we update everyone with our ongoing conclusions, posting the data in files available on the Forum or through dropbox links on the website. 

We intend to provide further analysis of the different branches that have been identified in the near future.


The questions in the minds of everyone who is interested in the Irish Type II haplotype are where did it originate and how is it related to the ancient Eóganacht tribes who ruled Munster unopposed for over 500 years, from about 500 to 1000 AD.

At the beginning of 2012, the Munster Irish Project - - was initiated to study the genetic heritage of the province.  This was prior to the discovery of the CTS4466 SNP that has come to be associated with the Irish Type II haplotype.  Its Y-DNA Results table is grouped by the tribes to which the surnames belong (according to the ancient genealogical tracts) regardless of their haplotype.  It was apparent from the beginning that the Irish Type II haplotype is found throughout Munster; and while almost all of the names associated with the Eóganacht do have a significant amount of Irish Type II in their lineages, it is not limited to those surnames.  The Deisi Mumhan and the Eli, whose territories are both at the edge of the ancient Munster territories, are the only tribes whose associated surnames don't show any Irish Type II (though the Deisi may).

The degree of presence of Irish Type II in historically older tribes, most notably the Corca Laidhe and the Corca Dhuibhne, cannot be reasonably attributed merely to NPEs, adoptions, war (and the accompanying rape/pillage), etc.  It suggests that the progenitor from whom all “Irish Type II” peoples flourished significantly predated the emergence of the Eóganacht as a ruling force in Munster.  What also needs to be considered is the fact that a number of subclades/clusters of CTS4466 contain individuals whose family origins are found in different geographical areas - in the north of Ireland, Scotland, parts of England and the Scandinavian countries, and even a few other continentals.  Travel by sea and the ease of trade that the coastal routes afforded between all these areas, not to mention the active slave trade (Dublin was a noted Viking slave market that existed from the 9th into the 12th centuries) no doubt played a part in the distribution of the Irish Type II as well as all other Irish haplotypes.

The mythical ancestor of the Eóganacht, Eógan Mór, is supposed to have descended from the Milesians, whose arrival in Ireland forms the closing chapter to the ancient Book of Invasions (Leabhar Gabalah Éireann) an 11th century compilation of earlier texts which identifies this event as the final invasion where the Milesians land in Kenmare Bay and bring the Gaelic culture to Ireland.  The sons of Mil, or Miles Espania (the Spanish soldier) were supposed to have invaded Ireland from Spain.  Some of the early scholars suggested dates as early as 1700 BC based on the Book of Invasions.  This genesis myth was taken quite seriously during the period of the Celtic Revival, but there are few who give it much credence now.

While the degree of DNA testing done in men of recent Iberian origin is currently not as extensive as could be wished, there is no evidence of the Irish Type II haplotype in this region, so that it would currently be difficult to support an Iberian origin for the Eóganacht.  If there was a Milesian invasion with male progeny surviving to this day, it's quite doubtful they were Irish Type II.

In any case, to consider the relevance of the Irish Type II haplotype to the genealogy of the Eóganacht, a typical pedigree tree of the various Eóganacht septs has been created based on ancient genealogies and overlaid with the CTS4466 tree with an indication where appropriate of some participants with Eóganacht surnames who have tested to their current terminal SNP.  It has produced some interesting results.  The chart can be downloaded from or found in the Files section of the Forum.  There are explanatory notes included in the chart, but we will add a few remarks here as well.

The following key considerations form the basis of this tree:

  1. Extensive review of pertinent literature by members of The O'Donoghue Society has led to the conclusion that the ancestry of O'Donoghue of the Glens lies in the Co. Tipperary/Cashel O'Donoghues (who are sometimes ignored in genealogical tracts) and not the Eóganacht Raithlind, as suggested in some ancient annals.

  2. Similar research indicates that the O’Donoghue Mór lineage is not Irish Type II.  (See  Y-DNA evidence also suggests that the McCarthy Mٕór lineage is not Irish Type II either. (See “Summary of Findings” at  The phylogenealogy of both is indicated on the far left of the chart).

There are a number of notes on the chart itself to clarify the arrangement of the SNPs and the Eóganacht surnames included.  The order of the SNP hierarchy (each highlighted in yellow) does not always coincide with the structure of the Eóganacht genealogy, requiring a number of lines and arrows pointing to the reality of the SNP tree with the purported interrelatedness of the various septs of the Eóganacht.

All the Eóganacht surnames are found downstream of A541.  On the left, there is the obvious branch of L270.2, dominated by the O'Sullivans and including McGill(icuddy), consistent with ancient genealogies, but the other main Eóganacht Cashel surnames of McCarthy and O'Donoghue do not share that SNP except for 2% of Irish Type II McCarthys, which is not considered significant enough a proportion to validate such a genealogy.  Instead we show four different surviving lineages attributable to the Eóganacht Cashel.

While we are able to present O’Keefe’s position in a manner consistent with the ancient genealogies, more testing of O’Keeffes is required to confirm this. Note also that many other (mostly Munster) surnames are associated with the O’Keeffe SNP A159.

Almost all other Eóganacht surnames are found under Z16251 and A1135.  Alongside these are pockets of surnames that have no hint of Munster or even Irish origin, often with more diversified haplotypes and/or on earlier branches of the tree.  In some instances, these can be explained by permanent migration out of Munster and/or across the Irish Sea.  However, there is not always an apparent rationalization for non-Eóganacht surnames carrying the same SNPs as Eóganacht surnames.

Rev O’Keeffe’s Book of Munster, a 1703 summary of earlier sources of greater or lesser renown, does list a large number of Munster surnames as derived from the tribal progeny of the Eóganacht Raithlind; it remains to be seen whether such claims can be validated. A number of these, such as O’Callaghan, O’Connelly, O’Donoghue and O’Leary have other independent origins in Munster and often in the rest of Ireland.

Some historians consider the Eóganacht Loch Lein to be the original Eóganacht, from which all other septs evolved, migrating eastwards into greater Munster.  There is so far no evidence to support an early independent Eóganacht Loch Lein lineage. The two Moriartys and one Carroll representing this sept and who have deep clade tested all show a relatively late first millennium ancestry shared with O’Donoghue of the Glens, which is unexpected and puzzling.  However, others of these surnames may be found in different areas of the tree, so more testing is required to draw reliable conclusions on the origins of this foundation sept.

The Uí Liathan and Uí Fidgeinti are also tribes with lineages attributed to Eóganacht origins.  As with Eóganacht Raithlind, further surnames purporting to be associated with these, such as Gleason and O’Corráin, not represented in our project at the time of the tree construction, are omitted for clarity for the time being.  Most Donovans and Collinses, the modern day flag bearers of Uí Fidgeinti origins who are Irish Type II, are found beneath Z16259 alongside others with compatible Thomond origins such as O’Hourihane, O’Brien and O’Regan. (O’Briens in Thomond and McCarthys in Desmond were the most powerful families in mediaeval Munster so it is not unexpected that many will have taken these names through “clan affiliation” rather than a paternal genetic descent.)  However, the surnames Donovan and Collins may also be argued as having Corca Laidhe origins, and the identification of some Z16259 O’Driscolls hint at this as an alternative origin. The situation is further confused by the historical record of a migration of Uí Fidgeinti southwards from their Co. Limerick homelands into territories occupied by Corca Laidhe in 1178 and beyond.  (It could, however, be argued that the O’Driscoll name might then have also been assumed by some through affiliation to the dominant “clan” of the area, since I-P37 is the most prominent haplogroup of the O'Driscolls.)

Clearly, from the range of surnames and phylogenetic tree structure under A1135, either Fiachu Fidgenid, the founder, had a far greater progeny than has previously been recognised or the Uí Fidgeinti were just one branch of a major sublineage.  The tree currently suggests the latter. There are many names in the tree structure between A1135 and Z16259 suggestive of locations beyond Munster, although a few, such as Griffin, O’Hearn, Irwin and Allen, further support a Thomond association.  Since Aine is very close to Emly, a 10th / 11th century focal point of the later McCarthy dynasty, we are also investigating possible Eóganacht Aine connections with surnames other than Kerwick/Kirby, represented to date by just one participant who shares ancestry with one of the two significant Daly groups.

The A151 branches are listed at top right.  Subject to further testing now underway, at present it comprises 1) two distinct single surname branches: O'Connell (of Dingle Bay) and MacAulay (of the Outer Hebrides), 2) branches with a strong Scandinavian presence and 3) a subclade of predominantly English, Welsh and Scottish names but including the only other Irish name, one of two Irish Type II Brazils. (The other is in the Z16254 subclade under A1135, but neither corresponds with a possible O'Breassail sept as indicated in the historical Eóganacht genealogies).  There have been several interesting discussions on the Forum about these families. You need to join the Forum ( to view them, and we hope more of you will join to see these discussions as well as the other data available there.

The A212 and A663 branches are parallel with A541 and may pre-date the tree provided. They do not feature Eóganacht surnames and are geographically associated with Northern Ireland, Scotland and England.  This does not preclude a Munster origin as they may have developed in the progeny of migrants who had travelled northwards/eastwards across the Irish Sea.  It's always possible that they could be indicative of the location of the common ancestry of all on the subject tree, though a migration south does not fit well with the early historical information available to us. 

There is the promising potential of Wales as a source from whence the early Irish Type II ancestors migrated to Munster.  The A1 and B2a groups in the Results spreadsheet contain kits dominated by Welsh surnames.  They are all in branches at the 'top of the tree', being the early mutations after CTS4466 and its equivalents.  Even branches of FGC11134, the SNP upstream of CTS4466 on the L21 haplotree, contain Welsh surnames, giving further credence to the possibility of a Welsh origin.  The A212 and A663 branches may have originated from a Welsh source traveling north and then across to Ireland from there.  There have been lively discussions of origins on our Forum.

It is apparent that the validated Y-DNA hierarchy of the Irish Type II tree does not coincide with the Eóganacht genealogies in a straightforward manner.  The DNA is real.  The ancient tracts, not only about the Eóganacht but all the other tribes present in ancient Ireland, are notorious for being conflated, inflated, if not fabricated.  However, that does not mean that they are entirely invented, and the old adage, 'where there is smoke there is fire' could apply here.  Our attempts at correlating the Y-DNA and the ancient annals/genealogies do not reconcile the apparent differences and conflicts, and it's possible they never will, but there is a degree of structure to what we have presented in the chart

The phylogenetic tree from A541 downward supports a concept of one, perhaps early first millennium common ancestor whose progeny is represented in many Eóganacht tribes.  Within Irish Type II, surnames purporting derivation from these tribes are predominantly found in the S1121 subclade of A541, suggesting that if there is a figurehead to this family, S1121 would have been his terminal SNP.  However, in view of the considerable other surnames present in those A541 branches, even taking  into account migrations into and out of Munster, NPEs and surnames gained by clan affiliation, it is problematic to suggest that the common ancestor can be claimed by the descendants of those Eóganacht tribes alone.  Some inter-relationships within the historical genealogies may be viable, but others would need adjustment to be compatible with the genetic data.

The progenitor of the Irish Type II could have been a recent ancestor of the semi-mythical Eoghan Mór, with the S1121 and A1135 subclades of A541 appearing in his progeny, but then again that progenitor might be someone even more ancient. With the relative prevalence of Irish Type II in the Corca Laidhe tribes and their territorial predominance throughout much of Munster prior to their overthrow by the Eóganacht, who disposed them of most of their territory, it's not impossible that the Irish Type II originated within these earlier tribes.  We need to be open minded about the possibilities.  At the moment, Wales seems to be in the mix in a significant way.

The chart is not meant to be all inclusive at this point and it will be an ongoing project.  We anticipate expanding it to include additional data regularly.  Along with that, our challenge is to try and determine the relative validity of the various ancient Irish tracts and other historical documents that chart the history of all those who are CTS4466/Irish Type II, both in Ireland and wherever their wanderings took them, and discover how they are all related.  No easy task, but we look forward to updating this study as more NGS and CTS4466 Panel data becomes available and we broaden our knowledge.


There is an understandable interest in how old CTS4466 is.  We must first recognize that the TMRCA is only the time to the most recent common ancestor - not necessarily the original one.  The man with the initial SNP that defines the subclade represented by CTS4466 and its equivalents almost surely lived much earlier, perhaps by even 1500 years or more, due to a bottleneck evidenced by a significant number of equivalent SNPs to CTS4466 itself, implying a long period in which the lineage survived by a thread, before S1115 and A7751 occurred.  There were probably more branches in the lineage at one time, but any offshoots from the numerous equivalent SNPs or indeed other branches of CTS4466 itself, based on our current data, have died out.  Hence, the common ancestor to whom we try to estimate a TMRCA period is an embodiment of a complex lineage going back that we will almost certainly never be able to completely decipher.  What we can hope for is continued discoveries of further branches as we receive more BIG Y results for not only the CTS4466+ participants in our project, but also the directly upstream SNPs of FGC11134+ but CTS4466- participants.  These upstream SNPs may also provide clues of their own to the origins of CTS4466.


There are various methods of calculating TMRCA - based on the number of SNPs separating different subclades, the number of mutations present in the dataset chosen, STR diversity, etc.; and different dates have been calculated, depending on mutation rates used, counting of mutations and/or number of SNPs between branches, percent of probability considered, and factors for bottlenecks, back mutations, etc. taken into account, which are variables that can never be known for sure.  While the results are sometimes similar between different citizen scientists and more commercial statisticians studying DNA, even professional statisticians have to admit that there can be no certainty in the level of accuracy any of these methods provide, and it's possible there could be significant underestimations.

It had been suggested that the ancestor of the Irish Type II may have lived sometime in the first half of the first millennium A.D, but increased data has pushed that possibility back a bit.  You can find current estimated TMRCAs for most of the branches of CTS4466 at Alex Williamson’s Big Tree at  Click on the particular SNP you are interested in and you’ll get a second page, which many include an Age Analysis at the bottom of the page.  For CTS4466, Alex (using Iain McDonald's calculation method) suggests 'the median age of this block is 2316.5 YBP (367 BC). The 95%confidence interval is 854 BC to 17 AD'.

Nigel McCarthy completed a paper in 2016, AN IRISH TYPE II TIMELINE EXPLORED THROUGH UÍ CHAIRPRI AEBDA, which he describes as 'a new approach to determination of mutation rates suitable for constructing a timeline with defined boundary conditions, applied to the subclade of Z16259. Article includes discussion of Uí Fhidgeinti origins.  It can be found in the Files section of the R1b-CTS4466 Plus Project Forum under the title 'Mutation rates for  Z16259 timeline'.  It can also be downloaded from

Ancient Irish DNA

In addition to the citizen scientists who are studying the modern DNA of all those who have tested, the professional scientists and academics have for some years now been gathering data from ancient bones.  There is a growing database of the DNA of ancient specimens all around the world; and there is a paper just published - Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome - by a collaboration between Smurfit Institute of Genetics, Trinity College, and School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, headed by Professor Dan Bradley, in which the DNA of four prehistoric individuals has been tested for the first time.  It includes a Neolithic woman from a megalithic burial at Ballynahatty, Co. Down, estimated to be 3343–3020 BC based on associated artefacts and three Bronze Age males from Rathlin Island off the coast of Co. Antrim estimated to be of an age of 2026–1534 BC.  The paper can be downloaded for free at

The female was determined to be of predominantly Near Eastern origin, indicating there was an influx of early farmers to the island during the Neolithic era.  Her haplogroup was HV0.  The males had a substantial heritage of Bronze Age herders going back to the Pontic Steppes.  One of the males was tested to DF21>Z30233. 

This is not the forum to go into more detail of the paper and its results, but anyone interested can access the paper and its accompanying appendix SI Appendix, Section S1 - listed on page 1 of the document.

Maybe someday Y-DNA testing of other skeletal remains which can be reliably dated by other means will give us an indication of the earliest occurrence of CTS4466 in Munster or elsewhere, if the trail leads us to a different origin.  At the moment, Wales is a possible candidate.

Other Relevant Papers

The Beaker phenomenon and the genomic transformation of northwest Europe -  (Published February 2018 - full paper by subscription)

Insular Celtic population structure and genomic footprints of migration -  (Published January 2018)

The Irish DNA Atlas: Revealing Fine-Scale Population Structure and History within Ireland -  (Published December 2017)

Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome -  (Published January 2016)

Last updated 7th April 2020