RL21 4466&SouthIrish

  • 1431 members

About us

News release dated May 2015:
Project and paper update:  

     Paper: https://www.dropbox.com/s/4w0nu96l5wdkg8g/CTS4466%20TMRCA%20Case%20Study%2009202015%20-%20fourth%20draft.doc?dl=0  

     For the detailed workbook, join the Yahoo TMRCA forum at https://groups.yahoo.com/neo/groups/R-L21_TMRCA_CaseStudies/info Under files, see 'aaa CTS4466 paper and workbook 11252015 - not for public use'

See the FTDNA TMRCA Case Study project for a list of our current research. 

See CTS4466 SNP and TMRCA graphic below.

As a volunteer admin with FTDNA, I have been studying the South Irish Haplogroup for 5 years, now labeled the CTS4466 SNP Haplogroup because of the newly discovered SNP. We have several admins on our team and have partnered with many R-L21 project admins.

I am just about to release the next 4466 TMRCA Case Study workbook may include up to 600 4466 FTDNA members. There are an additional 200 more to be included in the future. You are a close match to a member in the research group and may be CTS4466 are likely in the group of 600 in this research group.  Because my work will be published and available to the public, I need your formal opt in. I also invite you to join the 4466&South Irish project. https://www.familytreedna.com/public/TMRCACaseStudies/default.aspx

The South Irish is taking on a broader context meaning those whose ancestors came from Southern Ireland rather than a specific Haplogroup.  This is mainly because at least one of the sub branches of the previously known South Irish haplotype may have not originated in Southern Ireland but migrated northward to Northern Ireland and Scotland directly from Iberian lands.  The dating of the downstream SNPs has opened up more complex lines of inquiry.


Your kit has been identified from our member close matches which count mutation differences among member’s markers.  What needs to be considered is convergence and patterns in the marker values.  FTDNA handles these differences through statistical analysis.  We need to identify member’s SNPs and marker patterns by testing for the former and building phylogenetictrees and sub branches for the latter.  Some who closely match are members are in a different Haplogroup.  One of the most common converging Haplogroups is the Z253. Several of our members matched CTS4466, had ancestry in Southern Ireland, identified with their Eoganacht surname and found through testing they were in another Haplogroup. The best way to confirm your SNP is totest for it.  Our goal is to better understand everyone’s sub branch whether they are CTS4466 or another Haplogroup. Because the term South Irish is now being referred to all ancestors from Southern Ireland, you are joining a project that will further your ancestral search.

Thisis our second effort in identifying CTS4466 members through our member’s close matches.  Many of these new members that joined our project didn’t know they possibly were CTS4466+. 

If you are not CTS4466, you will benefit from the current research because all methods will be reused for other Haplogroups.

The 4466 TMRCA CaseStudy workbook only includes publicly available information found online at FTDNA; kit number, ancestor and STRs.  Any detailed information needed for publication of my papers will include a specific release from you at a later date.


Our team has been identifying SNPs as the Big Y test results arrive, but this is just the beginning of our research (see ‘CTS4466 S1135 Tree 01242014.png’attached).  We are looking to find every member’s sub branch so they can benefit from their common history.

First I identify the entire CTS4466 Haplogroup in FTDNA based on testing or prediction.  I build an STR SNP signature for those who have tested CTS4466+.  I then identify those that fall into the current STR SNP signature and place the others into a review group for when knew CTS4466+ results expand the signature.  This review group is created because SNP  prediction is not 100% due to convergence, that is members having the same STRs with different SNPs.

I then build phylogenetic sub branches and calculate the date for the sub SNPs. 

Phylogenetic trees are a de facto standard in biology and are useful for organizing knowledge of structuring classifications and for providing insight into events that occurred during evolution.  Pattern matching doesn’t group members as much as anticipate whether they are related.  The second issue, after ordering yDNA by relationships, is to identify how closely they are related.  Surprisingly mutation counting doesn’t necessarily help in determining whether you are related.  In fact,a single mutation may place members in different SNP or sub SNP branches and 7or 8 mutations can place members in the same sub branch.  It’s not the counting of mutations but where these mutations occur.  This is absolutely cleared up by using phylogenetic trees and sub branches with the caveat that sub SNPs need to be organized prior to being placed into a tree.  You can see the need for an iterative approach.

I am currently working with four surname sub branches that are considered a lineage to link their yDNA to their family records.  Their case studies will provide you knowledge of what can be possible.  They are the Macaulay, Thrasher, McGee and MacFarlane lineages.

Again the caveat is that sub SNPs are first identified and are a moving target. Many in the research group have only been tested or predicted CTS4466 but have not tested for downstream sub SNPS.  These are then placed into a main subbranch by STRs only and into phylogenetic order.  These members need additional testing to be placed into the downstream sub SNP sub branches (see graphic of SNP tree),  What is interesting with this group is that many sub branches, in this phylogenetic sub branch without downstream SNP order,have strong surname groups.  There is a good possibility they may be related and/or share a sub SNP yet to be tested or discovered.

The current sub SNP dating has provided significant understanding of the history of the Haplogroup.  In fact the dating of the 4466 SNPs may change the way we view accepted history or at least start more in-depth research to link yDNA SNPs and history; see attached ‘CTS4466 TMRCAs.jpg.


There is much we have learned from our SNP analysis when applying TMRCAs to the subbranches.  For example the 4466-T2-C group, now testing positive for A212/A218, is just younger than the CTS4466 SNP itself.  This group has family histories in Northern Ireland and Scotland.  There were historical writings that they had were Eoganacht descendants that migrated northward during times of famine and had been part of the Dal Raida of Southern Ireland.  The current dating of the A212/A218 brings this into question,although it doesn’t nullify the possibility it opens up reasonable doubt simply due to the TMRCA for the SNPs.  Did their ancestors migrate directly from Iberian lands northward? The dating of a SNP provides immense knowledge to those who belong in these SNP sub branches.

L270 has been found in 20 members.  12 of the 20 (60%)  testing L270+ are Sullivan’s with an additional 2 with no South Irish ancestry one a Scot and the other English, 3 with unknown history, with 1 with Daly and the other McCarthy surnames.  There is continuing to be a sub clan signature theme which is remarkable and meaningful.  4 of these Sullivan’s have only tested to 37markers.  Reviewing the family histories of the sub branch members, it maybe that L270 is decidedly Sullivan Beare for the most part.  There is one McGillicuddy, which is a Sullivan cadet name for the Sullivan Mor clan. Is there a Sullivan Beare signature different from the Sullivan Mor?  Or perhaps more dominant in the former or the latter?  So much is left to be learned.  Of the three L270+ members who have taken the Big Y test, they all have additional unnamed SNPs that are decidedly different from each other which points to the fact that they will most likely split again.  Do the Daly and McCarthy L270+ also have different downstream sub SNPs?

What is interesting is that only the L270, with a TMRCA of approx. 1298 AD, have consistent surnames/ancestry for the sub SNPs that have been discovered.  There is good reason to think the older SNPs have more variety if they occurred before or during 900-1100 AD when surnames had not been or were first being adopted.  Younger SNPs occurred when surnames were commonplace which helps to account for the consistency.


We would like to include you in our publication of our latest research, as well as invite you to join our project.  The examples above show what is possible for each and every sub branch including yours.

[67 markers are needed to be included in the research group.  If you have less than 67markers and the CTS4466 signature, you will be included in the research. Hopefully you’ll have the opportunity to upgrade at a later date and/or test for CTS4466 SNPs]

Kathleen Kerwin

FTDNA admin for the 4466&South Irish, Eoganacht septs, Sullivan and TMRCA projects. 9/20/2014

The R-L21 4466 South Irish Project was created to identify the specific unique 's that characterize the cluster, as well as research the base haplotype with the goal of understanding the Eoganacht sept/clan/surnames and their relationship to the CTS4466+ SNP and the South Irish base haplotype.  The original markers of the South Irish were identified by Dr. Kenneth Nordvedt.  

The related TMRCA calculations and phylogenetic base haplotype relationships are based on work from Dr. Anatole Klyosov.

Papers in progress:

-Forensic yDNA research of the 4466 South Irish Base Haplotype

-Forensic yDNA Case Studies

-Eoganacht sept name variants and base haplotypes

Admin:Kathleen Sullivan Kerwin

Co-administrator: James Kane; bioinformatics developer

Co-administrator: Ron McRaney; our right hand, A212/A218 admin, and reviewer