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  • 400 members

About us

This project was launched by Patricia Greber around2006. She coerced Bill and Jim McMahon into joining her in the task of management and the Project has been expanding ever since. In April 2012, Patrick McMahon joined as a Project Co-administrator. Patrick is a retired geneticist living in Wexford and has been an Administrator for the 'Clan Colla425 Null Project' since 2009. Patrick has run the McMahon Project as Administrator since 2012.

The project continues to grow and there are emerging McMahon (and derivative) categories. The DNA technology is providing insights into the different McMahon branches. In Jan 2014 there were 130 McMahons in the Project (inclusive of those with different names but McMahon type DNA). The current (May 2019) membership of Y-DNA testers in the Project is 246 distributed into 12 major groupings (exclusive of 49 who are unmatched or unclassified). Details can be seen in the Project Website under DNA Results>Classic Chart etc. (https://www.familytreedna.com/groups/mcmahon/dna-results) and under About us>Results (https://www.familytreedna.com/groups/mcmahon/about/results).

If you are a McMahon or one of the Project specified names, then come and join the Project. We will try our best to position you in one of the Project groups and advise you on the best tests to achieve this.

Very Important Information about Joining the Project

If you join the project, be sure the administrators have Limited Access to your kit so they can see your matches. Only join this project if:

  • you are interested in paternal ancestry,
  • your tester has done Y-DNA testing (male tester only), and
  • the FTDNA predicted haplogroup is of the R-M269 type.

Family Finder and mt-DNA testing will not help you track your paternal ancestry in this Project.

This DNA project is not one of the very general projects such as Ireland DNA, and it is not a general surname catch all, where anyone can join no matter what their DNA markers are.  Not everyone who has the McMahon (or associated) surnames, will necessarily have markers that match the DNA of existing members or testers may match the DNA but not the surname(s).

Testing Alternatives

  1. 67 STRs: This is the recommended level of testing as it includes key Clan Colla STRs, 511=9 and 425=0. The 67-STR test distinguishes Colla McMahon from non-Colla McMahon, an essential first step in the analysis.
  2. 111 STRs: Testing 111 STR markers gives greater precision, which includes confirmatory Clan Colla STRs; 505=9, and 441=12. The 111-marker test verifies Clan Colla DNA.
  3. SNP Pack Tests: Testing with Packs containing the later SNPs is an economical way of positioning a tester on the Phylogenetic Tree. This is less expensive than Big Y testing but carries the risk of choosing the ‘wrong’ Pack (for your profile). The SNP pack usually provides downstream SNP matches but does not test for recently-discovered downstream SNPs nor reveal your unique SNPs that may eventually form new subclades with other testers.
  4. Big Y SNPs: Testing for SNPs on a large portion of your Y chromosome through BIG Y-700. This is the ultimate in Y-DNA testing at FTDNA. Using the latest technology, this maps your entire lineage in SNPs through to your most recent SNP. There are three parts to the Big Y-700 test:
        - Big Y SNPs.
        - Automatic upgrade to 111 STRs for those who have not done 111 STRs.
        - Additional 589 STRs, to bring the total STRs to 700.
  5. Individual SNPs: Testing for single SNPs, although very cheap, is a risky step as it presupposes you have correctly positioned yourself from your STR results.
  6. Upstream SNP Packs: Testing for SNPs in the M343, P312, L21, and DF21 SNP Packs are of limited use as they stop short of the most recent distinguishing SNPs. 

McMahon Subgroups

In order to better understand the DNA data that has been accumulated, the public Results page for the McMahon Project has been broken down into haplogroups. These haplogroups are based:

  • Primarily on the most terminal SNP
  • Genetic distance among group members (for those without SNP data)
  • Uniqueness of certain STRs

The composition of a Haplogroup can be:

  • A tester who doesn’t share his SNP with anyone or demonstrate STR clustering with other testers i.e. a singleton who may simply be the only one who tested in this group.
  • Testers who have related SNPs i.e. nested SNPs.
  • Testers with an SNP and others whose STR values cluster with the SNP holder.

Patrick McMahon                                                                                         Richard Raney

Mount Alexander                                                                                          3410 Martin Rd.

Gorey Y25 N799                                                                                           Clinton, NY 13323

Ireland                                                                                                            USA

(patgorey@yahoo.co.uk)                                                                              (snugaza@aol.com)