Y-DNA project

The use of DNA testing for genealogists

Genealogy has to date been based on oral tradition and documentary evidence. In the last few years the science of genetics has offered a new tool – Y-DNA testing. Our DNA is made up of a number of chromosomes. The Y chromosome is only held by a man and passes from father to son. Where, therefore, people of the same name share the same DNA signature, there is a degree of probability that they also share a common ancestor. If oral tradition and documentary evidence also support this relationship, the degree of probability is significantly heightened.

The origins and distribution of the O’Donoghues (however spelt) in Ireland over time

There are fifteen known O’Donoghue ancient tribal/septal areas in Ireland. They were in Munster: Tipperary, Cork/Kerry, Clare, Waterford – Leinster: Kilkenny, Wicklow/Dublin, Meath – Connaught: Galway, Mayo/Sligo, Cavan. Considerable migration took place over the centuries and family groups took root in many other counties (eg Clare, Limerick, Waterford, Roscommon and others), which would today be recognised as their areas of origin.

People who can participate

This project is primarily for society members’ benefit, but guest researchers and a wide cross-section of people from different parts of Ireland will be invited to participate in order to build as comprehensive a database as possible. The findings of the project will be made available to all, within the privacy protocols described below. The spelling of the name has enormous variation (around 300 variants) today and this project is relevant to everyone.
If you are a female researcher, you should encourage your male O’Donoghue relatives to join the project on your behalf.

Administration of the project

We have a three person team. Elizabeth O’Donoghue/Ross (Ireland) is our Group Administrator. Elizabeth is the primary interface with participants and FTDNA, our laboratory service provider. She maintains our analysis routines and produces reports and results data. She liaises with the Breifne Clans Project (Donohoes of Cavan).

Tighe O’Donoghue/Ross (Ireland) provides expertise on ancient history and interprets the results in tribal/sept terms. He liaises with the other tribes/septs (MacCarthy, O’Shea, O’Moore etc). I (Rod) am the third member and handle communications to the society.

Family Tree DNA (FTDNA) www.familytreedna.com has been chosen as the society’s service provider. They work with the Arizona Research Labs at the University of Arizona to do all the technical and laboratory work. They operate to the strictest privacy guidelines. They have the largest database, which enables people who match each other to to be put in touch, helping to uncover common ancestors.

Other known related projects

We maintained contact with the Trinity College Dublin Irish Clans project with whom other societies and chiefs were working. The Donohoes of Cavan sponsored a portion of this medium term TCD project, for which no personal results were available for the individual. The portion supported was that relating to Brian McEvoy’s doctoral thesis, which resulted in the identification of the Ui Neill modal haplotype (now known as the Northwest Irish modal haplotype), later established as the first known haplogroup of Irish origin, defined by the M222 mutation. FTDNA have other projects with historically related names – McCarthy, O Mahony and Donnachaidh, for instance. There is a family project in County Clare with which Hilary de Birch (Member 81) is involved.

There is a new Munster Irish Y-DNA Project recently launched at http://www.familytreedna.com/public/MunsterIrish/ which is focusing on the heritage of the early peoples who populated the province and comparing their genetic relationships as indicated by Y-DNA with the claims of early genealogical tracts and annals.


FTDNA maintain strict privacy protocols which can be viewed on FamilyTreeDNA – Privacy Statement.  We suggest you read them carefully.

How to join the project

Go to the FTDNA page at http://www.familytreedna.com/surname_join.aspx?code=G98362&special=True&proj


Family Tree offers 12, 25, 37, 67 and 111 marker tests. The higher the number of markers chosen, the greater the detail with which we can compare results. We recommend ordering a minimum of 37 markers, which costs US$ 149. Though some members have 12 or 25, the majority of participants have at least this number of markers, and a growing number are requesting upgrades to 67 and 111. You can always upgrade to more markers later on, but it is a bit more economical to order a higher number from the start.

Other helpful DNA web sites


We hope that many of you will find this project of real interest and wish to participate. If you have any questions please contact our Group Administrator, Elizabeth O’Donoghue at elizabeth@odonoghueross.com.

Short term objective

Scope and objectives of the project
For the short term
* To aid those who are encountering barriers to their family history research to make breakthroughs.
* To build a data base of DNA patterns for the different origin locations across Ireland, providing directional guidance for those who do not know where their ancestors came from.
* To confirm known or suspected relationships in historic areas of O’Donoghue occupation (such as the O’Donoghues of Glenflesk/Killarney) or for people for whom oral tradition describes migration from a common location (such as the migration to Clare from Kerry).

Medium term objective

For the medium term
* Through use of the data base, to aid research into historic tribal migration and sept/clan/family group origins (eg the O’Mahonys and O’Donoghues both from Eoghanacht Raithlind).
* To co-ordinate with other societies to improve the knowledge of inter-sept relationships and common ancestry (eg MacDonogh MacCarthys in Cork).
* To compare these patterns with national/regional population profiles using a representative control group. If the incidence of a DNA signature is more common within the surname than in a wider control population the degree of probability/validity is increased.
As our database grows, these objectives will be increasingly realised.

Administrative organisation

Elizabeth O’Donoghue/Ross (elizabeth@odonoghueross.com) – Project leader and Group administrator
Tighe O’Donoghue/Ross (elizabeth@odonoghueross.com) – Tribal history expert
Mike Donahue (mdonahue@newgrange.biz) – Co-Administrator
Philip O’Donoghue (philip.odonoghue@ntlworld.com) – Co-Administrator
Rod O’Donoghue (rod@odonoghue.co.uk) – Support

The images on this page are

  1. General Irish landscape
  2. Poulnabrone – a 5000 year old dolmen on the Burren, Co. Clare
  3. A bridge in the Lakes of Killarney
  4. Killarney National Park


Specific research interests