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 twenty recognised O’Donoghue ancient tribal/septal areas and fourteen associated ones in Ireland. The recognised ones were in Munster: Limerick, Tipperary, Cork, Kerry, Clare, Waterford – Leinster: Kilkenny, Wicklow/Dublin, Meath, Westmeath, Offaly – Connaught: Galway, Mayo/Sligo – Ulster: Cavan, Down. 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.

I (Rod) am the second member and handle communications to the society.

Philip O’Donoghue has joined us as a Co-administrator and is assisting us in managing the project.

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.

The Munster Irish Y-DNA Project at http://www.familytreedna.com/public/MunsterIrish/  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.

Privacy

FTDNA maintain strict privacy protocols which can be viewed at https://www.familytreedna.com/legal/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

Costs

Family Tree offers 37 and 111 STR marker tests, costing $119 and $249 respectively. The higher the number of markers chosen, the greater the detail with which we can compare results.   The most comprehensive test is the Big Y-700 which also tests SNPs in addition to 700 STR markers and provides the most detailed information available.  We recommend ordering the most extensive test affordable, but you can always upgrade to more markers and/or the Big Y-700 later on, though it is a bit more economical to order the greater coverage from the outset.

Other helpful DNA web sites

http://blairgenealogy.com/
http://genealogy.about.com/cs/geneticgenealogy/
http://isogg.org/
http://www.isogg.org/wiki

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
Rod O’Donoghue (rod@odonoghue.co.uk) – Group Administrator
Philip O’Donoghue (philip.odonoghue@ntlworld.com) – Co-Administrator

Progress as at April 2026

The project is now one of the largest O’ or Mac Irish DNA programmes thanks to the work of Elizabeth O’Donoghue/Ross

Volunteers to help always welcome