The O'Dwyer Clan
Virtus Sola Nobilitas     [Virtue alone enobles]



O'Dwyer Name

"The History of the O'Dwyers"

O'Dwyer Castles

Clan Territory

O'Dwyer Music

Distribution Map

O'Dwyer DNA

Clan Association

Clan Rally 2000 Report

Links to other Irish clans......

Ryan Clan

Meagher Clan

Kennedy Clan

Murnane Clan

Links to Irish genealogy sites...

County Tipperary Historical Society

Tipperary Heritage Unit

Tipperary Libraries

O'Corrain Heraldry

O'Dwyer DNA Project

Just a short note to confirm that the O'Dwyer DNA project is now up and running.
Anybody who is interested can contact Family Tree at

On the first page you will see on the right hand side "begin with" Enter "ODwyer" here.

You can order the kit by completing this page and the test type we have chosen is the 25 Marker test.

I would recommend that you sign and return the waiver form (click to open) to myself.

Le gach deá ghuí

Pádraig Ó Duibhir
Rúnaí / Secretary
O'Dwyer Clan
E Mail:

DNA - Its Relevance to Family History

In 2001 the Genetics Department of Trinity College got involved in a project titled "Irish Origins: The genetic History and Geography of Ireland" by using DNA markers. Through the project they hope to discover new views on the different ancestral influences which shaped the island.

In order to do this they looked at a piece of DNA called the "Y chromosome", which is only passed from father to son. Surnames are also inherited in this way, so the Y chromosome and surname travel together through the male family line.It is this link that allows us to use the Y chromosome to learn about surnames.

For example, by comparing the Y Chromosome of different men with the O'Dwyer or Dwyer surname we will be able to see if all O'Dwyers and Dwyers are descended from one person or if the name arose independently several times in different parts of the country.

Only males have the Y Chromosome which is passed from father to son usually in identical form from one generation to the next. Occasionally, a change which is called a mutation occurs between a father and son. Some families have more changes than others.

The Y chromosome DNA is like a ladder with many rungs called locations. Each location is identified by a DYS number. The DNA test is carried out on a certain number of locations and is given a reading at each point. In the case of Trinity College they took a reading at 17 different locations.

Various levels of marker tests can be chosen 12, 15, 17, 25 with varying costs applied. (The more marker tests the more refined the results will be.)

In order to do this we need to to collect DNA samples from informed volunteers. The DNA collected will be examined using different markers (tests which are akin to blood group typing) and used in comparison with other people of the same surname.

The word "sample" refers to either a cheek swab or the DNA (genetic material) extracted from this. This is taken by rubbing the inside of your cheek with a small brush. The brush to be used is sterile. If applied gently there are no risks to health and the skin should not be broken. If applied roughly there may be potential for some minor bruising.

The human body has 100 million cells. A cell is a basic unit of structure in living things. Chromosomes are tiny bodies in a cell which carry the genes. A gene is a piece of DNA which carries the hereditary information. (DNA is a nucleic acid)

In an ideal world all O'Dwyer males would fit into one large group. There are several reasons why this may not occur.

  • If the surname was used by more than one tribe, there will be different paternity lines.
  • If another surname was adapted
  • If another surname was mis-spelt or written down incorrectly.
  • There were also some unusual changes in surnames. At times when a man had daughters only, he requested that his daughter's spouse took her surname in order to keep the estate in the original family name.
  • Where an adopted male took on the surname of his adoptive family, his descendents will not carry the family name Y chromosome.

The tests could be used to establish if variations of the O'Dwyer name such as Dwyre, Dwier, Dwyar, O Duvire, O Duire, Dwire etc and even the Divers and McDyers can be traced genetically to the same source.

Should the O'Dwyers wish to participate in such a project we would need to find sufficient unrelated male volunteers (25 to 30) who would be prepared to give a swab test from inside the cheek. A good regional and international spread of volunteers would also be preferable.

The volunteers names will always remain confidential as samples are labelled by county (or state) only, on arrival.

As the Trinity study has been completed we will have to fund the project ourselves.

If sufficient interest is shown in pursuing this line of study, I will undertake to coordinate it and liaise with the relevant authorities.

I can be contacted at E Mail or Mobile 087 7763941 or 091 592423.

Pádraig Ó Duibhir

O Dwyer Clan Homepage

18th - 20th September
Bru Boru

Cashel, Co. Tipperary Ireland

"The O'Dwyer Diaspora"
A book featuring experiences and stories of O'Dwyer emigrants

To enrol as a member of the O'Dwyer Clan, Click here to download membership form.

O'Dwyer DNA Project
The O'Dwyer DNA project is now up and running.
Click here for details