Genetic Homeland map of castles in Ireland associated with surnames


The Irish Mapping DNA Project

The Irish Mapping DNA Project is intended to support research on geographic origins and patterns of surnames and Y-DNA originating in Ireland. The goal is that by comparing precise latitude and longitude origins of persons with similar Y-DNA signatures, their genetic homeland in the era of surname formation can be identified.

Although surnames have generally been passed patrilineally in Ireland, there are exceptions and so matches to surnames other than your own could mean that one branch adopted a different name based on a strong patriarch who was well known in his era.

In general, precise identification of geographic origin depends on two important factors:

  1. Having sufficient resolution in the DNA tests to indicate that the time-to-most-recent-common-ancestor (TMRCA) is 1,200 years or less. Effectively that requires a match of 33 or greater on 37-marker STR tests. In some cases a 67-marker upgrade as well as SNP testing may be recommended.
  2. Having matches whose geographic origin are known with a degree of precision. Ideally this would mean finding and testing persons in Ireland with a long geographical continuity such as traditional farmers. Failing that, persons with a good paper genealogy trail down to the parish and townland level may provide geographical pointers.

Genetic Homeland Finder Tool

Comparing map plots of surname records of persons with genetic genealogy matches with tools like the Genetic Homeland Finder tool can show patterns that are not easily recognized in traditional genealogy records.

So if you are searching for WHERE in Ireland your paternal ancestors came from, you've come to the right project. Take a look at your Y-STR matches and compare what is known about their geographic origins.

Static map image of plot of earliest known patrilineal ancestors from Ireland for participants in the Irish Mapping DNA Project

Links for More Information