Ireland yDNA

Irish Y-Chromosome project
  • 11143 members


Y-DNA Made Simple

Life can be complicated and so can DNA which should not be too surprising given DNA is the building block for life itself! In life there are no absolutes, no simple black and white answers for every situation. The same for Y-DNA.

However, life situations can be made simpler if an overview is taken that looks at the essentials and by-passes confusing detail. Everyone at first has problems understanding their Y-DNA test results, however no-one needs to be a scientist to understand Y-DNA. Also more often than not, the results are quite different to what people expected or thought they would get. As this scenario plays out time and time again with new testers, this simplified overview of Y-DNA is intended as a starting place to dispel misconceptions and provide some understanding of what Y-DNA can and cannot do.

Testing companies market Y-DNA on ‘potential’ results but ‘actual’results rarely match the ‘full potential’ expected. Although this can be disappointing, it does not lessen the potential of the test.

Y-DNA is essentially about matching and therefore a 'team activity'.Without group participation there can be no results to compare and match. A Catch-22 situation as without all the people that have already tested no matching could be done. For those who find they have no matches, someone has to be the first but the potential to find new matches with time is the same for everyone as more people test.

Jargon that needs to be understood (but not scientifically) as it is mentioned often is:

With Y-DNA it is possible to trace aman’s paternal line from 20,000 years ago to present. Currently inorder to maximize the potential discoveries that Y-DNA can uncover, a Y-67 or Y-111 STR test combined with a NGS test like Big-Y is needed. However part discoveries can be made with STR testing alone. Further testing with SNP Packs has the potential to find the youngest known SNP but currently this is unlikely to be within a genealogical time frame. Below is a table summarising what each Y-DNA test can and cannot do:

For more information about SNP testing go to (note this 2012 information was before NGS testing became available/affordable in 2014).

The essentials of Y-DNA are:

  1. STR test to :

    1. Conservatively estimate a haplogroup;

    2. Find for surname matches with a close GD.

  2. SNP test to:

    1. Better define the relationship with surname matches;

    2. Find men with different surnames but who match the same SNP.

  3. NGS SNP ‘discovery’ test to:

    1. Discover Novel Variants;

    2. Match Novel Variants with other men and grow the Y-Tree;

    3. Find relationships within a genealogical time frame by eventually finding matches for all Novel Variants.

  4. Many people testing, the more the better and the wider the coverage/countries the better. If a NGS test like Big-Y is an option there is no need to SNP Pack test like the R-M343 Backbone.

In 2006, at the start of the FTDNA R1b ALL Subclades Project it had 100 participants, now 10 years later has grown a hundred-fold to over 11,000.

The field of DNA genetic genealogy is very new and it has been citizen scientists at the forefront of discoveries in the past 10 years. The citizen scientists making progress in Y-DNA include the volunteer project administrators who provide advice and help with no financial assistance from any testing companies or outside organisations. So what is currently known is largely due to project administrators/citizen scientists and the collective pool of DNA data from the 10,000s of people who have already STR tested and the 10-15% of men who have gone on to take a NGS test.

Trust the table summarising what Y-DNA can and cannot do helps people new to Y-DNA with their decisions on what test(s) to take.

Written by Alan Kane, NZ

28 August 2016


What is the DONATE button?

The Donate button is where project members can voluntarily donate funds to the group fund which can be used for various purposes such as sponsorship of tests for other members. Donations to the Ireland yDNA project can help to pay for SNP testing which helps us learn more about the branches of the y-haplotree which occur in Irish yDNA.

All, as many of you know the "Colorized Chart" under the DNA Results tab will throw an error (Houston we have a problem), this issue has been raised a number of times and has let to be fixed by FTDNA. While doing some experiments this morning I think I found a work around that will fix it for most people. You need to do following:
1. In the "Markers" drop down select the level of testing you've done (eg. Y-DNA67)
2. Untick the "Show all columns" tickbox
3. Change the page size to 9,000, you should than be able to view report and do a "ctrl-F" (find in page) to find your specific kit number.
Paul Duffy

updated June 2019 (Margaret Jordan)