Paternal DNA in Family History

There are various organisations around that will test your DNA - its quite straightforward, they send you a couple of swabs, you brush the swabs round the inside of your mouth, send them back, and a month later you have the results. So far the indication is that there has been a non-parental event at some point in the past, and the Grant family "paper trail" and dna trail diverge. The paper trail shows them coming from Kilkenny and the dna shows a root somewhere round Sligo. I am now working to see when the npe might have occurred. The option that seems to fit would be if the y-dna came from one of O'Neill's Ulster army when it was roamomg through Kilkenny prior to the sieges of Clonmela nd Waterford during the Cromwellian Wars. This would be around 10 generations, or somewhere around a 60% probability that the common ancestor comes from that period or earlier.

I did my tests with Family Tree DNA. They offer tests of 12, 25 or 37 "markers" for the male lineage. These tests confirm paternal lineage and common ancestry on the male line . The 12 marker test is not enough for the "Y DNA" test, as it gives too many matches and it really will not help you, so you need at least 25 markers tested to give you any lead on a common ancestor. My male haplogroup is M222. The Haplogroup R1b is the most common haplogroup in European populations. It is believed to have expanded throughout Europe as humans re-colonized after the last glacial maximum 10-12 thousand years ago. Its branch R1b1b2e (now called R-M222) is primarily found in Ireland, and is the so called "Niall of the Nine Hostages" paternity. The Most Recent Common Ancestor MRCA for most (if not all) of the M222 group lived within the last 1500 years, give or take a couple of centuries. In other words the original daddy of all M222 lived about 500 AD. The resultant spread of surnames of those that have M222 today is due to the so called Non Parental Events that occur as lives take their courses.

Given that I have been able to trace my family history in Ireland for 1000 years, then the markers that I have should be useful for others to establish whether or not their ancestors came from the parts of Ireland that I did. But unexpectedly the results when compared with the total Family Tree DNA database shows my paternal DNA to be Irish - of the matches on 24/25 markers, 69 are from Ireland, 11 from Scotland and 13 from anywhere else in the world (including England). There is a "simple guide to dna" here

Y-Chromosome DNA (Y-DNA) is a type of DNA that is only carried by men, inherited from fathers and passed down from father to son through the generations, along the male line. This male line is said to share a common paternal ancestor, as they all have similar Y-DNA. The Y-chromosome contains millions of bits of information, each of which is encoded by a "base pair." Analysis of all these base pairs is impractical for genealogical purposes. Geneticists have identified a number of specific chromosome locations that can be used for analysis and comparison. These unique locations are generally called "markers" and when they occur on the Y-chromosome, they are typically given numeric values/names starting with the prefix "DYS", for example, DYS391.

Y-DNA is particularly useful for tracing one's direct paternal line (father, paternal grandfather, etc.) because it changes slowly from generation to generation. This is most useful, as the son in most societies usually inherits the surname of the father. Males who share a common paternal ancestor will have virtually the same Y-chromosome DNA. This of course does not mean that you have to have the same surname. There is always the Non Paternal Event, which can be anything from adoption through second marriages to illegitimacy. The mathematics of Non Paterntal events is such that if 5% of births in any one generation are "non paternal" then 40% of people will have a divergence between their surname and their dna ancestor after 10 generations.

The first thing you need to know is your Haplogroup, or where your remote ancestors came from. The vast majority of the European population is divided into three ancient ancestral groups. The markers in the Y-DNA strand are passed directly on from father to son. Nine of these markers are passed on with very little or no deviation from the ancient ancestor. These markers DYS 393, DYS 390, DYS 19/394, DYS 391, DYS 389i, DYS 389ii, DYS 392 and are used to help identify a haplogroup. With the addition of markers DYS 385a and DYS 385b it further helps to pinpoint which ancient population group one is a member of.

To grasp what the matches mean, current scientific thinking (given on ftDNA) gives us:-

match on 25 markers 50% probability of common ancestor in 90% probability 95% probability
25/25 4 generations 12 generations 15 generations
24/25 9 generations 20 generations 24 generations
23/25 14 generations 30 generations 35 generations

probability of y dna match

Armed with that information, I can go to Y-DNA matches on the Family Tree DNA site. Looking today on the 25 marker test there are 52 people with 24 out of 25 markers matching (strong probability of relationship) (this page gives the mathematical probabilities). The problem is that many have no idea where their ancestors came from.

There is further database information at YSearch.org . My user name there is PHEVJ. You can see the preponderence of Irish as a source of this DNA. The is one perfect match listed there, a William Bruce, whom I have contacted, but does not know where his family came from before they appeared in the USA around 1850. The full dna match chart is here

A cross analysis on ysearch.com is on the my haplotype R1b1b2e. If one removes the "don't know" roots and USA roots (same thing) then there are 118 with the haplotype whose ancestor came from the northern third of Ireland, only 14 from the southern two thirds of Ireland (a further 108 who just list "Ireland", 56 with "Scotland" and 22 with "England"). Of the 118 from the northern part of Ireland, 106 give a specific county. Of these the most numerous are 18 from Donegal, 15 from Antrim, 11 from Derry, 9 from Sligo, 9 from Down, 8 from Mayo. An analysis of my "recent ancestral" origins shows that the vast majority of close matches are from Ireland

When one plots the 25/25. 24/25 and 23/25 matches these two maps are what one gets. The common ancestor appears to come from around Sligo, and to have common 391=10 and 458=18 markers with me. The common ancestors appear to have migrated eastwards and the matching dna samples at 23/25 (or in probability more than 20 generations distant from me) are marked in orange on the first map below.

A full analysis of all the matches is given in

There is also a test for female lineage of both males and females. I am HVR1 Haplogroup H10, on the Mitochondrial haplogroup test. Be clear that the two test are very different. The Y test givesyou the link vis only the male line - ie the common ancestor being a great, great, ....great grandfather, so ignore the mother on every generation. The mtDNA test is only the mother's mother's.... link (ie ignore the father in every generation) Pugh y-dna on my mother's side

Calculate Time to Most Recent Common Ancestor

My research into the Grant DNA can be found here. I have set out to find and get DNA samples from as many of the Grant branches as possible, and with the results see whether and how they fit together. If you are a Grant and think that you can help with DNA, then please email me.

Return to Grant Genealogy index page

Y base Dna data bank matches

SMGF database

International Society of Genetic Geneology