Group 3a, the Mayo O'Malley's - current status

We announced in the previous post that we are seeking a research grant for funding of about 20 Big Y tests. This will hopefully help us identify the Y-DNA signature of Grace O'Malley's forbears and will allow people to establish a direct genetic relationship to Grace herself.

Grace belonged to the O'Malley clan of Mayo, and there is every indication that the members of Group 3a are descendants of this clan (see previous post here). Let's take a look at the current status of this group, as this will serve as the starting point for the additional Big Y testing (if funding is approved).

There are currently 36 people in this group, and DNA results are awaited from an additional 5 people, all of whom claim descent from one of Grace's immediate male forbears (going back to her great great grandfather). Fifteen (15) of these 36 people have already done the Big Y test. These results can be seen on the public Results Page here.

Long shot of the analysis of Group 3a

The Big Y results allow us to sort the members of this group into four distinct branches. And in addition, Unique STR Patterns (USP) allow us to identify several additional branches. These are summarised in the diagrams below. This tabular summary was created by downloading the data from the Results Page and adding in additional columns for the following:

1. SNP Sequence (i.e. list of ancestral SNPs)
2. Private SNPs (i.e. unique to the individual ... currently. This may change as more people do the Big Y test)
3. Big Y test type (500 or 700 i.e. pre- or post- Jan 2019)
4. reported Ancestral Location (townland or parish where available)
5. sources for the Direct Male Line pedigree (either a family tree on FTDNA, an entry on our Post Your Pedigree page, a tree on Ancestry, or an email)
6. Direct Male Line pedigrees (showing each generation back to the Most Distant Known Ancestor)

Note that some people have left their project settings on the default setting and this prevents the display of their data on public pages so this has been hidden where necessary by blue bars in the diagrams below.

Let's take a walk through each of the branches identified so far.

The Blue Branch

(click to enlarge)

The blue branch consists of 5 people currently. Only two of them have done Big Y testing and this identifies that they share the "terminal SNP" FT145889 which places them on the same downstream branch, associated with the following (abbreviated) SNP Sequence:

• R-L21 >> DF13 >> DF49 >> M222 >> DF105 > BY35731 (3) > BY35736 (2) > BY35730 (2) > BY35760 (5) > FT86146 (1) > FT145889 (4) ... the numbers in brackets refer to the number of SNPs in the "SNP Block" associated with that particular branch - see the Block Tree diagram at the end of this article for a visual representation of this. All group 3a O'Malley's fall under BY35730, and this suggests that the common ancestor to all Group 3a O'Malley's carried this marker and passed it down to all his descendants.

The two SNP-tested men only have 1-2 "Private variants" (i.e. SNPs unique to each of them individually) so this suggests a common ancestor in the recent past (i.e. 80-160 years before "present", which is taken to be about 1950, so about 1790 to 1870). They only have a Genetic Distance (GD) of 2/111, and this again suggests a close connection. In fact, their genealogical data indicates that they have a common ancestor (Myles F O'Malley) who was born in 1886, so the DNA confirms this close connection.

The other 3 people on this blue branch appear to be relatively close matches to the first two men, but only Big Y testing will confirm whether or not they have been correctly placed here. They could potentially sit on a completely separate sub-branch, and their STR marker values are simply matching those of the first two men "by chance" (a consequence of significant Convergence in Group 3a).

The longest reported pedigrees go back to 1740. Reported ancestral locations for this branch are non-specific. They include London and Mayo, with one person reporting Westport as a possible ancestral location.

The Pink Branch

(click to enlarge)

The pink branch is the largest in the project (currently). Seven (7) of the 9 members have done the Big Y and all share the "terminal SNP" FT86146, which is a branch one step up from the blue branch. Of the two men who have not done Big Y testing, one is a 1st cousin of one of the Big Y testers (and they are an exact match at 37 markers), and the other has a GD of 1/37 to his closest match within this pink group, so both are likely to have been accurately grouped.

The common ancestor for this branch lived about 1450 AD (+/-300 years). The calculations for this estimated TMRCA (Time to Most Recent Common Ancestor) are as follows: 80 years per SNP, 6 SNPs on average back to the MRCA (see Block Tree diagram at end of article for SNP details), 80 x 6 = 480, subtracted from 1950 = 1470, rounded to nearest 50 years = 1450.

The longest reported pedigrees go back to 1745. Localised ancestral locations include Kilmeena, Ballyhaunis & Rossanrubble.

The Green Branch

(click to enlarge)

The green group all sit on a branch one step further back than the pink group. This branch is characterised by the upstream SNP BY35760 (one of 5 in the SNP Block for this branch). Also, this branch is likely to be split in two as more Big Y results come in. The 4 members in the light green group all share a value of 10 for the 4th STR marker; and 3 of them have a USP (Unique STR Pattern) characterised by values of 9, 15, 16, 12, 36 & 36 for markers number 15, 23, 25, 27, 34 & 35 respectively. This USP suggests that they are all closely related.

The longest reported pedigree goes back to about 1780. The common ancestor for the entire green branch lived about 80 years prior to the one for the pink branch, so about 1400 AD (+/-300 years).

Reported ancestral locations include Louisburgh, Westport, Clare Island, & Kilmeena.

The Red Branch

(click to enlarge)

The red branch now only consists of one person, suggesting that this is quite an ancient branch of the clan. This is again one step further up from the previous (green) branch and is simply characterised by BY35730 - the overarching SNP for all the Group 3a O'Malley's.

The MDKA for this individual was born in 1756. The common ancestor with the rest of Group 3a members lived about 1150 AD (+/-300 years), which could be reasonably close to when the O'Malley surname first came into common usage.

The Orange Branch

(click to enlarge)

The final group is the orange branch. None of the 8 current members have been Big Y-tested as yet, but they all share at least part of a very distinctive USP (Unique STR Pattern). This is quite evident from the coloured squares in the screenshot above. The USP is characterised by the values of 13, 29, 17 or 18, 18, 38 & 39 for marker numbers 9, 12, 32, 33, 34 & 35.

Within this USP there are two sub-USPs: 

1. the first 4 men have a value of 11 for marker 37 (the only people in Group 3a to have this value)
2. the 5th & 6th men have values of 18, 14 & 29 for marker numbers 13, 19 & 21. With luck, Big Y testing will identify a specific downstream SNP marker that is associated with these additional sub-USPs, thus confirming that they are indeed downstream sub-branches.

Interestingly, three of the men in this group have a reported lineage that goes back to Seán na Firinne O'Malley (1740-1801), who in turn is reported to be a direct descendant of Cormac, grandfather of Grace O'Malley. Thus, this particular branch is possibly the most likely to be the closest-related to the immediate male forbears of Grace O'Malley. It will be interesting to see if this theory is borne out by the results from candidates currently being recruited who also have extensive pedigrees back to Grace's male forbears.

If this is the branch most closely related to Grace, the USP described above will be very useful for identifying future branch members as it only requires a simple Y-DNA-37 test to detect the tell-tale USP.

Lastly, by plotting the various reported ancestral locations onto a map, we can see that there is a tendency for members of the green branch to cluster around Westport and along the coast out to Clare Island, whereas members of the orange branch are more inland, around Lough Mask (south Mayo / north Galway). Whether this continues to be the case as more people join the group remains to be seen.

Ancestral townlands or parishes reported by Group 3a members
showing apparent separation into distinct areas
(available on Google Maps here) 

So far we have identified 16 descendant lines that we would like to approach for testing (Y-DNA-37 initially, then Big Y) and currently 3 people have completed initial testing and their results place them all in the orange group. An additional 4 people have agreed to be tested and we are pre-swabbing them in the hope that we secure funding for their tests. Genealogical exploration continues (by Brendan O'Malley, Emer Gunter & Tom O'Malley) to identify candidates from the remaining 9 descendant lines for anticipatory pre-swabbing.

But will they all fall into the orange group?

Watch this space!

Maurice Gleeson

Mar 2022

Big Y Block Tree - the current configuration of the tree showing Group 3a members
and their nearest genetic neighbours (Rush, Arnold, Gaffaney & Beaty)
(Click to enlarge)