Monday, 21 June 2021

The Limerick O'Malley's sprout a new branch (Groups 2a, 2b, 2c & now 2d)

Some new Big Y results have recently come back from the lab which have split the Group 2 O'Malley's into two distinct groups. Previously we had three groups of O'Malley's with a DNA signature that suggested that they were from Limerick - now we have four!

I have also taken the opportunity to group the Limerick O'Malley's into one larger group, with subgroups entitled 2a, 2b, 2c and 2d. This will facilitate comparison between these groups on the project's Results Page:

  • Group 2a was previously Group 2 (which is now reserved for likely L226+ participants who cannot be placed in any of the other subgroups)
  • Group 2b was previously Group 6
  • Group 2c was previously Group 7
  • Group 2d is an entirely new group, briefly known as Group 9

The SNP Sequences (i.e. list of ancestral SNP markers) for these 4 subgroups are as follows [1] ...

  • Group 2a ... R-L226 > FGC5660 > Z17669 > FGC79628 > DC63 > BY4101 > DC362 > DC735
  • Group 2b ... R-L226 > FGC5660 > Z17669 > FGC79628 > DC63 > BY4101 > DC362
  • Group 2c ... R-L226 > FGC5660 > Z17669 > ZZ31_1 > FGC5628 > BY4102 > DC40 > FT62906 > FT159770 > FT244455 > FT242218
  • Group 2d ... R-L226 > FGC5660 > Z17669 > ZZ31_1 > DC194

Note that all of these four groups start with the branch of the Tree of Mankind characterised by the SNP marker L226 (which is at least 1500 years old and may be up to 4000 years old). This Irish DNA marker is associated with the tribe of the Dál gCais with origins in the Limerick / Clare area (their descendants are known as Dalcassian). [2] It is also quite distinct from the DNA marker associated with the Mayo O'Malley's (namely M222 - more about this in a subsequent post). 

People in these four groups would be (very) distant cousins to legendary Irish hero Brian Boru, the first High King of Ireland, who defeated the Vikings at the Battle of Clontarf in 1014. For comparison, his estimated SNP Sequence [3] is as follows:

  • Brian Boru ... R-L226 > FGC5660 > Z17669 > ZZ31_1 > FGC5628 > FGC5623 > FGC5659 > ZZ34_1 > DC782 > Y5610

From the above, it can be seen that the group most closely related to Brian Boru is Group 2c - they share the common SNP marker FGC5628 (which is at least 1200 years old).

Some research into medieval records revealed that the O'Malley surname has been present in Limerick since the 1100s and I covered this in a previous blog post and the presentation below ...

Because the primary goal of the project is to study the origins and evolution of the O'Malley surname, and because surnames arose in Ireland roughly 1000 years ago, this timepoint serves as an arbitrary cut-off for the separation of people into distinct groups. Thus if two project members are believed to be related to each other within the last 1000 years, then they are grouped together in the same genetic group. And if their common ancestor is believed to be >1000 years ago, then they are placed into separate groups. The challenge is trying to decide whether the common ancestor between two people is less than or more than 1000 years ago. 

SNP tests (such as the Big Y) can be very helpful in this regard, but the methods used to calculate TMRCA estimates (i.e. Time to Most Recent Common Ancestor) will always be imprecise. Their accuracy may improve as the technology develops, but the estimates will always be imprecise and they will always have a large margin of error on either side of the midpoint estimate (say plus or minus 200-300 years). 

Estimating TMRCAs is like doing brain surgery with binoculars and boxing gloves. The tools we have at our disposal are simply not good enough for the job we want them to do ... and this is unlikely to change for the foreseeable future (although initiatives like our Extensive Lineage Project will help). Thus all TMRCA estimates will remain imprecise and must be taken with a large grain of salt. In most situations, the best they will ever do is give us a "ball park figure".

Group 2a & Group 2b

From the above SNP Sequences, it can clearly be seen that Groups 2a and 2b share an ancestor who would have carried the SNP marker DC362. A crude estimate of when this ancestor would have lived is about 700 AD +/- 300 years (there are about 16 SNPs "downstream" of DC362 according to FTDNA's Block Tree, so allowing 80 years per SNP gives us this crude estimate: 16 x 80 = 1280 years before present, and 1950 - 1280 = 670 AD, which rounds up to 700 AD). This means that the common ancestor between Groups 2a and 2b probably lived before the time of surnames, and therefore Groups 2a and 2b probably had different origins for their O'Malley surname. 

The alternative theory is that these groups had a similar origin and just happen to be very distantly-related to each other, but the current age estimates for their common ancestor (DC362) tend to go against this theory.

FTDNA's Block Tree showing the Big Y-tested member of Group 2b (indicated by "Your Branch" on the far right) sits on a separate branch below DC362 (encircled in red) beside people called Daily, Griffin, O'Loughlin, the Group 2a O'Malley's, Curry/Currie, and (out of frame) McInerney, Slattery & McNamara. 
(click to enlarge)

I contacted Mike Sager (Big Y guru at FTDNA) and he double-checked the results of the Big Y-tested member of Group 2b (PM-0138). [4]  Mike says there is no sign that this member has any of the SNP markers on Group 2a's DC735 branch, or any other branch below DC362 for that matter. Furthermore, this member (PM-0138) has 12 Private Variants (i.e. unique SNPs, not shared by anyone else in the database) and this further supports the contention that he currently sits on a rather isolated branch of the Tree of Mankind. Moreover, turning to the STR results for PM-0138, these indicate a large Genetic Distance (GD) between him and members of Group 2a (the GD ranges from 15/111 to 17/111, and 13/67 to 15/67). This further supports the contention that Group 2a and Group 2b are only very distantly related and that the two groups are genetically distinct. And because their common ancestor is likely to have lived prior to the time of surnames, the O'Malley surname that each group now carries arose from different sources. 

This new data raises several important questions:

  1. where did each group get the O'Malley name from?
  2. does one group still carry the Y-DNA of the surname founder?
  3. did one (or both) groups have a different surname before they became O'Malley's?

Hopefully the answers to these questions will become clear as more people do the Big Y test.

Similar questions can be asked about the other two groups with presumed Limerick / Clare origins - Group 2c and the newly formed Group 2d (see below).

The majority of the Group 2a O'Malley's come from the areas of Murroe and Cappamore. They have been carrying this particular DNA signature in association with their O'Malley surname for at least 300 years approximately (based on midpoint estimates from the TiP Report of the most distantly-related group members).

The origins of the Group 2b O'Malley's are unclear. One of the two members has roots in Connaught, the other in Limerick. Their common ancestor appears to have lived about 14 generations ago (based on the midpoint estimate from their TiP Report), which equates with about 420 years ago or roughly 1530 AD ... but we can add a crude range of +/- 200 years to all these estimates (i.e. 1330 to 1730 AD).

Group 2c & Group 2d

Recent Big Y results (June 2021) for TOM-2541 indicate that he is incorrectly placed within Group 2a. [4] Previously, his STR results had suggested that he might belong to an ancient branch of the Group 2a O'Malley's, and this would have been a very exciting find because it would have pushed back the age of the group by several hundred years. However, his Big Y results now confirm that he belongs to a genetically distinct group, and is actually more closely related to those in Group 2c. And thus a new group is born - Group 2d.

To recap, the SNP Sequences for these two groups are as follows:

  • Group 2c ... R-L226 > FGC5660 > Z17669 > ZZ31_1 > FGC5628 > BY4102 > DC40 > FT62906 > FT159770 > FT244455 > FT242218
  • Group 2d ... R-L226 > FGC5660 > Z17669 > ZZ31_1 > DC194

From this we can see that the common ancestor shared by these two groups would have carried the SNP marker ZZ31_1 and this is at least 1200 years old. This is just before the advent of surnames in Ireland (i.e. about 1000 years ago) and therefore TOM-2541 belongs to a genetic group of O’Malley’s that is genetically distinct from the other three groups. You can see this new group on the Results Page of the project and (for now) TOM-2541 is the sole member.

The screenshot below from FTDNA’s Block Tree shows that there are several people sitting on branches adjacent to TOM-2541 and these people carry the surnames Rines, Barkholz, Tuohey, Batsakis & FitzPatrick. There are no other O’Malley’s on this DC194 branch.

The DC194 branch on FTDNA's Block Tree - this seems to be a rare branch of O'Malley's

TOM-2541 has 7 Private Variants (i.e. unique SNPs not shared with anyone else in the database … currently) and this suggests that the common ancestor he shares with his closest Big Y match lived about (7 x 80 =) 560 years before present, which equates with (1950-560 =) 1390 AD, which rounds up to 1400 AD. So he has no close matches on his Big Y test.

Turning to his STR results, he now has data for 111 markers (as opposed to the initial 37 markers he tested previously). At the 111-marker level of comparison, he has no DNA matches. This in itself suggests that he sits on a relatively isolated branch of the Tree of Mankind. At the 67-marker level, he has 150 matches, and none of them are Malley’s or O’Malley’s. His closest matches are men called Grealish & Tuohey. The most common surnames among his 150 matches are Brien/Bryant/O’Brien (17), Hogan (4), Kennedy (6), Lindsey (6), McGraw (5), McNamara (3), & Slattery (4). At the 37-marker level, he has 25 matches, and again none of them are Malley’s or O’Malley’s. His MDKA (Most Distant Known Ancestor) goes back to Ennis in Co. Clare.

Selection of STR Matches for TOM-2541 - the Terminal SNP (2nd column from right) indicates that most of these matches sit on adjacent branches to his DC194 branch

So it may very well be that he sits on a very rare branch of O'Malley's with very few surviving O'Malley men, of which he is the first one to be tested. Alternatively, there may have been a surname change somewhere along his direct male line, and prior to being O’Malley’s, his direct male line ancestors went by another name. This is not too surprising as such name changes were relatively common over the centuries and they arose for a variety of different reasons. However, there is no other name that stands out from the list of most common surnames among his matches and we can see from their “Terminal SNPs” that most of them are on adjacent branches to his DC194 branch.

So for now, TOM-2541 has no close O’Malley matches and the deeper origins of his O’Malley name remain uncertain. But hopefully in time more people will test and he will discover some closer matches that will help shed light on this current mystery.

In this sort of situation, it can be helpful to do the Y-DNA test on some other known O’Malley cousins (the more distant the better). This may help inform us where the surname switch is likely to have occurred. My colleague Lisa Little had a similar conundrum and wrote a blog post about how she approached solving it here.

Because he is the only person in Group 2d, it is not possible to tell how long his particular DNA signature has been associated with the O'Malley name. 

Group 2c consists of 3 O'Malley men, two of whom have done the Big Y. One has origins in Castleton Cross, the other two from "Ireland". Their common ancestor lived about 9 generations ago (based on a midpoint estimate from the TiP Report). This roughly equates with 270 years before present (taken to be 1950), which is roughly 1680 AD (+/-200 years). If we use SNP Counting, we get an older estimate ... at least 400-560 years old approximately (i.e. 5 Private Variants on average, but 7 SNPs in the left-hand column on the Block Tree, so 5 x 80 = 400 ybp, and 7 x 80 = 560 ybp).

So any DNA switch (if there was one) probably happened some time before 1650 AD. As more people join the database and fall on this branch (FT242218), we may get a better estimate of how old this group is i.e. how long they have been carrying the O'Malley surname. For now we can say that it is at least 350 years old and possibly over 600 years old, but this age estimate may be pushed back with additional data and it may even go all the way back to 1000 years ago, in which case this group may become prime contenders for the original Limerick O’Malley's.

Group 2c has carried the O'Malley surname for at least 350 years, possibly 600 or more


There are now 4 groups of O'Malley's from Limerick and any one of them could represent descendants of the original O'Malley's whose ancestral territory was centred around the present day townland of Ballyclough (in the Civil Parish of Knocknagaul and in the Barony of Pubblebrien - see previous blog post here). However, it is likely that only one group represents the descendants of the original Limerick O'Malley's and the others have had a Surname or DNA Switch somewhere along their direct male line (in the recent or distant past).

Given that the group with the most people is Group 2a (with 10 members), this is currently the leading contender for the descendants of the original Limerick O'Malley's, but it could simply be that more people in this group (than the others) have survived to the present day, or have been DNA-tested ... so this could be creating a false impression of dominance.

Whatever the truth is, additional recruits and further Big Y testing will help address this question in time. 

And no matter which group represents the original descendants, it is important to remember that "an O'Malley by any other name would smell as sweet".

Ancestral origins for the Limerick O'Malley's - Ballyclough was the ancient territory of the O'Malley's (as described in medieval texts), whereas Murroe & Cappamore are MDKA locations for Group 2a.
(click to enlarge)

Maurice Gleeson
June 2021

On subsequent review of the Ungrouped section, it was apparent that two additional O'Malley men (who had done Big Y testing) also sit on branches below L226. Therefore, two new subgroups have been formed within Group 2, namely Group 2e and Group 2f. Both subgroups only contain one single individual ... currently. These new subgroups are detailed in this subsequent blog post.


[1] SNP Sequences are easily generated by entering your terminal SNP into the SNP to Breadcrumbs tool on the Tracking Back website.

[2] For more info on the L226 marker and the fascinating story of the discovery of its origins, check out the following links ...

[3] courtesy of Dennis O'Brien, Admin of the O'Brien DNA Project

[4] PM-0138 and TOM-2541 refers to the initials of the test-taker and the last 4 digits of his kit number

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