Saturday, 26 June 2021

Group 3a - descendants of the O'Malley Clan of Murrisk & Burrishoole

In the previous article, we explored six of the seven subgroups which are M222+. Now let's turn our attention to Group 3a, the largest of the Group 3 subgroups in the O'Malley DNA Project, and the leading contender for the descendants of the O'Malley's of Murrisk & Burrishoole

Old map showing the clan territories of the Mayo O'Malley's (North is to the right)

This subgroup consists of 31 members (only 19 are displayed on the public Results Page - to change this, see Footnote 1). Surname variants include O'Malley, O'Mally, Malley, Maley, Melia and Malia. Where mentioned, ancestral origins are most commonly Mayo.

Group 3a as it appears on the public Results Page
(click to enlarge)

Placing Group 3a on the Tree of Mankind

The Block Tree diagram below illustrates where the group sits on the Tree of Mankind. The SNP marker that appears to characterise this group is BY35730 - men called O'Malley (or variants) cluster together on this branch and are not seen on adjacent branches. Thus this forms a distinct branch on the Tree of Mankind. There are a few non-O'Malley names also on the branch (i.e. Donaho, Burke) and these are probably the result of Surname or DNA Switches that happened at some stage in the last 1000 years on the Direct Male Lines of the participants concerned.

Group 3a falls under the over-arching branch BY35730 (a 4-SNP block)
(click to enlarge)

Using SNP Counting (of the SNPs in the left-hand column), crude estimates for the TMRCA (Time to Most Recent Common Ancestor) of all men who sit on this branch is (approximately) ... 12 SNPs x 80 years per SNP = 960 years before present, subtracted from 1950 = 990 AD ... so about 1000 years ago.

This imprecise estimate occurs around the time of the introduction of surnames in Ireland and is consistent with the idea that Group 3a are descendants of a single progenitor who introduced the O'Malley surname around this time, which in turn flourished to the extent that there are surviving descendant lines living today.

Estimated dates of emergence of O and Mac surnames - combined dataset

The Importance of Big Y data

The Block Tree is based on SNP data generated by the Big Y test. As mentioned in a recent post, 42 project members have already done the Big Y test and this is making a big difference to the project, which is beset by "chance matches" due to Convergence (a known problem in the M222 portion of the Tree of Mankind), which in turn makes it very difficult to group participants accurately (especially in the Group 3 subgroups). The specific benefits of Big Y testing include:
  1. accurate grouping of project members
  2. precise placement of participants on the Tree of Mankind
  3. delineating the branching structure within groups (and thus providing a better indication of how close or distant the connection is between different group members)
  4. TMRCA estimates for different branches within the group
In Group 3a, SNP data has identified 4 distinct branches ... so far. More will follow as more group members undertake the Big Y test. Some of these branches may turn out to be well-known branches of the wider O'Malley clan (e.g. the Kilmilkin O'Malley's). As new Big Y results come in, they may create entirely new branches below BY35730, or alternatively may split existing branches into two or more additional sub-branches. 

The TMRCA estimates (based on SNP Counting) for each of the existing sub-branches are as follows:
  • BY35730 ... 12 SNPs back to TMRCA = [1950 - (12 x 80)] = 990 AD ... about 1000 AD
  • BY35759 ... 7 SNPs back to TMRCA = [1950 - (7 x 80)] = 1390 AD ... about 1400 AD
  • FT86146 ... 6 SNPs back to TMRCA = [1950 - (6 x 80)] = 1450 AD ... about 1450 AD
  • FT145889 ... 2 SNPs back to TMRCA = [1950 - (2 x 80)] = 1790 AD ... about 1800 AD

This demonstrates that most of the members of the group are very distantly related. This is not surprising given that the surname has been around for about 1000 years and many different descendant lines have emerged over this time, many surviving to the present day. 

It is also worth remembering that Irish records tend to dry up as you go back past 1800 and this is where many people have their Irish Brick Walls. So it may not be possible to connect the members of Group 3a other than through DNA. This is the main reason why we started the Extensive Lineage Project which aims to recruit O'Malley's with extensive direct male line pedigrees that go back into the 1600s and earlier. A close SNP match to any of these particular participants may allow people to piggyback onto these extensive lineages and move their own O'Malley research back several generations.

It will be interesting to see how the branching structure of the group evolves as more people join the project and do Big Y testing.

Adding non-Big Y test-takers to the Tree

Another important point to make is that only 12 of the 31 members of Group 3a appear in the Block Tree (i.e. only the ones who have done the Big Y test). Nevertheless, it is possible to confidently add some of the non-Big Y tested group members to the overall "genetic tree" for the Group 3a O'Malley's:
  • several group members have not done the Big Y but have cousins within the group who have done it. These known cousins are highlighted in yellow in the diagram below.
  • in addition, several group members share a similar USP (Unique STR Pattern) i.e. the same values on specific STR markers. This suggests that if they did Big Y testing, they would discover that they share a specific SNP marker unique to their particular branch.
As a result, it has been possible to identify 2 additional potential branches within the group (the red & orange branches below) and to add 27 of the 31 members to one of these branches (with a reasonable level of confidence). Further Big Y testing will reveal 1) whether or not these additional branches have been accurately identified; and 2) where they sit on the "genetic family tree" in relation to the other sub-branches within Group 3a. 

All Group 3a members - all but 4 could be allocated to one of 6 branches
Note: Privacy settings need to be adjusted for those redacted (see Footnote 1).
Common ancestors highlighted in yellow.
Red & Orange branches based on USP (Unique STR Patterns) - see below
(click to enlarge)
There is also a chance that these additional branches (red & orange) may in fact be new subgroups that are more than 1000 years old. As discussed previously, 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 genetic groups. If it turns out that the red and orange branches are more than 1000 years old, it is therefore likely that they don't share the same origin for their O'Malley surname as the rest of Group 3a. In these circumstances, they will be separated out from Group 3a and form their own specific subgroups (e.g. Groups 3g & 3h). More Big Y tests are needed to address this question ... and the results of someone in the red branch should be available in the next 4-8 weeks.

The Unique STR Pattern (USP) for the red & orange groups (values in bold):
Red branch = 10, 9, 15, 16, 12, 36, 36 in rows 2-4 (strong signal: 7-marker USP)
Orange Branch has 3 potential sub-branches:
a) 6-marker USP in rows 5-6 (strong signal) ... 13, 29, 18, 38, 39, 11
b) 8-marker USP in rows 7-8 (strong signal) ... 13, 29, 18, 14, 29, 17, 18, 38, 39
c) 2-marker USP in rows 9-10 (very weak signal) ... 13, 18

Why is Group 3a the most likely contender?

There is no single piece of evidence that suggests that Group 3a members are descendants of the original O'Malley's of Murrisk & Burrishoole. On the contrary, it is the totality of various strands of evidence that point to the conclusion that this particular genetic group of all the groups within the O'Malley DNA Project is the most likely candidate.

Points to consider include the following:
  1. With 31 members, Group 3a represents 39% (31/79) of the YDNA-tested project membership (this excludes the Other Surname group) and is thus the largest group within the project. The O'Malley's were an influential clan with a long-standing history. It would be expected that such a successful clan would leave quite a large genetic footprint behind them and have many descendants surviving to the present day. Smaller clans would be at risk of dying out. Thus the sheer dominance of Group 3a makes it a prime contender.
  2. The most frequently cited ancestral origins for Group 3a members is Mayo, the ancestral homeland of the O'Malley's.
  3. TMRCA estimates for Group 3a approximate 1000 AD which is close to when surnames arose in Ireland. This makes Group 3a the oldest genetic group within the project and suggests that members of this group have evaded the risk of a Surname or DNA Switch over the past 1000 years since the emergence of the surname.
  4. The SNP signature associated with Group 3a (M222) is consistent with the ancient genealogies for the O'Malley's of Murrisk & Burrishoole which document their descent from the forbears of Niall of the Nine Hostages (see previous post).
Therefore, as the dominant group within the project, with roots in Mayo, and with a DNA signature that is consistent with the ancient genealogies, Group 3a members are likely to be descendants of the O'Malley's of Murrisk & Burrishoole. As such, they would also be directly related to Grace O'Malley and it is hoped that in time we will be able to establish the specific SNP marker that her Direct Male Line is likely to have carried.

As more people join the FTDNA database and do Big Y testing, the genetic signatures associated with related clans (e.g. Brady, O'Connor, O'Flaherty, O'Reilly, O'Rourke, etc) will emerge and this may provide additional evidence that Group 3a represents the descendants of the O'Malley's of Murrisk & Burrishoole.

Maurice Gleeson
June 2021


Footnotes, Resources & Links

[1] Your Privacy settings may be preventing your anonymous results from appearing on the public Results Page. To change this, simply do the following:
  1. log on to your FTDNA account, 
  2. click on your name (top right), 
  3. then Account Settings, 
  4. then Project Preferences, 
  5. then scroll down to the Project Sharing section
  6. and beside Group Project Profile, move the slider to the ON position (this will show your kit number, surname & MDKA on the public Results Page, but not your full name).







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