Description of the Group
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| The 10 members of Group 2 with their MDKAs (Most Distant Known Ancestors) (click to enlarge) |
Group members have tested two types of Y-DNA marker - STR markers and SNP markers. The results of each type of test allow us to draw conclusions about how closely group members are related to each other, how old the group is overall, and the deeper origins of the group.
Y-STR Results
The group is fairly tight-knit and there are no big Genetic Distances between group members. This suggests that they are all relatively closely related and probably share a common ancestor within the last several hundred years (say since 1600).
Pedigrees go back to the late 1700s (1780 is the earliest). The largest TiP Report scores [1] between the various group members suggest that the MRCA (Most Recent Common Ancestor) for the entire group was born about 1830 (50% probability level) or 1650 (95% probability level). So taking the pedigree information and TiP Report information together, the MRCA for this group was probably born some time between 1650 and 1780 (assuming the average year of birth of group members is 1950, and assuming 30 years per generation). Thus the group is about 300 years old.
Consequently, there is a gap of about 700 years back to the origins of the surname for this group (assuming it arose about 1000 AD). Was there an SDS (Surname or DNA Switch) during this time period? The chances are about 30%. [2] Consequently, there is about a 70% chance that the O'Malley surname has been associated with the genetic signature for Group 2 since the time when surnames were founded in Ireland (about 1000 AD). And this suggests that this group arose independently of the O'Malley's of Mayo.
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| STR marker values for the 10 group members showing relatively few mutations (in blue/violet or pink) (click to enlarge) |
Pedigrees go back to the late 1700s (1780 is the earliest). The largest TiP Report scores [1] between the various group members suggest that the MRCA (Most Recent Common Ancestor) for the entire group was born about 1830 (50% probability level) or 1650 (95% probability level). So taking the pedigree information and TiP Report information together, the MRCA for this group was probably born some time between 1650 and 1780 (assuming the average year of birth of group members is 1950, and assuming 30 years per generation). Thus the group is about 300 years old.
Consequently, there is a gap of about 700 years back to the origins of the surname for this group (assuming it arose about 1000 AD). Was there an SDS (Surname or DNA Switch) during this time period? The chances are about 30%. [2] Consequently, there is about a 70% chance that the O'Malley surname has been associated with the genetic signature for Group 2 since the time when surnames were founded in Ireland (about 1000 AD). And this suggests that this group arose independently of the O'Malley's of Mayo.
The connection between group members based on their genealogies and their Y-DNA data is summarised in the "best fit" family tree below (you may have to click to enlarge it and then save it in order to see the detail). The STR mutations indicate which members are likely to be more closely related to each other and fit well with the known genealogies. Of note, DOM-7121 & MOM-1630 share the same mutation on STR marker dys712 (22>23) which suggests that they are more closely related to each other than the rest of the group, and thus may share a common ancestor one or more generations above their respective MDKAs (Denis 1810 & Patrick 1798). We will return to this question in the section on autosomal DNA results below.
Y-SNP Results
According to the Big Tree analysis of the two Big Y testers, one has a unique / private SNP (DJOM-7319) and the other has no unique / private SNPs (GOM-0664). DC735 actually represents a 7-SNP Block. Thus we can estimate that it arose about 750 to 1100 years ago (allowing 100-150 years per SNP). This translates crudely to 900-1250 AD.
Autosomal DNA Results
The O'Malley DNA Project welcomes everyone who has had a DNA test (and not just those who have done a Y-DNA test, which can only be done by men, because only men have a Y chromosome).
Autosomal DNA (atDNA) can be useful in determining the relationship between people when the records run out. And in Ireland there are few records before 1800. We see this reflected in the pedigrees for the members of Group 2, which only go back as far as the early 1800s or late 1700s.
As mentioned at the very beginning of this article, five group members share the common ancestor Michael O'Malley (born c.1780); another 3 share Dennis O'Malley (born 1793); one goes back to Patrick O'Malley (born 1798), and the last one has Denis O'Malley (born about 1810) as his MDKA (Most Distant Known Ancestor). The question remains: how are these MDKA's related to each other?
We previously combined the known genealogies and the Y-STR data to generate a "best fit" family tree (also known as a Mutation History Tree, see diagram above) but what happens when we add atDNA to this diagram? Does it help us determine how the four MDKA's are related?
We mentioned above that two of the members shared a Y-STR mutation (namely dys712 22>23) which allows us to group them together as more closely related to each other than to the rest of the group. Let's call them Branch B and the others Branch A and Branch C, as illustrated in the revised "best fit" family tree below, which also includes the amount of atDNA shared between those members who have done the atDNA test (i.e. Family Finder). I have renamed the various branch members A1, A2, A3, etc for ease of reference.
Branch A
A1 and A5 are 3rd cousins once removed (3C1R) according to their genealogies. They should therefore share an average of 48 cM (range 0-173 cM). They in fact share 153 cM which is toward the high end for a 3C1R relationship (you can see the probabilities on the Shared cM Tool the DNAPainter website). This suggests that there may be a double-connection between their respective family trees (e.g. they are 3C1R via their O'Malley line and maybe 4th cousins via a second ancestral line).
Branch B
B1 shares 144 cM with B2. According to the Shared cM Tool, the most likely relationship for this amount of shared DNA is 2nd cousin once removed (2C1R). However, their genealogies indicate that they cannot be closer than 4th cousins via their respective O'Malley ancestral lines. And the probability of them being 4th cousins is <2% (according to the Shared cM Tool). So there is probably a double-connection between these two people. They may be 4th cousins on their O'Malley line, but 3rd cousins (for example) on some other ancestral line.
Branch C
C2 & C3 share 842 cM (as expected for 1st cousins).
C1 & C3 share 391 cM, which is towards the high end for 2nd cousins.
C1 & C2 share an unusually low amount of DNA (56cM) - we would have expected much more for a 2nd cousin relationship.
How closely are the different branches related?
Branch A members appear to be more closely related to B2 than B1 ... but there is no guarantee that this is via their O'Malley lines - it could be via some other ancestral line. The amount of DNA they share with B2 (108 & 91 cM) suggests a 2C1R or 3C relationship, but the known genealogies suggest at least a 4th cousin relationship. The probability of 4th cousins sharing 108 or 91 cM is less than 10% so there may be a second (non-O'Malley) connection between B2 and Branch A members.
Branch A members share no DNA with C1 - this suggests the relationship cannot be closer than 3C1R and is more likely to be 4th cousins (or more distant). They also share an average of 85 cM with C2 & C3 ([130+113+56+43)] / 4). This 85 cM suggests a 2C1R to 3C1R relationship but the known genealogies suggest the connection can be no closer than 4th cousins. The probability of a 4C relationship sharing 85 cM is 10% so this relationship is possible. Alternatively there may be a second connection somewhere in their respective family trees.
Branch B members do not share any atDNA with Branch C members C1 & C3 - they only share DNA with member C2 (42 & 60 cM). This amount of DNA is consistent with a 4th cousin relationship but it could also be due to a second connection within their trees.
So even though atDNA analysis can help to interpret the connections between branches, the ever present possibility of a second connection (or more) hinders interpretation. In addition, FTDNA calculates the amount of shared DNA in a slightly different way to other companies (it includes smaller segments that may be false positives). As a result, the total cM values at FTDNA are about 10-20% higher than at other companies. This may make some of the atDNA matches look more closely related than they actually are.
Adding additional atDNA data from other project members (especially women members) to the McGuire Chart above could shed further light on the connections and may allow for more accurate estimates of how the four MDKAs are related. And it might be possible to use Triangulated Segments to help distinguish between O'Malley atDNA and atDNA passed down for a second common ancestor (but that is a big job requiring a lot more people to contribute their atDNA data).
Conclusions
The common ancestor for Group 2 was born some time around 1650 to 1750 in county Limerick (most likely).
The group has been in the Limerick area going back 1000 years or more, and descends genetically from the Dal gCais.
It is quite possible that the members of Group 2 are descendants of the O'Malley's of Tuath Luimnigh.
The connection between the four identified MDKAs remains elusive. Interpretation of atDNA data is plagued by the possibility of second connections between the project members.
Next Steps
In order to establish that the group has carried the O'Malley name since surnames were first founded (about 1000 AD), it will be important to Y-DNA test descendants of more distant branches of the family ... if they exist - they may have died out or daughtered out. Ideally we need to test O'Malley's whose MRCA with the rest of the group is 800-1000 years ago.
How can we establish the nature of the connection between the four identified MDKAs? There are several options available in this kind of situation but not all of them will help here:
As more people join the project and undertake more specialised DNA testing, some of these questions will be answered.
Footnotes & Sources
[1] the TiP Report score is an estimate of the probability that two people share a common ancestor within a certain number of generations. The midpoint score (50% probability) and 95% probability score are the most useful of the estimates. You can get the TiP Report score for any of your Y-DNA matches by clicking on the orange TiP icon underneath the name of each match in your list of matches.
[2] the risk of an SDS (Surname or DNA Switch) is calculated thus:
[3] A SNP Progression is simply the sequence of SNP markers that characterises each branching point on the Tree of Mankind, starting "upstream" at the level of the Haplogroup (R in this case) and progressing all the way "downstream" (i.e. towards the present day) to the Terminal SNP. Comparing SNP Progressions helps us see exactly where each terminal SNP sits on the Tree of Mankind relative to all the other SNPs.
[4] Dennis M Wright, 2009. A Set of Distinctive Marker Values defines a Y-STR Signature for Gaelic Dalcassian families. Journal of Genetic Genealogy, 5(1):1-7. Available at http://www.jogg.info/pages/51/files/Wright.pdf
[5] Surname Distribution Maps for Ireland can be found on several websites:
[6] There are several sources for Surname Histories and the most useful are:
[7] Begley, John. The diocese of Limerick: Ancient and Medieval. Dublin: Browne & Nolan, 1906. Page 13. Available to download from http://www.askaboutireland.ie/reading-room/digital-book-collection/digital-books-by-subject/church-history/begley-the-diocese-of-lim/
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| Mutation History Tree for Group 2 showing where mutations occurred (yellow boxes are test-takers; Y111 = Y-DNA111 test, etc; SP = SNP Pack; BY = Big Y; SNPs in blue, STRs in red) (click to enlarge) |
Y-SNP Results
Two members have done the Big Y test and another 2 have done SNP Pack tests. These results confirm that group members have been correctly grouped together and also indicate that the SNP marker that defines this group is DC735. Nobody other than O'Malley's bears this SNP marker indicating that (currently) it is unique to the O'Malley's of Group 2 and probably defines this particular group.
The SNP Progression [3] for this group is as follows:
- R-P312/S116 > Z290 > L21/S145 > DF13 > ZZ10 > Z253 > Z2534 > BY25450 > FGC5618 > FGC5625 > L226 > FGC5660 > Z17669 > A10950 > DC29 > DC735
According to the Big Tree analysis of the two Big Y testers, one has a unique / private SNP (DJOM-7319) and the other has no unique / private SNPs (GOM-0664). DC735 actually represents a 7-SNP Block. Thus we can estimate that it arose about 750 to 1100 years ago (allowing 100-150 years per SNP). This translates crudely to 900-1250 AD.
We know from the pedigrees of the group members that their ancestry goes back to Limerick in the late 1700's but where were they before this? The SNP results give us further clues.
Firstly, Group 2 members test positive for the "upstream" SNP marker L226. This SNP marker is associated with the "tribe" of the Dal gCais (pronounced Doll Gosh). [4] This was a tribe/sept/clan that descended from a man called Cas (born 347 AD) whose 5x times great grandfather was Oilioll Olum, King of Munster (and therefore born about 150 AD). This sept rose to prominence in the south of Ireland and was centred around Clare, Limerick & northern Tipperary. One of its most famous sons was Brian Boru, first High King of Ireland, who was killed at the Battle of Clontarf in 1014. Thus Brian Boru would be a distant cousin of all members of Group 2.
The SNP results also allow us to place the O'Malley's of Group 2 on a specific branch of the Tree of Mankind. And from this we can see that the nearest genetic neighbours of Group 2 are people called Curry, O'Hara, Hehir, O'Loughlin, Griffin, McInerney, Slattery, O'Neill, McNamara, Davis, & FitzGerald (see screenshot from The Big Tree below). The common ancestor for all these people would have tested positive for the SNP markers DC29 & DC32 (which we can estimate to have arisen about 950-1300 years ago, and thus at or before the foundation of surnames).
We can also explore the relevant Haplogroup Projects (e.g. L226 Project) for other related surnames (i.e. who test positive for DC29) and some additional related surnames are identified: Nealy, Roche, James, O'Halloran, Hartigan, Cline, O'Brien, Corry, Slater, Slattery, Savage, Mack, Small, Gleason, Bryan, & Harris.
We can then explore the distribution of these surnames on Surname Distribution Maps [5] to see if there is a particular concentration of these surnames in one particular area ... and there is - the highest concentration of these genetically-related surnames is in the Clare / Limerick area, the traditional ancestral homeland of the Dal gCais.
Firstly, Group 2 members test positive for the "upstream" SNP marker L226. This SNP marker is associated with the "tribe" of the Dal gCais (pronounced Doll Gosh). [4] This was a tribe/sept/clan that descended from a man called Cas (born 347 AD) whose 5x times great grandfather was Oilioll Olum, King of Munster (and therefore born about 150 AD). This sept rose to prominence in the south of Ireland and was centred around Clare, Limerick & northern Tipperary. One of its most famous sons was Brian Boru, first High King of Ireland, who was killed at the Battle of Clontarf in 1014. Thus Brian Boru would be a distant cousin of all members of Group 2.
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| One of the earliest representations of Brian Boru from O'Connor's translation of Keating's "History of Ireland" 1723 (from https://dh.tcd.ie/clontarf/) |
The SNP results also allow us to place the O'Malley's of Group 2 on a specific branch of the Tree of Mankind. And from this we can see that the nearest genetic neighbours of Group 2 are people called Curry, O'Hara, Hehir, O'Loughlin, Griffin, McInerney, Slattery, O'Neill, McNamara, Davis, & FitzGerald (see screenshot from The Big Tree below). The common ancestor for all these people would have tested positive for the SNP markers DC29 & DC32 (which we can estimate to have arisen about 950-1300 years ago, and thus at or before the foundation of surnames).
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| The O'Malley's of Group 2 on The Big Tree (far right) (click to enlarge) |
We can also explore the relevant Haplogroup Projects (e.g. L226 Project) for other related surnames (i.e. who test positive for DC29) and some additional related surnames are identified: Nealy, Roche, James, O'Halloran, Hartigan, Cline, O'Brien, Corry, Slater, Slattery, Savage, Mack, Small, Gleason, Bryan, & Harris.
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| DC29+ surnames from the L226 Haplogroup Project |
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| Distribution of selected surnames genetically-related to Group 2 (maps based on Griffith's Valuation, mid-1800s, from https://www.swilson.info/sdist.php) (click to enlarge) |
So not only do the pedigrees of the individual group members go back to Limerick, but the deeper genetic origins of this group (i.e. pre-1000 AD) also go back to the same area. Thus we can be reasonably certain that Group 2 arose in the Limerick area some 1000-1500 years ago, and adopted the O'Malley surname some time between 1000 AD and about 1650-1750.
The history behind some of these related surnames helps explain the genetic association with this area, as many of the surnames are documented to have arisen there or nearby. The following are excerpts from O'Hart's Irish Pedigrees:
The last excerpt above states that there was an O'Malley sept in the region near Limerick city. Woulfe also states that O'Malley was "a Thomond family who were chiefs of Tuath Luimnigh, a district in the neighbourhood of the city of Limerick". [6]
In addition, the passage below is from Begley's The Diocese of Limerick: Ancient and Medieval (page 13). [7] This refers to a topographical poem written by O'Heerin (before 1420, the year he died) and translated by O'Donovan (and published in 1862). From this we can assume that the O'Malley's had a distinct and notable presence in Limerick in the 1300s at least, if not earlier.
I have not been able to locate any further information on this particular sept (so if anyone comes across anything, please leave a comment below).
It is entirely possible (if not likely) that the O'Malley's of Group 2 are the descendants of the O'Malley's of Tuath Luimnigh (pronounced Too-a Lim-nee).
The history behind some of these related surnames helps explain the genetic association with this area, as many of the surnames are documented to have arisen there or nearby. The following are excerpts from O'Hart's Irish Pedigrees:
- 5. O'Haichir (or O'Hehir), chief of Hy-Flancha and Hy-Cormac, districts in the barony of Islands; and (according to O'Halloran) of Callan, in the county Clare.
- 8. MacConmara or MacNamara (literally "a warrior of the sea") was chief of the territory of Clan Caisin, now the barony of Tullagh, in the county Clare The Macnamaras were also sometimes styled chiefs of Clan Cuilean, which was the tribe name of the family; derived from Cuilean, one of their chiefs in the eighth century. This ancient family held the high and honourable office of hereditary marshals of Thomond.
- 10. O'Loughlin, chief of Burren, now the barony of Burren, county Clare which was sometimes called Eastern Corcomroe. The O'Loghlins and O'Connors here mentioned were of the same descent: namely, a branch of the Clan na Rory, descended from the ancient kings of Ulster of the race of Ir.
- 12. MacEneiry, [MG: McInerney?] chiefs of Corca Muiceadha, also called Conaill Uachtarach, now the barony of Upper Conello, in the county Limerick. The MacEneirys were descended from Mahoun, king of Munster, and brother of Brian Boru; and had their chief residence at Castletown MacEneiry.
- 14. O'Cullen, O'Kenealy [MG: maybe abbreviated to Nealy], and O'Sheehan, were chiefs in the baronies of Conello, county Limerick.
- 15. O'Macassa (Macassey, and Maxey) [MG: maybe abbreviated to Mack], chief of Corca Oiche: and O'Bergin, chief of Hy-Rossa, districts in the county Limerick.
- 21. O'Kenealy [MG: maybe abbreviated to Nealy], chief of Eoganacht Grian Guara, a district comprising parts of the baronies of Coshma and Small County in Limerick.
- 23. O'Caolidh or O'Keely, and O'Malley are given as chiefs of Tua Luimnidh or "the district about Limerick."
The last excerpt above states that there was an O'Malley sept in the region near Limerick city. Woulfe also states that O'Malley was "a Thomond family who were chiefs of Tuath Luimnigh, a district in the neighbourhood of the city of Limerick". [6]
In addition, the passage below is from Begley's The Diocese of Limerick: Ancient and Medieval (page 13). [7] This refers to a topographical poem written by O'Heerin (before 1420, the year he died) and translated by O'Donovan (and published in 1862). From this we can assume that the O'Malley's had a distinct and notable presence in Limerick in the 1300s at least, if not earlier.
 |
| The O'Malley territory included the parish of Knocknagaul (due south of Limerick city) |
I have not been able to locate any further information on this particular sept (so if anyone comes across anything, please leave a comment below).
It is entirely possible (if not likely) that the O'Malley's of Group 2 are the descendants of the O'Malley's of Tuath Luimnigh (pronounced Too-a Lim-nee).
Autosomal DNA Results
The O'Malley DNA Project welcomes everyone who has had a DNA test (and not just those who have done a Y-DNA test, which can only be done by men, because only men have a Y chromosome).
Autosomal DNA (atDNA) can be useful in determining the relationship between people when the records run out. And in Ireland there are few records before 1800. We see this reflected in the pedigrees for the members of Group 2, which only go back as far as the early 1800s or late 1700s.
As mentioned at the very beginning of this article, five group members share the common ancestor Michael O'Malley (born c.1780); another 3 share Dennis O'Malley (born 1793); one goes back to Patrick O'Malley (born 1798), and the last one has Denis O'Malley (born about 1810) as his MDKA (Most Distant Known Ancestor). The question remains: how are these MDKA's related to each other?
We previously combined the known genealogies and the Y-STR data to generate a "best fit" family tree (also known as a Mutation History Tree, see diagram above) but what happens when we add atDNA to this diagram? Does it help us determine how the four MDKA's are related?
We mentioned above that two of the members shared a Y-STR mutation (namely dys712 22>23) which allows us to group them together as more closely related to each other than to the rest of the group. Let's call them Branch B and the others Branch A and Branch C, as illustrated in the revised "best fit" family tree below, which also includes the amount of atDNA shared between those members who have done the atDNA test (i.e. Family Finder). I have renamed the various branch members A1, A2, A3, etc for ease of reference.
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| McGuire Chart for those men who have also done atDNA testing (numbers represent amount of DNA shared in cM) (click to enlarge) |
Branch A
A1 and A5 are 3rd cousins once removed (3C1R) according to their genealogies. They should therefore share an average of 48 cM (range 0-173 cM). They in fact share 153 cM which is toward the high end for a 3C1R relationship (you can see the probabilities on the Shared cM Tool the DNAPainter website). This suggests that there may be a double-connection between their respective family trees (e.g. they are 3C1R via their O'Malley line and maybe 4th cousins via a second ancestral line).
Branch B
B1 shares 144 cM with B2. According to the Shared cM Tool, the most likely relationship for this amount of shared DNA is 2nd cousin once removed (2C1R). However, their genealogies indicate that they cannot be closer than 4th cousins via their respective O'Malley ancestral lines. And the probability of them being 4th cousins is <2% (according to the Shared cM Tool). So there is probably a double-connection between these two people. They may be 4th cousins on their O'Malley line, but 3rd cousins (for example) on some other ancestral line.
Branch C
C2 & C3 share 842 cM (as expected for 1st cousins).
C1 & C3 share 391 cM, which is towards the high end for 2nd cousins.
C1 & C2 share an unusually low amount of DNA (56cM) - we would have expected much more for a 2nd cousin relationship.
How closely are the different branches related?
Branch A members appear to be more closely related to B2 than B1 ... but there is no guarantee that this is via their O'Malley lines - it could be via some other ancestral line. The amount of DNA they share with B2 (108 & 91 cM) suggests a 2C1R or 3C relationship, but the known genealogies suggest at least a 4th cousin relationship. The probability of 4th cousins sharing 108 or 91 cM is less than 10% so there may be a second (non-O'Malley) connection between B2 and Branch A members.
Branch A members share no DNA with C1 - this suggests the relationship cannot be closer than 3C1R and is more likely to be 4th cousins (or more distant). They also share an average of 85 cM with C2 & C3 ([130+113+56+43)] / 4). This 85 cM suggests a 2C1R to 3C1R relationship but the known genealogies suggest the connection can be no closer than 4th cousins. The probability of a 4C relationship sharing 85 cM is 10% so this relationship is possible. Alternatively there may be a second connection somewhere in their respective family trees.
Branch B members do not share any atDNA with Branch C members C1 & C3 - they only share DNA with member C2 (42 & 60 cM). This amount of DNA is consistent with a 4th cousin relationship but it could also be due to a second connection within their trees.
So even though atDNA analysis can help to interpret the connections between branches, the ever present possibility of a second connection (or more) hinders interpretation. In addition, FTDNA calculates the amount of shared DNA in a slightly different way to other companies (it includes smaller segments that may be false positives). As a result, the total cM values at FTDNA are about 10-20% higher than at other companies. This may make some of the atDNA matches look more closely related than they actually are.
Adding additional atDNA data from other project members (especially women members) to the McGuire Chart above could shed further light on the connections and may allow for more accurate estimates of how the four MDKAs are related. And it might be possible to use Triangulated Segments to help distinguish between O'Malley atDNA and atDNA passed down for a second common ancestor (but that is a big job requiring a lot more people to contribute their atDNA data).
Conclusions
The common ancestor for Group 2 was born some time around 1650 to 1750 in county Limerick (most likely).
The group has been in the Limerick area going back 1000 years or more, and descends genetically from the Dal gCais.
It is quite possible that the members of Group 2 are descendants of the O'Malley's of Tuath Luimnigh.
The connection between the four identified MDKAs remains elusive. Interpretation of atDNA data is plagued by the possibility of second connections between the project members.
Next Steps
In order to establish that the group has carried the O'Malley name since surnames were first founded (about 1000 AD), it will be important to Y-DNA test descendants of more distant branches of the family ... if they exist - they may have died out or daughtered out. Ideally we need to test O'Malley's whose MRCA with the rest of the group is 800-1000 years ago.
How can we establish the nature of the connection between the four identified MDKAs? There are several options available in this kind of situation but not all of them will help here:
- Upgrading to 111 markers would be of limited benefit because sufficient numbers of people from each Branch have already upgraded. It would help confirm the mutations already identified for each of the three branches, and clarify which are shared mutations and which are unique mutations.
- Upgrading everyone to the Big Y-700 would help as this would allow us to compare 700 STR markers and would help us generate a more detailed Mutation History Tree for the group (i.e. the "best fit" family tree). Both Branch B members should test, and the Branch A and C members who have tested should upgrade to Big-Y-700.
- Adding more atDNA data to the McGuire chart above would also help, but second connections within trees would have to be identified and (if possible) shared cM values adjusted accordingly (but this will require speculation so caution is advised).
As more people join the project and undertake more specialised DNA testing, some of these questions will be answered.
Maurice Gleeson
June 2019
Footnotes & Sources
[1] the TiP Report score is an estimate of the probability that two people share a common ancestor within a certain number of generations. The midpoint score (50% probability) and 95% probability score are the most useful of the estimates. You can get the TiP Report score for any of your Y-DNA matches by clicking on the orange TiP icon underneath the name of each match in your list of matches.
[2] the risk of an SDS (Surname or DNA Switch) is calculated thus:
- 650 years represents approximately 22 generations (allowing 30 years per generation)
- The rate of SDS's is about 1-2% per generation (based on several published studies)
- The probability of having no SDS's in 22 generations given a 1% SDS probability per generation is 0.99^22 = 0.8016 (80%). So the probability of having at least one SDS is 1 - 0.8016, that is 20%.
- The probability of having no SDS's in 22 generations given a 2% SDS probability per generation is 0.98^22 = 0.6412 (64%). So the probability of having at least one SDS is 1 - 0.6412, that is 36%.
- So there is a 20% to 36% chance that there was a switch in the surname or the DNA for Group 2 during the 650 year period between the foundation of surnames (1000 AD) and the MRCA for the group (born between 1650 & 1780 approximately).
[3] A SNP Progression is simply the sequence of SNP markers that characterises each branching point on the Tree of Mankind, starting "upstream" at the level of the Haplogroup (R in this case) and progressing all the way "downstream" (i.e. towards the present day) to the Terminal SNP. Comparing SNP Progressions helps us see exactly where each terminal SNP sits on the Tree of Mankind relative to all the other SNPs.
[4] Dennis M Wright, 2009. A Set of Distinctive Marker Values defines a Y-STR Signature for Gaelic Dalcassian families. Journal of Genetic Genealogy, 5(1):1-7. Available at http://www.jogg.info/pages/51/files/Wright.pdf
[5] Surname Distribution Maps for Ireland can be found on several websites:
- John Grenham's website (www.johngrenham.com) has maps based on Griffith's Valuation (from the mid-1800s)
- so too does Shane Wilson's website (https://www.swilson.info/sdist.php)
- Barry Griffin's website has maps based on the 1901 & 1911 censuses, including maps identifying just the farmers (whose families are likely to have held the land for several generations at least).
[6] There are several sources for Surname Histories and the most useful are:
- Woulfe, Patrick. Sloinnte Gaedheal is Gall: Irish Names and Surnames, collected and edited with explanatory and historical notes (1923). ... available at https://www.libraryireland.com/names/contents.php
- O'Hart, John. Irish pedigrees; or, The origin and stem of the Irish nation (1892, 5th edition) ... available at https://www.libraryireland.com/Pedigrees1/title.php
- MacLysaght, Edward. Several books but unfortunately not available online:
The Surnames of Ireland. 1957 (sixth edition 1991)
Irish Families. Their Names, Arms and Origins. 1957 (fourth edition 1985)
More Irish Families. 1970 (first paperback edition 1996, incorporating Supplement to Irish Families, 1964)
[7] Begley, John. The diocese of Limerick: Ancient and Medieval. Dublin: Browne & Nolan, 1906. Page 13. Available to download from http://www.askaboutireland.ie/reading-room/digital-book-collection/digital-books-by-subject/church-history/begley-the-diocese-of-lim/
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