DNA and the Sexton families of western County Clare, based particularly in Kilmurry-Ibrickan parish

It has long been assumed that due to the large number of Sextons families appearing in the surviving records of Co. Clare, Ireland that the Sexton name must have been established in the county for a great many generations, and that due to a lack of surviving documents to prove relationships prior to around the 1820’s, working out whether the numerous Sexton families shared any family connections to each other would never be possible.

While that may still prove the case for those Sexton families based in eastern Co. Clare (points around Ennis and to the east), for the Sexton families in western Co. Clare the situation is now proving to be somewhat different. There is now strong evidence to suggest that not only are a great many of (and quite possibly all of) the various Sexton families in western Co. Clare related, but that they actually share a common ancestor as recently as the mid to late eighteenth century – say 1750 to 1790.

Close examination of the surviving nineteenth century records (parish, Griffith Report, Tithe returns, etc), indicates that for the Sexton surname it is possible to treat Co. Clare as being in three distinct parts.

• The first part of Co. Clare takes in the eastern half of the county between the eastern border and a line drawn north-south through Ennis (or just to west of Ennis), an area that contains a lot of Sexton families spread out over quite a number of parishes most especially in the southeast where there is indications of connections stretching over the border into the counties of Tipperary and Limerick.
• The second part of Co. Clare is a central section situated between the north-south line through Ennis and a similar line further westward that goes roughly through The Hand. In this section the Sexton name is only extremely rarely to be found and in most parishes not at all. 
• The final part is those areas of Co. Clare that lie westward of the north-south line through The Hand. In this part of Co. Clare the Sexton surname is again relatively common – though in smaller numbers than eastern Co. Clare – and most of the Sexton families are clustered in and closely around Kilmurry-Ibrickan parish. 

Because the Sexton name was relatively common in Kilmurry-Ibrickan and surrounding parishes, there are considerable numbers of people who can trace their family lineage back to a Sexton family in the parish in the early to mid 1800s but then, like so much Irish research, the search for earlier ancestors then grinds to a halt due to lack of surviving records.

Recently, not only has accessing Irish records from a distance become easier but DNA testing - the next big tool in genealogical research - is now readily available through various genealogical companies at reasonable prices. Already it is proving a very valuable research tool, opening up new lines of research that were previously not possible or at most only theorised about without any firm support.

With reference to the Sexton surname, over the last year or two some 22 people from three different countries (USA, Australia and of course Ireland) who have had DNA tests done have now been confirmed as cousins as per the grid below. The 22 people include several pairs of siblings and parents/children, and the numbers shown in the grid are the estimated number of generations to the MRCA (Most Recent Common Ancestor) for any two people listed. The colour coding is to make it easier to see where there is a roughly similar level of relationship between any two people.

• A MCRA relationship of exactly one generation indicates a parent/child relationship. - Where the estimate to MCRA is greater than 1 and less than 2 generations this involves close relatives such as siblings (including half-siblings). 
• Where the estimate to MCRA is greater than 2 and less than 4 generations it involves two living people who are known documented cousins – typically no more than around 3rd cousins in distance. 
• When the estimate to MCRA is in the range of 4-6, the cousin relationship is typically at least fourth cousins (sharing a 3xgreat-grandparent) in distance if not even more so. In the case of Ireland this typically puts the MCRA back before the start of surviving parish records. 
• The highest numbers (6s and 7s) indicate a relative small amount of shared DNA between two individuals. NOTE: this does not automatically mean the relationship is massively more distant – simply that the two individuals share relatively much less common DNA than those with closer estimates of MCRA.

The majority of relationships in the grid above are more distant relationships, being estimated in the four to five generation range, indicating a common ancestor around the level of perhaps the 4xgreat-grandparent or 5xgreat-grandparent.

While the highest numbers (6’s and 7’s) for estimates to the MRCA (Most Recent Common Ancestor) would at first glance indicate the connection must be much further back this is not necessarily the case. It is worth noting that an estimate to the MCRA is just that - an estimate - and it can vary quite a lot depending on the distance of the relationships and the mix of shared DNA that has been inherited by the two individuals being compared.

This can be clearly demonstrated by examining more closely two different pairs of siblings that included in the grid above: Peter Mckay and his sister Helen McKay versus Kevin J. O’Brien and his brother Edward P. O’Brien. Taking their respective MCRA estimates from the grid above and displaying them together for easy comparison, we get the following:

	Kevin O’Brien	Edward O’Brien
Peter McKay	4.6	4.8
Helen McKay	7.0	7.4

The initial expectation might be to assume that any pair of siblings would have very similar estimates to a MCRA with another related pair of siblings. In the example above (and born out by the full comparison grid earlier) Kevin and Edward while showing as different to each of Peter and Helen, the differences between Kevin and Edward to the same person are relatively small. However it can clearly be seen that Peter and Helen, though brother and sister, received significantly different mixes of DNA as evidence by the large differences in how each of them compares to the O’Brien brothers.

The explanation for the variance is the fact that every person receives a random mix of DNA from both their parents and as a result even full siblings can have significantly differing mixes of inherited common DNA. This also explains why in some cases one sibling can show a match to another person while a second sibling does not match at all.

Given that all of the 22 people in the main relationship grid can trace their ancestry back to Kilmurry-Ibrickan parish in western Co. Clare, the evidence that they are all related is by itself perhaps not overly surprising. Where things become very interesting is that it turns out that the ONLY family surname shared in common in the known ancestry of 21 of the 22 known cousins is the Sexton surname. Equally importantly, in every case that Sexton ancestry can be traced back to the area around Kilmurry-Ibrickan parish.

The 22nd family (that of Martin Murphy) has no documented Sexton ancestor, but the Sexton ancestor must exist at the start of the lineage, as there is no other plausible explanation in terms of ancestral lines to explain so many matches with other known Sexton descendants. Furthermore, there is known crossover in this line with the same O’Brien family who also marries into other parts of the Sextons, and as there is a strong practice of marrying spouses from closely related families by these Kilmurry-Ibrickan families this provides indirect support for presuming a Sexton ancestor for Martin Murphy.

The various documented or known lines of descent are as follows (Sexton direct line of descent shown by family surname in capital letters). The people listed in each generation should not be treated as direct contemporaries since the earliest generation (number 1) spans a wide time frame with estimated births from the 1770s through to the 1820s. However the last listed person in each list is currently living, albeit with ages ranging from twenties through to early eighties, in the USA, Australia and Ireland.

	Lineage 1	Lineage 2	Lineage 3
Gen 1	Luke Darcy & Anne? SEXTON	Luke Darcy & Anne? SEXTON (probably parents of)	Luke Darcy & Anne? SEXTON (probably parents of)
2	Patrick (Luke) DARCY & Bridget Griffey	James DARCY & Bridget ??	James DARCY & Bridget ??
3	Patrick Bried Ban DARCY & Elizabeth Looney	John DARCY & Catherine Talty	John DARCY & Catherine Talty
4	Patrick Darcy & Margaret DARCY	Michael DARCY & Catherine Malley	Michael DARCY & Catherine Malley
5	Joseph DARCY & Masie A. Dickenson	James DARCY & Susan Callinan	James DARCY & Susan Callinan
6	Michael D. DARCY	Paddy DARCY	Michael DARCY & Lucy O’Hanolon
7			Ita DARCY

	Lineage 4	Lineage 5	Lineage 6
1	Luke Darcy & Anne? SEXTON (probably parents of)	Male O’Brien & Female SEXTON	Francis SEXTON & Bridget ??
2	James DARCY & Bridget ??	Synon Haneen & Bridget O’BRIEN	Francis SEXTON & Johanna (Susan) Sexton
3	John DARCY & Catherine Talty	Sinon HANNON & Winifred Millican	John SEXTON & Jane Hogan
4	John DARCY & Catherine O’Sullivan	John Neylon & Ellen HANNON	William Alfred Mason & Elizabeth SEXTON
5	Hugh Talty & Margaret DARCY	Martin Joseph Murphy & Mary Ann NEYLON	Norman Alex’der Reid & Kathleen Joyce MASON
6	Patrick Crowley & Mary TALTY	Martin MURPHY	Judith REID
7	J. Bernard CROWLEY

	Lineage 7	Lineage 8	Lineage 9
1	Francis SEXTON & Bridget ??	Francis SEXTON & Bridget ??	Patrick SEXTON & Margaret Boyle
2	Francis SEXTON & Johanna (Susan) Sexton	Francis SEXTON & Johanna (Susan) Sexton	John SEXTON & Elicia Gorman
3	John SEXTON & Jane Hogan	John SEXTON & Jane Hogan	George Joseph SEXTON & Inez Lois West
4	William Alfred Mason & Elizabeth SEXTON	William Alfred Mason & Elizabeth SEXTON	John West SEXTON & Mary Elaine Devine
5	Norman Alex’der Reid & Kathleen Joyce MASON	Barry John MASON &  ??	Daniel Sexton
6	John R. Hayes & Judith REID	Diane MASON (married ?? Houghton)
7	Susannah HAYES

	Lineage 10	Lineage 11	Lineage 12
Gen 1	Thomas SEXTON & (1st wife) Unknown	Thomas SEXTON & (2nd wife) Catherine Molony	Martin SEXTON & Mary Comerford
2	Paidrigan SEXTON & Mary Moroney	John SEXTON & Mary O’Connor	Henry SEXTON & Bridget Clancy
3	Patrick Laffey & Mary Jane SEXTON	Patrick SEXTON & Mary Downes	Martin J.A. SEXTON & Anne Greene
4	Lawrence E. LAFFEY & Henrietta A. Dishinger	Patrick SEXTON & Bridget Foudy	Joseph Kelly Kett & (Bridget) Teresa SEXTON
5	Robert L. LAFFEY & Mary Ellen Byrnes	Teresa SEXTON	Seamus Gerard Leyden & Mary Teresa KETT
6	Michael C. LAFFEY		Joe LEYDEN
7

	Lineage 13	Lineage 14	Lineage 15
Gen 1	Daniel Boland & Winifred SEXTON	Michael SEXTON & Margaret O’Brien	Michael SEXTON & Margaret O’Brien
2	Peter Sexton & Margaret BOLAND	Michael SEXTON & Honoria Gleeson	Michael SEXTON & Honoria Gleeson
3	Daniel SEXTON & Norah Downes	Thomas L. SEXTON & Mary Agnes Minto	Jeremiah J. SEXTON & Marguerite E. Pyle
4	John SEXTON & Anne Downes	John Thomas Lucas & Eileen Mary SEXTON	Jerimiah W’m SEXTON & Rita Mary Corboy
5	Brendan SEXTON	Jack Arthur McKay & Mary Agnes LUCAS	(siblings) Maureen SEXTON Peter J. SEXTON
6		(Siblings) Peter MCKAY Helen MCKAY
7

	Lineage 16	Lineage 17	Lineage 18
Gen 1	Peter SEXTON & Mary (Maura) O’Gorman	Peter SEXTON & Mary (Maura) O’Gorman	Peter SEXTON & Mary (Maura) O’Gorman
2	James SEXTON & Ann Marrinan	James SEXTON & Ann Marrinan	James SEXTON & Ann Marrinan
3	Thomas SEXTON & Margaret O’Halloran	Thomas SEXTON & Margaret O’Halloran	Thomas SEXTON & Margaret O’Halloran
4	James SEXTON & Nellie Conroy	James SEXTON & Nellie Conroy	James SEXTON & Nellie Conroy
5	James Francis SEXTON & Catherine Garrett	James Francis SEXTON & Mildred Hayden	James Francis SEXTON & Mildred Hayden
6	Kevin SEXTON (of Moyglass)	Raymond MILLER	Raymond MILLER & Pamela Roland
7			Peter Roland MILLER

	Lineage 19
Gen 1	John O’Halloran & Mary SEXTON
2	Stephen O’Brien & Margaret O’HALLORAN
3	John J. O’BRIEN & Mary Margaret Moroney
4	Edward Patrick O’BRIEN & Clara Dorothy Harrington
5	(siblings) Kevin J. O’BRIEN Edward P. O’BRIEN
6
7

While some of the above lines of descent show a common ancestor (due to two or more descendants having been DNA tested) there is no common ancestor that ties together all the lines that can be found in the documented paper trail or even via the surviving oral history in each of the families. Despite this, DNA testing confirms the relationship and as the above lineages show the common ancestor must surely have the surname of Sexton.

The other key point to take from the lineages shown above is that combined together, the various lines have at least eight different earliest known Sexton ancestors, almost all of whom have estimated birth years in the range of 1770-1790, making them contemporaries and since they share a common ancestor no more than 1-2 generations earlier are likely either all siblings or perhaps a mixture of siblings and nieces/nephews/children from the next generation.

Detailed comparison of every single Sexton related record surviving from the western edge of County Clare (most are in or near Kilmurry-Ibrickan) is still ongoing and has so far established that while there are significant numbers of Sextons in western Co. Clare from the around 1800 onwards, there are relatively few identifiable Sextons in the area in the prior period from the mid to very late 1700s. While one possible explanation for the lack of identifiable Sextons could be attributed to the small number of surviving records, the DNA results as described above suggest a more interesting likelihood.

The earliest known Sexton in the area is one Michael Sexton who was buried at Mountscott in 1806 (aged 66 years, so born circa 1740) by his widow Margaret Darcy Sexton. There is no record of Margaret Darcy Sexton’s death or burial, but it is plausible to believe she was likely similar in age (that is probably born no later than around 1750). As such they were likely married and having children by the early 1770s and this is consistent with there being around 20 known Sextons with birth years prior to 1795 (there are also several females Sextons whose ages at death place their births in that range but most of these are likely spouses of Michael & Margaret’s sons rather than children themselves).

It is worth noting that around half of these known Sextons with estimated birth years prior to 1795 feature as the head of one or more of the 19 lineages detailed above. Of the two or three females with estimated birth years prior to 1795, it seems likely that they are the wives of some of the early Sexton males, though at this time it is not possible to determine which probable wife goes with which potential husband.

There is currently no known evidence for any Sextons in western Co. Clare before say 1750 - although this could be due to nothing more than a lack of surviving records (including cemetery headstones). However it is also worth noting that oral family history passed down in some of the family lines detailed above does make the claim that all the Sextons in western Co. Clare are related and their earliest Sexton ancestor is thought to have arrived in the area in the mid 1700s.

That oral history is now looking much more plausible since the DNA evidence as demonstrated above is indeed supporting the argument that all the Sextons in the west of the county are likely to be related. There are multiple Sexton descendants who show as having a MCRA in the range of five to seven generations back. Michael Sexton (circa1740-1806) is the right age to have moved into western Co. Clare in the 1760s, and he is looking like he is an extremely strong candidate to be the MRCA for all the Sextons in the west of the county.

Given the wide prevalence of the Darcy surname in the Kilmurry-Ibrickan parish and surrounding areas, it seems likely Michael’s wife Margaret Darcy was a local girl he married after on arrival in the Kilmurry-Ibrickan area. The various first generations shown in the tables above are currently thought to be a mix of the children and grandchildren of Michael Sexton and wife Margaret Darcy, thus helping explain the variations estimated birth years for the Sexton first generation person and also the variations in estimated generations to the most recent common ancestor between the various lineages.

The main challenge now is trying to sort out the relatively large group of Sexton surname people in western Co. Clare and where they all fit in as probable grandchildren of Michael Sexton and Margaret Darcy – who were their respective fathers and mothers?

To help in that regard it would be great to hear from any other people who can trace their Sexton ancestry back to western County Clare, and in particular to Kilmurry-Ibrickan parish.

Peter McKay