Main Findings

The main findings that have emerged from the Clan Irwin Surname DNA Study so far are listed below:

1. The success of this Study is manifest by its steady growth nearly twenty years to over 600 members, so that it is now one of the 50 largest of over 10,000 surname DNA projects worldwide.  It is also one just seven surname projects in the Gold section of Tiger Walsh's Surname Hall of Fame for R1b Subclades.

2. Amongst those men now tested are descendants, direct or collateral, of the Lairds of Drum, Bonshaw and Castle Irvine, of the Dumfries, Ewesdale, Forfarshire, Perthshire, Newton,  Orkney, Shetland and Limerick branches of our surname, and of notable individuals including the American poet Washington Irving (1783-1859), the orator Rev. Edward Irving (1792-1834), and the mountaineer Sandy Irvine (1902-1924).   Representatives of the Cleuchhead, Castlederg, Lancaster Co., Augusta, and Westmoreland Co. lineages have also tested.  

3. About 5% of these testers, including senior representatives of all the long-established Scottish and Irish branches of the surname, were asked to participate in the Study to enable traditional genealogical relationships to be proved or disproved.  The remaining 95% of members have joined the study at the initiative of themselves or close family members, in the expectation that their tests will identify hitherto unsuspected relationships.

4. 95% of the testers have tested to 37 STR markers or more, and these usually tests suffice to identify from branch of the surname the tester is descended.  However testing to higher resolutions has generally been found to be less cost effective, and upgrading to 111 markers is not recommended without prior consultation with the Study Administrator.  Up to 838 STR markers are now available to individuals taking the newer BigY700 test, but these additional markers are of much less value than the more reliable SNP data and haplotree developments derived from BigY tests (see below). 

5. The geographic origins in the Old World of the paternal ancestry of nearly 90% of all testers have been ascertained.  Scottish origins predominate.

6. Some local spelling variants of the surname remain dominant within Great Britain (Irving in Dumfriesshire, Irvine elsewhere in Scotland, Urwin in Northumberland and Durham, Irwin elsewhere in England). However the spelling of the surname today, especially in Ireland and in the New World, has been shown to be a most unreliable indicator of the geographic origin of paternal ancestry.

7. To qualify for membership of one of the Study’s branches (aka genetic families), comparison of the tester’s STR signature with the modal signature of the branch must have a genetic distance of 7/37 or less.

8. Over 40 distinct branches using the surname and its spelling variants have been identified, each unrelated to one another during the surname era.   All but five of these branches have representatives today in North America. The number of distinct branches of our surname is now increasing very slowly, suggesting that few more large branches are still waiting to be "discovered". 

9. Nearly two-thirds of all the Study's testers are members of the "Border Irwin" branch, sharing a common ancestor who probably lived in Dumfriesshire on the Scottish Borders during the 14th century, although his name is unknown.  This branch includes testers representing the Irvines of Eskdale, the Irvings of Bonshaw and of Dumfries (all in Dumfriesshire), the Urwins of Durham and Northumberland, and the Irvines of Castle Irvine (Co. Fermanagh).  Some of these testers still live in the Borders today, some are descended from ancestors who migrated direct from there to America, but the majority now living in USA are descended from ancestors who probably migrated from the Borders to Ulster in the 17th century, and from Ireland to colonial America (typically to the Appalatian regions of PA, VA, NC, SC and GA) in the 18th century, typically for economic or religious reasons.  This proportion of testers sharing a single common ancestor within the surname era is much higher than found in most other Scottish surname DNA projects, and our Borders branch is probably the largest such branch in any Surname DNA project.  

10.  A curious feature of this large branch is that 30 testers have identical STR signatures to 37 markers (and 12 of which have identical signatures to 67 markers), and yet very few of them have been able to identify a genealogical relationship.  However these signatures have some differences in the 68-111 marker panel.  SNP tests now suggest that this apparent uniformity at 37 and 67 markers is probably due to convergence of STR markers, and so is misleading.  

11. Conversely this branch also has two brothers with a genetic distance of 2 in 25 markers.  This example illustrates the dangers of relying only on the STR signatures of two individual testers to identify a close relationship.  

12. All of the remaining Irwin branches in the Study are relatively small, the second largest being represented by only 16 testers.

13. Of these small branches, all of whose members now use the surname Irwin (or spelling variants), nearly half share the DNA signatures of other surnames, mostly from the Scottish/English border, implying some non-paternal event ("NPE") such as a young boy taking the name of his Irving stepfather, probably before the 17th century when many Irvings migrated to Ireland.

14. A further nine of these small branches have origins elsewhere in Scotland, including one from Drum in Aberdeenshire, one from Forfarshire, one from Perthshire, two from Orkney, and four from Shetland.  None of these branches are genetically related to the Borders branch, or to one another, within the surname era, and none are close matches with any other surname.  This suggests most are not NPEs but are descended from unrelated individuals who adopted the surname independently at an early date, possibly because they came from the town of Irvine in Ayrshire, which was an important port in medieval times. 

15. The specific finding that representatives of the families of Bonshaw and Drum do not share a common patrilineal ancestor during the surname era contradicts the popular tradition that the two lines were related in the 14th century through a paternal line.  However, although there is no supporting evidence, it remains possible that the two lines were related by some female line.

16. None of the testers share DNA signatures of the Carlyle, Dunbar, Hume or Robertson families whose traditions, like that of the Irvings, claim paternal descent from Crinan, the grandfather of King Duncan I of Scotland.  There is thus no DNA evidence to support this tradition, nor is there any DNA evidence (or any recognised documentary evidence) that the Irvings had royal ancestry through a paternal line.

17. It is nevertheless accepted that the probabilistic basis of genetic genealogy prevents dogmatic conclusions or legal proof. 

18. The origins of a further twelve small branches have not yet been determined; all are probably Scottish; some may be NPEs.

19. These findings are suggesting that even within Scotland the surname has plural origins, and are contradicting the tradition that all Scots bearing the surname had a single ancestor.

20. Ten other small branches appear to have origins unrelated to Scotland:  four apparently use anglicised versions of Gaelic surnames that originated in southern Ireland, two appear to be descended from the Dutch or German surname Arnwin, and one has African origins.

21. 5% of the members in the Study have clearly inherited the DNA signature of one of the Irwin branches but are no longer using the surname Irwin (or variant spelling).   The ancestries of these testers clearly include an NPE.  Probable circumstances, locations and approximate dates for some of these "events" have been identified.  

22. Only 6% of all members cannot (yet) be assigned to a branch family because they are singletons, apparently unrelated to any other tester.  Some of these will be NPEs.

23. So far there has been only limited success in identifying genealogical relationships within our various branches, but this is not surprising as only about 0.2% of the world's 100,000 adult males who today use the surname, however spelt, have undergone a yDNA test.  As new testers continue to join, and analysis methods improve, more relationships will be found.

24. The advent of yDNA tests such as single SNP tests, Pack tests and especially BigY tests, together with FTDNA's predicted haplogroups of members who have only taken STR tests, has enabled all of the Study's branches to be placed on a Clan Irwin haplotree (aka phylogenetic tree) which shows the descent from the "genetic Adam" of each branch, and hence all its members.

25. A few members of our Study have taken National Genographic's Geno2 test, but their test results have contributed little to our Study. 

26. Two attempts have been made to sub-divide our large Borders branch into sub-groups.  In 2011 the branch was tentatively divided into 14 sub-groups, each with identified by a distinctive STR signature which was derived from cladograms (both phylogenetic trees and network diagrams.  Some of these sub-groups were assigned a local geographic origin, and some an approximate age.  However SNP tests are now showing that while STR signatures are reliable for identifying distinguishing between branches they are not a reliable tool for dividing these branches into sub-groups, and so SNPs now form the basis of our second, current sub-division.  

27. Discovered in 2011 thanks to the initiative of one of our members in taking a "Walk-the-Y" test (now redundant), the R-L555 SNP is almost unique to our Borders branch.

28. FTDNA introduced their BigY Next Generation Sequencing test in 2013.  Although interpretation of the SNPs identified by early BigY test results initially proved difficult, a methodology was developed independently that gave interpretations of BigY data that was compatible with the work of leading L21 "citizen scientists" including Dennis Wright, Mike Walsh and Alex Williamson.  Today FTDNA place all newly identified SNPs on their publicly-recognised halpotree of mankind. 

29. Building on the results of our early BigY tests, including six funded in part by a few generous members, FTDNA launched their custom-designed L555 SNP Pack test in April 2016.  This tests for 86 SNPs within or downstream of the L555 block, and enables members of our large Borders branch who had not taken a BigY test to be placed on the FTDNA haplotree.  

30. The L555 section of FTDNA's haplotree has now been expanded to create a Border Irwin genetic family tree which as of end April 2024 includes 111BigY testers and many further testers whose have taken single SNP or Pack tests, have significant STR matches, or who are genealogically related to such testers.  This haplotree now includes 60% of Border Irwin testers.  

31. Analyses of these L555 BigY tests, including FTDNA's new "Discover" and "Time Tree" tools, suggests that the Border surname probably dates from the first half of the 14th century, as roughly predicted by contemporary records.  Most of Time Tree's mean TMRCA dates seem remarkably prescient. 

32. More specifically, these tests have enabled distinctive SNPs to be associated with the Bonshaw and Castle Irvine lines, and this triangulation means that the haplotree of mankind can now be extended down to within pedigrees developed by conventional genealogy - perhaps the "holy grail" of genetic genealogy.  The Study is one of a few that to date have been able to do this.

33. Several of our smaller branches now have at least 2 BigY tests, enabling simple branch- specific haplotrees to be constricted. 

34. As Administrator of this Study I have been privileged to lecture at a number of genetic genealogy conferences/events in England, Scotland, Ireland, USA and Australia.  These occasions have helped to publicise our Study, and at the same time establish a network that enables the Study to be kept abreast of emerging developments in other surname projects and genetic genealogy activities .  

35. I have also consolidated several decades of research into our surname into three recently published books which complement this Study and add historical background, particularly to the Irvines of Drum and the Border Irwins.  In particular the comprehensive The Irwin Surname: its Origins, Diaspora and Early Branches, published in 2020, has placed the Study in its wider genealogical context.  

36. While much has already been revealed about the origins of our surname and its branches and their sub-groups, including some surprises, it is clear that considerable further understanding will result from the efforts of individual Study members to improve their paternal pedigrees and from the rapidly evolving subject of genetic genealogy, and in particular from further Border Irwins taking the BigY test, now considerably cheaper than when it was launched.

37. The Study respects shared heritage of our surname and the diverse interests of our Study members, of the various branches of our surname, and of the Clan Irwin Association.  It welcomes all DNA testers around the world who share our surname, however they may spell it, whatever their origin, and immaterial of the length of their paternal pedigree, and testers who share our DNA but not our surname.  Through generous contributions of some existing members to the Study's General Fund, financial assistance can be offered to prospective members with long paternal pedigrees to join our Study.

38. The Study's Privacy Statement and other administrative arrangements are intended to comply fully with the European Union's new General Data Protection Regulation, ISOGG's Interim Guidance on GDPR, and FTDNA's Terms and Conditions.   The GDPR regime has not resulted in the loss of any members from our Study, and 95% of our members have opted to share their results in public. 

39. The on-going success of this Study is attributable to the technical and financial support given by several of its dedicated members, to the support (non-financial) and publicity given by the Clan Irwin Association, by several members of the International Society of Genetic Genealogists, and by FTDNA staff,  to the regular publication of detailed analyses of test results, and to our good fortune of inheriting a surname with such interesting genealogical and genetic features. 

James Irvine, Study Administrator, May 2024