Little Scottish Cluster

R1b - CTS2187 / S190
  • 463 members

About us

Since the founding of the project, administrators have worked to keep up with the latest tools to make meaning of project members' DNA test results. As the project grows and more members complete testing, the picture of the LSC becomes clearer. Below is a summary of the findings:

Insights from SNP Testing
As a result of widespread investment in advanced Big Y-700 by LSC project members and their test kit sponsors, there is now an emerging picture of how the various branches of the Little Scottish Cluster are related to one another that was not possible even a few years ago. As new Big Y recults come in from new or upgraded tests, the LSC section of the Tree of Mankind is further refined, with new test results taking place among their distant cousins.

Pre-LSC Ancestors
There are several SNPs of relevance to all Little Scottish Cluster members because they are "upstream" (earlier) mutations that led, eventually, to the first ancestor with the R-S190 mutation. With this, the path of mutations shared by all members of the LSC was locked in place, and the pre-Little Scottish Cluster ancestral line was defined.

These mutations, in order from oldest to youngest, are described briefly below: R-M343, R-L21, R-DF21, R-S424. See FTDNA's Discover - Suggested Projects page for further details about these projects.

R-M343
All LSC men also test positive for R-M343, a mutation that occurred approximately 22,000 years ago. R-M343 sits atop the most frequently occurring paternal lineage among Western European men and is also known as R-R1b. All R-M343+ men share a common ancestor approximately 19,000 years ago.

R-L21
The line of descent from R-M343 included many branches of descendants, including the major branch that led to the LSC: R-L21. This mutation is most closely associated with men with ancestry from the British Isles and is believed to have occurred approximately 4800 years ago.

R-DF21
Within a few hundred years after the arrival of first man to carry the R-L21 mutation, several branches had formed. The Little Scottish Cluster emerged from one such branch, called R-DF21. An analysis of men with this mutation further solidifies the British Isles presence of the LSC, as men with ties to Ireland, Scotland, England, and Wales make up much of the group. R-DF21 is estimated to have occurred approximately 4500 years ago, with a common ancestor to all R-DF21+ men having been born approximately 4350 years ago.

R-S424
Prior to Summer 2023, the Little Scottish Cluster project was tied to the R-S424 mutation, and the title of the project included that mutation. As more men completed advanced Y-DNA testing, it became clear that the R-S424 mutation occurred approximately 4100 years ago, long before the timeframe originally suggested by earlier testing. All LSC members test positive for R-S424, which occurred hundreds of years before the LSC-defining R-CTS2187 / R-S190 mutation. The former R-S424 is now known by its updated name, reflecting changes in our understanding of the timing of these mutations.

Insights From STR Testing
Prior to the arrival of Big Y testing in 2013, project founders and administrators used STR testing (Y-37, for example) to identify the LSC ancestral haplotype. At the time, this was the best available evidence for identifying group members. Although SNP testing for the presence of R-S190 is now the gold standard, men who have note taken SNP testing can still have their STR tests (Y-67, Y-111) compared with the original STR-based haplotype. 

 In the absence of SNP testing, administrators use the following guidelines to assess project eligibility based on STR testing:

The most distinguishing DYS marker, overall, is DYS590, for which all LSC men have the value 9, rather than the more common value 8. This marker is found only in the Y-67 and Y-111 marker test panels, so a minimum of 67 markers is required.

Prospective LSC members must match most of the other modal parameters, including the following: DYS464a=13 (some exceptions permitted) and DYS590=9 (if tested, no exceptions). They should also have most of the following values: DYS391=10, DYS458=18, DYS449=30, GATAH4=10, DYS413=22 or 23.

Project administrators can approve men tested with fewer than 67 markers if it appears the candidate matches a project member and is likely to upgrade his test to meet modal parameters in a reasonable timeframe. The vast majority of project members will test positive for R-CTS2187 / R-S190 when meeting the above modal parameters. There are a few rare exceptions to these, referred to and considered LSC Cousins.

Credits to Early LSC Researchers


Alex Williamson, a founding administrator and member of the Little Scottish Cluster was the person who identified and named the LSC. Alex is an acclaimed expert in the field of genetic genealogy, having developed and shared tools that helped other citizen scientists to extract meaning and value from their investment in genetic testing. In the mid-2000s, Alex created a website that tracked the emerging understanding of the LSC as new tools and additional data were emerging at the time. While the website is no longer being updated, it provides a glimpse into the process by which the LSC and its subgroups were discovered and definied. Those interested in learning more about the early days of LSC research will find value in seeing this pioneering work. Note that the website is not being actively maintained at this point and that many of the details have changed as a result of new evidence. See www.littlescottishcluster.com for a look at an archive of our earlier understanding of the LSC and its connection with other groups.

Kirsten Saxe and Steve Colson posted and maintained three modal haplotypes at Ysearch, a website that allowed researchers to gather and compare haplotypes of men tested at different companies. The website closed in 2018, but Kirsten and Steve's work was instrumental for those early LSC research collaborators.