County Clare is the epicenter for the Dal Cais tribe (includes the many of the descendants King Brian Boru as well as his ancestors). The YDNA haplogroup R-L226 represents a large percentage of those lines who can trace their ancestry to County Clare and Tipperary (as well as other neighboring counties in Munster, Ireland). This haplogroup project is very fortunate:
1) Of the testers who can trace their ancestors to a county in Ireland, 80 % reside in Munster, Ireland, 10 % reside in other parts of Ireland (migration during the last few hundred years) and 10 % in other parts of Europe (mostly England where many Irish reside today).
2) This is haplogroup is the second largest Irish YDNA haplogroup and has 550 testers at 67 markers. This haplogroup is very prolific probably being associated with King Brian Boru and his ancestors.
3) The characteristics associated with the R-L226 are ideal for genealogical connections. First, it is a prolific group of individuals over the last 1,400 years. Its YSTR "signature" is very genetically isolated from all other testers, it has its own dedicated YSNP pack (only a handful of haplogroups this recent of a YSNP coverage like this), it is greatly supported by three very active admins and it is greatly supported by hundreds of enthusiastic testers.
4) With extensive NGS testing (over 80 now), extensive L226 SNP pack almost 80 now and significant testing at YSEQ, we can now chart 80 % of how 550 testers are related. We just discovered our 51st YSNP branch under L226 this week and are adding another YSNP branch every week or two.
O'Brien and Casey testers dominate but there are dozens of Dal Cais surnames including McMahon (four at 67 markers). There are no Considine testers known to date but a major percentage of early residents of County Clare are known to be R-L226.
I will sponsor a 37 marker test for any Casey male who can trace their line back to 1870 or earlier (by birth date). The only other requirement is that you would agree to additional testing that may be requested. To see the extensive numbers of Dal Cais testers, see my haplotree chart of R-L226:
http://www.rcasey.net/DNA/R_L226/Haplotrees/L226_Home.pdf
