Results
Group 1 members have similar STR results overall that suggest that they descend from a common ancestor. All Group 1 members have also taken a DYS464X test which showed that they have 2 c type and 2 g type alleles on the DYS464 markers. Because most men in Haplogroup R1b have 3 c type alleles and 1 g type allele on the DYS464 markers, the configuration with 2 c and 2 g type alleles helps confirm their descent from a common ancestor.
Group 2 members have STR results that are very similar to the results of Group 1 members, but they have taken a DYS464X test which showed that they have 4 c type alleles on the DYS464X markers. This is a very surprising result, because the known paths by which 4c and 2c2g lines might be created from a particular line and lead to very similar haplotypes are quite complicated, involving a number of unlikely mutation events. This process is likely to have taken a long time, which implies that the relationships between Group 2 and Group 1 members may be more distant than a comparison of their haplotypes excluding the DYS464X test results suggests. Group 2 members may share a common 4c ancestor, but it is also possible that their lines became 4c via independent mutations. Members of this group are eligible to join the 464xQuadC project at FTDNA, and are encouraged to do so, but we also encourage them to remain in this project as we explore the relatedness of the two groups.
Group 3 members have STR results very similar to the results of Group 1 members, but they have DYS464X test results with 3 c type alleles and 1 g type allele on the DYS464 markers. The similarity of their results to the results of Group 1 members may be due in part to coincidence, but it seems likely that they descend from a relatively close relative of the Group 1 founder. Another possibility would be descent from the Group 1 founder, followed by a mutation changing one g type allele to a c type allele. The STR results for the men assigned to Group 3 are not extremely similar, so it seems likely that their common ancestry does go back some time close to the founding of Group 1. So the possibility that they are cousins of the Group 1 members seems the most likely. The first 2 members added to this group share the somewhat unusual value of 14 on DYS393. Group 1 members with 37 marker results match typical cluster member results on each of the 5 key markers that are most helpful for differentiating cluster members from non-members. Group 1 members with 67 marker results match the typical results for cluster members on at least 6 of the most useful 7 key markers for distinguishing cluster members from non-members in the 67 marker set. The 7 signature marker values for the cluster are DYS389-1, 14 or higher; DYS448, 18 or lower; CDYa, 39, but 38 or higher is counted as a match; CDYb, 40, but 39 or higher is counted as a match; DYS442, 11 or lower; DYS557, 17 or higher; DYS446, 14 or higher.
Group 4 members are similar to Group 2 members. Both groups have results similar to the STR results for Group 1, but have 464X test results with 3 c type alleles and 1 g type allele. The results for Group 4 members are a little less similar to the results of Group 1 members, suggesting that they are more distantly related to Group 1.
Group 5 members also have STR results similar to the results of Group 1 members, but they are not 2c2g, and they are also not in the same R-L21 haplogroup. This means that their most recent common ancestor with members of the Leinster cluster and other members of R-L21 lived thousands of years ago.
Unclustered 2c2g members have taken the DYS464X test and do have 2 c type and 2 g type alleles, just as the men in Group 1 do, but their overall STR results do not show a lot of similarity to the results of men in Group 1. Most or all of these men probably inherited their 2c2g configuration from ancestors who were not ancestral to Group 1.
The Not 2c2g-3c1g group members have joined at various times for various reasons. Some joined because their results were similar to the results of other project members in Group 1, and others were asked to join to share their haplotypes with 3 c type alleles and 1 g type allele as revealed by the DYS464X test. Looking at at these "3c1g" haplotypes may be helpful when evaluating the probability that a man with STR results is a member of Group 1 or another "2c2g" cluster.