I-L161 "Isles" men fall into three categories: L161+ L1498- PF4135- L161+ L1498- PF4135+ L161+ L1498+ PF4135- Most people in L161+ are either L1498+ or PF4135+, very few people are negative for both SNPs. The people in Ken's Isles-C, Isles-D and most of his Isles-B groups are L1498+. The people in Ken's Isles-A1 and Isles-A2 groups are PF4135+. There are a few people in some of his Isles-B groups who are L1498- and PF4135-. A man named Dover kit 23143 did Geno 2.0 and received L161+ PF4135- results and a strong indication of L1498- results. I thought Dover belonged in Isles-A because he had the distinctive marker values that distinguish Isles-A from other kinds of Isles: DYS454=12, YCAII=19,21, DYS557=17, DYS444=12, also DYS447=24, DYS437=14. And he is a GD of 10 at 67 from some Isles-A people. But he has DYS511=12. Isles-A usually has 11 which is rare in other Isles people. Most Isles-B, C and D have 10. Still, he has a high value at 511 just like the Isles-A people. Dover received Geno 2.0 results of L161+ PF4135- and a strong indication of L1498-. This was a surprise. So I asked other men who were close to Isles-A but who didn't match all of the important marker values to test PF4135 and L1498 at FTDNA which has a more exact way of testing SNPs than the Geno 2.0 test. It turned out that all of these men were L1498+ and so they are probably some kind of Isles-B (these people are named Taylor, Hood, Winchester). So I thought it was important to confirm Dover's results for these two SNPs and I asked him to test them at FTDNA, and he has received L1498- and PF4135- results. I believe these FTDNA results, and I think it means that the PF4135 mutation happened relatively recently. I will try to look for other people who are close to the Isles-A modal but who lack some of the key marker values and ask them to test PF4135. Bernie