Hello Derek, you said .........."Common missing links are M160 and M37?"> Using this link in the "Kerchner's R1b and Subclades yDNA Haplogroup Project" 2006 YDNA Haplogroup Tree from ISOGG http://www.isogg.org/tree/ISOGG_HapgrpR.html - I see they are common "failed" ones.......as well as P66 and S21? re this table of diagnostic polymorphisms :- R1b1c M269, S3, S10, S13, S17 . . . . . R1b1c* - . . . . . R1b1c1 M37 . . . . . R1b1c2 M65 . . . . . R1b1c3 M126 . . . . . R1b1c4 M153 . . . . . R1b1c5 M160 . . . . . R1b1c6 SRY2627 (M167) . . . . . R1b1c7 M222 . . . . . R1b1c8 P66 . . . . . R1b1c9 S21 (added) . . . . . . R1b1c9* - . . . . . . R1b1c9a L1 (S26) (added) . . . . . . R1b1c9b S29 (added) . . . . . R1b1c10 S28 (added) Ian Macdonnell