Mitochondrial DNA implies that nearly all contemporary dogs tumble into one of 4 monophyletic haplogroups that are named haplogroups A, B, C, and D. Many dogs tumble in just haplogroup A. The mDNA "molecular clock" implies that 22,800 YBP the primary genetic divergence (split) transpired in haplogroup A, resulting in the lineages A1b and A2. This t