Mitochondrial DNA implies that almost all modern day dogs tumble into 1 of 4 monophyletic haplogroups that happen to be named haplogroups A, B, C, and D. Virtually all dogs fall inside haplogroup A. The mDNA "molecular clock" indicates that 22,800 YBP the first genetic divergence (break up) happened in haplogroup A, leading to the lineages A1b and