Mitochondrial DNA implies that nearly all fashionable dogs slide into a single of 4 monophyletic haplogroups that happen to be named haplogroups A, B, C, and D. Nearly all dogs slide inside haplogroup A. The mDNA "molecular clock" implies that 22,800 YBP the primary genetic divergence (break up) occurred in haplogroup A, leading to the lineages A1b