Genetic changes in slowly versus rapidly speciating lineages

If speciation is always accompanied by a discrete amount of genetic change, then the average genetic difference between species in speciose lineages (many species) ought to be greater than in species-depauperate lineages. For instance, the blue lineage has undergone two speciation events (horizontal branchings) in the same time that the red lineages has undergone eight. If the amount of genetic change associated with each speciation is the same (width of small black bar), the average genetic distance between red species will be approximately four-fold greater than that between blue species.