How does the mutation rate of speciation in the Dobzhansky- Muller model? How does the mutation rate affect the rate of speciation in the Dobzhansky Muller model? An increased mutation rate results in a more rapid reproductive isolation between the two diverging populations. O An increased mutation rate results in slower reproductive isolation between the two diverging populations. The mutation rate is unrelated to the rate of evolution of reproductive isolation. Solution ans- a increased mutation rate results in a more reproduction isolation between the two diverging population. an ancestral population splits into two parts the two lineage begins to diverge genetically which are temporally isolated from each other.new alleles evolved at one locus of lineage and different alleles evolved in another locus of the lineage..