Selection and the Rapidity of Evolution in Prokaryotes Wild-type cell Pigment mutants Light 15 -Dark Mutants lost in 10 light 部8 Mutant Cell populations selected in dark Pigment mutants 5 Wild 1 2 3 45 type P880 pooo 5 10 15 20 Subculture number 2012 Pearson Education.inc Chen Feng,Shanghai Jiao Tong UniversityChen Feng, Shanghai Jiao Tong University Selection and the Rapidity of Evolution in Prokaryotes