Evidence from simulation studies for selective constraints on the codon usage of the Angiosperm psbA gene
Fig 1
Simulation results for the ML_AA ancestral sequence of psbA under 5 models; MC with synonymous substitutions only, MC with nonsynonymous substitutions, MC2020 with synonymous substitutions only, MC2020 with nonsynonymous substitutions, and K2P with synonymous substitutions only.
The four MC and MC2020 models are shown in black and the K2P model in red.