Fig. 5.
Bistability and robustness of adaptor bias (ratio of adaptor concentrations) for the two-letter model. The equilibrium adaptor bias, ψc, is plotted as a function of the number of mutations per genome per generation, μL, for different model parameters. All curves are for ϴ = 0. Thick blue line, exact solution of the symmetric case m = 0, α = 1, with the two letters being synonymous at all genome sites. Solid red line, same as the above except for the presence of strong mutational asymmetry, m = 0.9; the dotted red line indicates the unstable equilibria. Red balls, simulation of the previous case (m = 0.9), but 4.55% of the sites are fixed to letter 1, and 4.55% are fixed to letter 2. Green line, bias of the two solutions (Top and Bottom branches for the same μL) at the onset of bistability for different m >0 in the synonymous model.