Fig. S3.

Segregation rate affects qualitative model outcomes only at very high values. (A) To examine the sensitivity of the models to variation in plasmid segregation rate, we allowed segregation rates to vary between the species (${\delta }_1$ for species 1, ${\delta }_2$ for species 2), and the three models were run with 1,000 different combinations of different segregation rates for each species (from 10⁻⁶ to 10^−0.5). Each panel shows $P_1/\left(P_1+F_1\right)$ at the end of 5,000 iterations of the model plotted against the values of each parameter. Note that $P_1/\left(P_1+F_1\right)$ is strongly dependent on ${\delta }_1$, both with and without interspecific conjugation, but that this parameter does not affect plasmid survival unless it exceeds ∼10⁻² h⁻¹. (B) As in A, except the parameters are plotted against $P_2/\left(P_2+F_2\right)$. Note the different scales between A and B y axes. As with Fig. S1, the plasmid goes extinct in species 2 without interspecific conjugation. With interspecific conjugation both ${\delta }_1$ and ${\delta }_2$ affect $P_2/\left(P_2+F_2\right)$. However, the plasmid survives in species 2 even with high ${\delta }_2$, provided ${\delta }_1$ is sufficiently low to allow plasmid survival in species 1.