Figure 3

Two evolvability benefits of coevolving phage. Bacterial evolution on different adaptive landscapes with/without coevolving phage. A: Standing diversity aids adaptation in dynamic environments (colours show landscape change over time). B: Local trade-offs allow adaptation across fitness valleys on landscapes with multiple peaks. Top: Growth rate function, plotting maximum growth rate (δγ) as a function of genotype. Middle: Density contours showing distribution of bacterial and phage genotypes over time, for bacteria evolving alone (yellow), and for bacteria (blue) coevolving with phage (red). Bottom: Fitness landscape for bacteria coevolving with phage, plotting density contour (black) over field for rate of density change $\left(\frac{\mathit{\text{dN}}}{\mathit{\text{dt}}}\right)$. Parameter settings as Table 1 except for M _V =10⁻⁵and V _init =0 for no-phage treatments.