Fig. 4.

Fitness of coevolved bacterial isolates relative to their common ancestor, REL606. Isolates that coevolved with λunt are in teal and λtrn in red. The bacteria are labeled as in Fig. 3 except with treatment omitted. The mean relative fitness is significantly different between treatments with λunt ($\overline{w}$ = 0.972) and λtrn ($\overline{w}$ = 0.596, independent two-sample Student’s t test, t = −8.19, P < <0.001). However, the relative fitness of isolates with partial and complete resistance to λtrn does not differ (P = 0.67). Strains are ordered by treatment (λunt and λtrn) and then by increasing resistance according to PC1 (Fig. 3).