Fig. 3.

Evolution of host resistance range (A), growth-resistance trade-off (B), and host diversity (C) in host–virus (gray/black) and complex system (orange). (A) Average host resistance range (from 10 clones per chemostat and time points) increased over time from susceptible (0 = nonresistant) to maximum (1 = general resistant host), but did not reach 1 as general resistant hosts coexisted together with less resistant host clones. Host resistance range increased significantly different between two systems. Orange boxes represent periods in which predator was present in the complex system. (B) Host per capita growth rate (±SEM) decreased with increasing host resistance range. The trade-off observed in the host–virus (gray) and complex system (orange) was not significantly different (only hosts from days 0–58 for the host–virus and complex system). (C) Average diversity of host resistance ranges over time. Dashed horizontal lines show averages for the period when general resistant host was first detected until day 57 and for the period after the predator was added to the complex system. Host diversity was high in both the host–virus and complex system period before the predator was added, but was significantly reduced after the predator was added to the complex system (n = 3). All error bars show SDs.