Figure 2.

Interaction plot of fitted rFS, showing how the protection levels depend on frequency and density. For this specific case (involving producers of β-lactamase harbouring the R1 plasmid at structured habitat), one can see that protection levels are higher at higher densities, but even higher if frequency is intermediate (50S:50R) or low (1S:99R). Error bars show twice the s.e. around the means.