His model– higher fitness = higher virulence. Can derive duration of infection, number of secondary infections, transmission rate, geometric mean fitness. No tradeoff between transmission and mortality. Fitness maximized at intermediate virulence.
Syringae is a diverse group of plant associate bateria. Frequently pathogen but commonly epiphtic and environmental. What about aphids? Two variants of syringae– one pathogenic and one not. Fall into different clades. Appear to just be two losses of virulence.
Not much of virulent strain needed to kill bug. Lots of avirulent strain can kill bug.