Figure 7.

The average time until fixation of an uninfected population that receives a constant (small) influx of Wolbachia at rate m. We assume that all individuals die at rate Φ, so that average lifespan is 1/Φ and the number of infected individuals in the naive population at any one time is on average m/Φ. Time is measured in units of average lifetime. (a) Average waiting time as a function of population size for Wolbachia with positive, neutral and negative effects on fitness (s_h=1, m/Φ=0.1) and (b) average waiting times as a function of introduction rates for the same values of Wolbachia fitness effects (s_h=1, N=250). Further details of calculations are given in the electronic supplementary material.