Underappreciated Consequences of Phenotypic Plasticity for Ecological Speciation

Figure 4

Effects of phenotypic plasticity of flowering time on ecological speciation. The lines illustrate flowering periods for plants on two soil types (dashed and solid) based on initial conditions in the simulations of Gavrilets and Vose [59] for ecological speciation based on the Howea palm tree study [60]. I illustrate the case where flowering time is affected by 8 loci, and the environmental effect of soil type is either 0, 2, or 4 weeks difference. In the simulations [59], changing the number of loci has confounding effects on the initial environmental variance component and the fitness effects of mutations, so a single genetic scenario is illustrated here for simplicity. I calculated the initial rate of gene flow between soil types as 𝑚= 0.5 (% time overlap), based on the assumption that any tree is equally likely to receive pollen from any other currently flowering tree. %speciation is based on the number of simulations ending in speciation, given in Table 2 of Gavrilets and Vose [59].