FIG. 20.

(Color online) Genetic drift during a linear range expansion in the undulating-front model with three alleles. (a) The genetic composition of the population [𝔣₁(t),𝔣₂(t),𝔣₃(t)] projected on the plane ${\mathrm{\Sigma }}_{i=1}^3{𝔣}_i(t)=1$ in a single run of the neutral three-allele model with an undulating front. The population is finite, L=1000, and there are no mutations. (b) The average standard deviation of the frequency of allele one Δ(t) is obtained from 200 realizations of the simulations described in (a). The solid line shows the best power-law fit and the slope is close to the exponent expected from Eq. (E8). The gray area encloses the points within one standard deviation from the mean. At t=0, each site is assigned either allele one or allele two with equal probability, which corresponds to the center of the triangle in (a).