Genetic drift and selection in many-allele range expansions
Fig 14
A schematic of the simulation procedure for a radial expansion.
The initial population is a circle of cells of radius R0 = N0a/2π, where N0 is the initial number of cells and a is a cell width. During each time step (generation), the expansion advances a distance a; the radius consequently grows according to R(t) = R0 + at where t is the time in generations. The dashed circle shows the population after one generation time. Each domain wall position is tracked on the inflating ring (solid lines). At each time step, domain walls (two shown) hop to the left or right with probability Pl and Pr, respectively, with an angular jump length δϕ ≡ a/R(t), and the position is updated (dashed lines). After each domain wall movement, the time in generations is incremented by 1/N where N is the number of domain walls present. For a linear simulation, the radius is simply not inflated in time, i.e. R(t) = R0.