Figure 2. The eco-evolutionary setup of the model.

(a) A population of $N\mathrm{=}\mathrm{200}$ cells moves by chemotaxis towards the peak of the gradient, which in this season is located at the left boundary of the grid. (b) At the end of the season, cells divide, the population excess is killed randomly, and the direction of the chemotactic signal is changed, after which the new season begins (c, d). The snapshots are taken at the indicated time points from a simulation where a season lasts ${\tau }_s\mathrm{=}\mathrm{100}\mathrm{\times }{\mathrm{10}}^{\mathrm{3}}$ MCS. Dashed lines in the snapshots are gradient isoclines.