Fig. 2

Explanation of the Fourier analysis procedure. a We run the evolved network for 1800 steps with several, fixed concentrations of the morphogen. For every gene, we take the Fourier transform of the temporal gene expression dynamics to find the gene’s oscillation frequency for that particular morphogen concentration. We plot the Fourier transform data of all concentrations together in one heat map, where the colour intensity represents the amplitude at every frequency for every concentration. See also c for a “real-life” example. b For the network run at the highest morphogen concentration (representing the growth zone), we also perform a sliding-window analysis: here, we take subsets of the time series generated as in a and apply the Fourier transform to every window to visualize the change in frequency and amplitude over time in the growth zone. The rest of the procedure is the same as in a. c Examples of frequency profiles from real simulations. The plots in the left column are generated as explained in a, and those on the right as in b