Figure 1.

Dispersion relations. Here, we examine the effect of each of the five parameters a, b, γ, δ, m on the dispersion relation for the system of equations (2.10)–(2.13). For panels (a–e), unless otherwise stated in the figure legend, a = 0.01, b = 1, γ = 10, δ = 0.05, m = 0. In panel (f), we examine the possibility of pattern formation when b = 0. Here, a = 0.1, m = 0.1, γ = 100 and δ varies according to the figure legend. See the electronic supplementary material, appendix B for an explanation of this choice of parameter values.