Fig. 4
Bifurcation diagrams of both Beca (black lines) and Casp (gray lines). Codimension-one bifurcation curves with respect to a S1 at S2 = 0.2 and b S2 at S1 = 0.2. Stable steady states and unstable steady states are represented by solid and dotted lines, respectively. F is the equilibrium fold bifurcation point. c Codimension-two bifurcation diagram with respect to S1 and S2; the black line is the equilibrium fold bifurcation curve