Figure 2.

The partial cooperators and cheaters generate diverse ecological dynamics

(A) The partial cooperators can oscillate with the cheater. In the chemical space, the intersection between the growth contours of a partial cooperator (blue) and a pure cheater (red) is represented by a black circle. The dynamical trajectory is represented by the small black dot with a black line. The background color indicates the growth-advantageous zone of partial cooperators over cheaters. The insert depicts the two species' competition dynamics.

(B) The partial cooperators can exclude the cheater. Same as (A), but the partial cooperators allocate more resources to private siderophores.

(C) The phase diagram illustrates the mechanism of oscillation shown in (A). In the left panel, the chemical space is divided into four regions with varying relative finesses (growth rate relative to dilution rate) between the cheater and the partial cooperators, denoted by the symbols + and -. The background color of the right panel corresponds to the regions in the chemical space depicted in the upper panel.

(D and E) Bifurcation diagrams for the system in (A) as the dilution rate (D) and the Fe³⁺ supply changes (E). Empty circles represent the minimum and maximum of the oscillation, while solid dots represent a steady state.