Fig. 6: Comparison between two single simulations illustrating a biogeochemical-cycle “lock-in” trajectory.
From: The evolution of biogeochemical recycling by persistence-based selection
The two columns show two single model simulations under the same parameter choices, which differ from each other only in terms of the model’s stochastic processes. Both runs show a 2000 generation simulation, 600 generations into which sustained on-off fluctuations are induced in the influxes of both environmental substances. The start of each “off” interval involves an extreme population bottleneck during which only one randomly selected individual survives. Halfway through each simulation, mutation is switched off in all genotypes, mimicking genetic entrenchment. The left column shows a cycle “lock-in” event, the right a (more typical) population crash. Panels A, B show genotype frequencies, C, D fluxes, E, F cycling ratios, and G, H net quantity of environmental substances. Mutation rate \({\mu }_{0}=0.01\), producer cost \({\kappa }_{{prod}}=0.01\), shut-off interval during fluctuations 100 generations.
