Evolution as a result of resource flow in ecosystems.

Individuals gain energy due to the flow of primary resources (with a rate λ per lattice site) and resource production out of interactions, and dissipate energy due to their metabolic costs (with a rate η per individual). Individuals die if go out of energy and reproduce when their internal energy reaches a threshold d, and pass their strategy (color coded) to their offspring, subject to mutations. In the absence of mutations, the model reduces to a purely ecological model of resource flow and production, and in the presence of mutations, evolution results. The interaction between individuals can be of any forms, and is modeled here as a public goods game with enhancement factor r.