Adaptive food web models

For almost a century, mathematical studies of ecosystem dynamics have been based on the Lotka-Volterra differential equation approach. This approach has been able to integrate different actors, such as resources, producers, predators, decomposers and dise ase vectors. The great success has, however, come by strong restrictions on individual variability in all biological aspects, such as genetics, age/stage, state, and behaviour. It is proposed to study ecosystem dynamics by a series of individual-based pop ulation models, where the internal structure of each population changes as result of differential reproductive success within the population. In result, the gene pool of each population will adapt both towards each other and towards the physical environme nt. Hence, the ecosystem interactions will contain both density-dependent ecological interactions (as in the classical Lotka-Volterra) and evolutionary adaptation of the populations. This latter is assumed very important in the microbial food web, where e volutionary forces are strong. We therefore take the marine microbial food web as our case study.