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DY: Fachverband Dynamik und Statistische Physik

DY 56: Poster - Statistical Physics

DY 56.15: Poster

Donnerstag, 19. März 2015, 16:00–18:00, Poster A

A minimalistic but realistic evolutionary food web model — •Tobias Rogge, Barbara Drossel, and Korinna T. Allhoff — TU Darmstadt, Germany

We present an evolutionary food web model that includes no population dynamics but is nevertheless able to generate a large variety of complex, multi-trophic networks with an ongoing turnover of species. The nodes represent species, which are characterized by three traits, namely body mass, feeding center and feeding range. These traits also define the links to other species in the network representing feeding and competition interactions.

The evolutionary algorithm starts with a simple initial network. At each iteration step, a new species is added to the system as a modification of a randomly chosen parent species. This "mutant" changes the environment for those species that now have a new predator, prey or competitor species. Some species are therefore removed from the system, if they no longer fulfill a survival criterion that depends on the interactions of the species. Subsequently, the next "mutant" is introduced. In contrast to many other evolutionary food web models, population dynamics is not explicitely taken into account. However, its effects are captured in the survival criterion. Thus, realistic network structures emerge and evolve with little computational effort. The model is therefore a valuable tool to evaluate statistical properties over long timescales, over a large parameter space, and for larger communities of coupled networks. We present selected results obtained from our simulations of the model.