title: Shape of ecological networks.
abstract: We study the statistics of ecosystems with a variable number of coevolving species. The species interact in two ways: by prey-predator relationships and by direct competition with similar kinds. The interaction coefficients change slowly through successful adaptations and speciations. They are treated as quenched random variables. These interactions determine long-term topological features of the species network, which are found to agree with those of biological systems.
authors.affiliation: Institut für theoretische Physik, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Lässig
authors.forename: U
authors.initials: U
authors.lastname: Bastolla
authors.forename: S C
authors.initials: SC
authors.lastname: Manrubia
authors.forename: A
authors.initials: A
authors.lastname: Valleriani
mesh_terms: D000818:Animals; D018533:Biomass; D017753:Ecosystem; D020387:Food Chain; D008954:Models, Biological; D011157:Population Dynamics