title: Emergence of structured communities through evolutionary dynamics.
abstract: Species-rich communities, in which many competing species coexist in a single trophic level, are quite frequent in nature, but pose a formidable theoretical challenge. In particular, it is known that complex competitive systems become unstable and unfeasible when the number of species is large. Recently, many studies have attributed the stability of natural communities to the structure of the interspecific interaction network, yet the nature of such structures and the underlying mechanisms responsible for them remain open questions. Here we introduce an evolutionary model, based on the generic Lotka-Volterra competitive framework, from which a stable, structured, diverse community emerges spontaneously. The modular structure of the competition matrix reflects the phylogeny of the community, in agreement with the hierarchial taxonomic classification. Closely related species tend to have stronger niche overlap and weaker fitness differences, as opposed to pairs of species from different modules. The competitive-relatedness hypothesis and the idea of emergent neutrality are discussed in the context of this evolutionary model.
authors.affiliation: Porter School of Environmental Studies, Tel Aviv University, Ramat Aviv IL6997801, Israel. Electronic address: shtiler@gmail.com.
authors.forename: Elad
authors.initials: E
authors.lastname: Shtilerman
authors.affiliation: Department of Physics, Bar-Ilan University, Ramat-Gan IL5290002, Israel. Electronic address: kessler@dave.ph.biu.ac.il.
authors.forename: David A
authors.initials: DA
authors.lastname: Kessler
authors.affiliation: Department of Physics, Bar-Ilan University, Ramat-Gan IL5290002, Israel. Electronic address: nadav.shnerb@gmail.com.
authors.forename: Nadav M
authors.initials: NM
authors.lastname: Shnerb
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003163:Competitive Behavior; D017753:Ecosystem; D049810:Genetic Speciation; D008954:Models, Biological; D011157:Population Dynamics; D013045:Species Specificity
keywords: Competition; Generalized Lotka–Volterra dynamics; Modularity; Speciation; Species coexistence