title: Thermodynamic behavior of a phase transition in a model for sympatric speciation.
abstract: We investigate the macroscopic effects of the ingredients that drive the origin of species through sympatric speciation. In our model, sympatric speciation is obtained as we tune up the strength of competition between individuals with different phenotypes. As a function of this control parameter, we can characterize, through the behavior of a macroscopic order parameter, a phase transition from a nonspeciation to a speciation state of the system. The behavior of the first derivative of the order parameter with respect to the control parameter is consistent with a phase transition and exhibits a sharp peak at the transition point. For different resources distribution, the transition point is shifted, an effect similar to pressure in a PVT system. The inverse of the parameter related to a sexual selection strength behaves like an external field in the system and, as thus, is also a control parameter. The macroscopic effects of the biological parameters used in our model are a reminiscent of the behavior of thermodynamic quantities in a phase transition of an equilibrium physical system.
authors.affiliation: Instituto de Física, Universidade Federal Fluminense, Campus da Praia Vermelha, Boa Viagem, Niterói, 24210-340, RJ, Brazil. karenluz@if.uff.br
authors.forename: K
authors.initials: K
authors.lastname: Luz-Burgoa
authors.forename: S
authors.initials: S
authors.lastname: Moss de Oliveira
authors.forename: Veit
authors.initials: V
authors.lastname: Schwämmle
authors.forename: J S
authors.initials: JS
authors.lastname: Sá Martins
mesh_terms: D005075:Biological Evolution; D003163:Competitive Behavior / Q000502:physiology*; D003198:Computer Simulation; D017753:Ecosystem; D049810:Genetic Speciation; D014644:Genetic Variation / Q000502:physiology; D005828:Genetics, Population; D008957:Models, Genetic; D011157:Population Dynamics; D013045:Species Specificity; D013816:Thermodynamics