title: Case studies and mathematical models of ecological speciation. 1. Cichlids in a crater lake.
abstract: A recent study of a pair of sympatric species of cichlids in Lake Apoyo in Nicaragua is viewed as providing probably one of the most convincing examples of sympatric speciation to date. Here, we describe and study a stochastic, individual-based, explicit genetic model tailored for this cichlid system. Our results show that relatively rapid (<20,000 generations) colonization of a new ecological niche and (sympatric or parapatric) speciation via local adaptation and divergence in habitat and mating preferences are theoretically plausible if: (i) the number of loci underlying the traits controlling local adaptation, and habitat and mating preferences is small; (ii) the strength of selection for local adaptation is intermediate; (iii) the carrying capacity of the population is intermediate; and (iv) the effects of the loci influencing nonrandom mating are strong. We discuss patterns and timescales of ecological speciation identified by our model, and we highlight important parameters and features that need to be studied empirically to provide information that can be used to improve the biological realism and power of mathematical models of ecological speciation.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA. sergey@tiem.utk.edu
authors.forename: Sergey
authors.initials: S
authors.lastname: Gavrilets
authors.forename: Aaron
authors.initials: A
authors.lastname: Vose
authors.forename: Marta
authors.initials: M
authors.lastname: Barluenga
authors.forename: Walter
authors.initials: W
authors.lastname: Salzburger
authors.forename: Axel
authors.initials: A
authors.lastname: Meyer
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D023681:Cichlids / Q000145:classification* / Q000502:physiology; D017753:Ecosystem; D005618:Fresh Water; D008954:Models, Biological; D013045:Species Specificity; D013997:Time Factors