Wednesday, August 4, 2010: 10:10 AM
306-307, David L Lawrence Convention Center
Background/Question/Methods
Speciation is often modeled and envisioned as an evolutionary process distinct from the ecological interactions within communities. Furthermore, ecological models of biodiversity, community organization and species coexistence often ignore the evolutionary processes that produced the species and shaped their characteristics. Yet, speciation occurs within an ecological context, and coexisting species within a community have been shaped by natural selection. Can game theory provide a conceptual unity that integrates speciation, adaptation, and the organization of species within communities? Advances in evolutionary game theory now include adaptive dynamics, evolutionary branching, niche coevolution, and the concept of evolutionarily stable minima. Here, I shall consider several models of species interactions. These models shall be formulated as evolutionary games using the concept of the fitness generating function. A fitness generating function (G-function) considers a group of species and/or populations that share the same set of evolutionarily feasible strategies, and the same fitness consequences of possessing a particular strategy. A community may contain species that come from one or several such G-functions. For instance, I shall use one or more G-functions to model a community of competitors, and use separate G-functions for their predators. A G-function might be thought of as containing members of the same Family or Order depending on the question of interest.
Results/Conclusions
Most of these models possess one or more ESSs (evolutionarily stable strategies), and these ESSs may possess one or more coexisting species from each of the constituent G-functions. Adaptive speciation from evolutionarily stable minima (evolutionary branching) and allopatric speciation (a means for bridging valleys of the adaptive landscape) permit low diversity systems to diversify and coevolve towards an ESS community. The addition of a predator G-functions tends to enhance the biodiversity at the ESS of prey G-functions. G-functions that represent primarily competitors tend to reduce the biodiversity within each even as overall biodiversity tends to increase with additional G-functions. Once established from speciation and adaptation, these ESS communities exhibit familiar patterns of community organization, mechanisms of coexistence, and species abundance patterns. Yet, an understanding of these communities requires knowledge of the underlying G-functions and evolutionary contexts. Important empirical questions emerging from these analyses include: 1) Are most communities most of the time at an ESS? and 2) Is speciation, as an ecological as well as evolutionary process, the means for filling out the species of an ESS?
Speciation is often modeled and envisioned as an evolutionary process distinct from the ecological interactions within communities. Furthermore, ecological models of biodiversity, community organization and species coexistence often ignore the evolutionary processes that produced the species and shaped their characteristics. Yet, speciation occurs within an ecological context, and coexisting species within a community have been shaped by natural selection. Can game theory provide a conceptual unity that integrates speciation, adaptation, and the organization of species within communities? Advances in evolutionary game theory now include adaptive dynamics, evolutionary branching, niche coevolution, and the concept of evolutionarily stable minima. Here, I shall consider several models of species interactions. These models shall be formulated as evolutionary games using the concept of the fitness generating function. A fitness generating function (G-function) considers a group of species and/or populations that share the same set of evolutionarily feasible strategies, and the same fitness consequences of possessing a particular strategy. A community may contain species that come from one or several such G-functions. For instance, I shall use one or more G-functions to model a community of competitors, and use separate G-functions for their predators. A G-function might be thought of as containing members of the same Family or Order depending on the question of interest.
Results/Conclusions
Most of these models possess one or more ESSs (evolutionarily stable strategies), and these ESSs may possess one or more coexisting species from each of the constituent G-functions. Adaptive speciation from evolutionarily stable minima (evolutionary branching) and allopatric speciation (a means for bridging valleys of the adaptive landscape) permit low diversity systems to diversify and coevolve towards an ESS community. The addition of a predator G-functions tends to enhance the biodiversity at the ESS of prey G-functions. G-functions that represent primarily competitors tend to reduce the biodiversity within each even as overall biodiversity tends to increase with additional G-functions. Once established from speciation and adaptation, these ESS communities exhibit familiar patterns of community organization, mechanisms of coexistence, and species abundance patterns. Yet, an understanding of these communities requires knowledge of the underlying G-functions and evolutionary contexts. Important empirical questions emerging from these analyses include: 1) Are most communities most of the time at an ESS? and 2) Is speciation, as an ecological as well as evolutionary process, the means for filling out the species of an ESS?
