Phenotypic-plasticity increases persistence in an individual-based model in which artificial evolution determines organism behavior.
PEACOR, SCOTT*,1, 2, RIOLO, RICK3, PASCUAL, MERCEDES3, 1 Michigan State University, East Lansing, email@example.com Great Lakes Environmental Research Laboratory, Ann Arbor3 University of Michigan, Ann Arbor
ABSTRACT- Many species respond to changes in the density of a second species by modifying phenotypically plastic traits. Such trait modifications can affect the interaction strength between the responding species and many other species in the system, and therefore pair-wise species interaction magnitudes are potentially a function of the density of multiple species. We use an individual-based model to examine how such phenotypic responses to changes in predator and resource densities affect the persistence of multiple competing consumers. In the model, each individual consumer has a set of parameters that controls its behavior. Populations of consumers are created by artificial evolution, in which each individual's parameters determine its ability to survive and reproduce, and offspring receive parameters from parents with the possibility of slight alterations (i.e. mutations). Species persistence was much greater in systems in which consumers could perceive and respond differentially to changes in predator density, i.e. exhibited phenotypic plasticity, than in systems in which they could not. This pattern is due, in part, to an increase in differential habitat usage in systems with phenotypic plasticity. We compare our results to those of other modeling approaches and discuss other areas of applicability of our framework.
Key words: individual-based model, persistence, phenotypic plasticity, genetic algorithm
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