Phenotypic-plasticity increases species coexistence by changing the steepness of an adaptive landscape.
Peacor, Scott*,1, 2, Pascual, Mercedes3, Riolo, Rick3, 1 Michigan State University, East Lansing, MI2 NOAA Great Lakes Environmental Research Lab., Ann Arbor, MI3 University of Michigan, Ann Arbor, MI
ABSTRACT- Many species respond to changes in the density of a second species by modifying phenotypic plastic traits, i.e. species adapt to short term changes in the abundance of other species. We use an individual-based model to examine how the persistence of competing consumers is affected by phenotypic plasticity to varying predator density. In the model species behavioral traits (strategies) evolve, which in turn dictate the magnitude of species interactions. We examine cases in which species can, and cannot, detect and respond to predator density, which allows us to compare systems in which phenotypic plasticity can, and cannot, evolve. We find that phenotypic plasticity has a strong stabilizing effect. This supports earlier studies that phenotypic plasticity can affect stability. However in this study a different mechanism is at play because predator density is decoupled from consumer density in the model and therefore stability does not depend on effects of plasticity on the oscillatory behavior of predator-prey dynamics. Rather, phenotypic plasticity leads to steeper adaptive landscapes that prevent species invasion into occupied habitats and thereby increases the segregation of species into different habitats. Our approach shows that the interaction of trait evolution and short term adaptation to a dynamic food web can facilitate species coexistence.
Key words: coexistence, trait-mediated, plasticity, adaptive landscape
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