Niche Specialization Influences Adaptive Phenotypic Plasticity in the Threespine Stickleback

Richard Svanbäck, Dolph Schluter
2012 American Naturalist  
Phenotypic plasticity may be favored in generalist populations if it increases niche width, even in temporally constant environments. Phenotypic plasticity can increase the frequency of extreme phenotypes in a population and thus allow it to make use of a wide resource spectrum. Here we test the prediction that generalist populations should be more plastic than specialists. In a commongarden experiment, we show that solitary, generalist populations of threespine sticklebacks inhabiting small
more » ... stal lakes of British Columbia have a higher degree of morphological plasticity than the more specialized sympatric limnetic and benthic species. The ancestral marine stickleback showed low levels of plasticity similar to those of sympatric sticklebacks, implying that the greater plasticity of the generalist population has evolved recently. Measurements of wild populations show that those with mean trait values intermediate between the benthic and limnetic values indeed have higher morphological variation. Our data indicate that plasticity can evolve rapidly after colonization of a new environment in response to changing niche use.
doi:10.1086/666000 pmid:22673650 fatcat:ldn6l6iuvfeddawsozbzekvdkm