Metapopulation structure favors plasticity over local adaptation

Area of Science:

• Evolutionary biology
• Population genetics
• Ecology

Background:

• Phenotypic plasticity allows organisms to adjust their traits in response to environmental changes.
• Understanding the evolutionary maintenance of plasticity in heterogeneous environments is crucial.
• Previous models, like Moran (1992), explored plasticity but often in simpler settings.

Purpose of the Study:

• To model the evolutionary consequences of phenotypic plasticity in a two-site metapopulation.
• To investigate the conditions under which a plastic type is favored over local specialists.
• To assess the role of migration and plasticity costs/accuracy on evolutionary outcomes.

Main Methods:

• Developed a mathematical model simulating a metapopulation with two distinct environmental sites.
• Incorporated three types: specialists for each environment and a generalist plastic type.
• Analyzed the model across a broad range of parameters, including migration rates, plasticity costs, and accuracy.

Main Results:

• The plastic type is favored over local specialists across a wide parameter range when migration occurs between sites.
• Plasticity can dominate or become fixed even in a uniform environment if migration is present.
• Migration relaxes the requirements for environmental heterogeneity and plasticity accuracy for its advantage.

Conclusions:

• Migration rates are a significant, potentially underappreciated factor in adaptive population differentiation.
• Phenotypic plasticity can be evolutionarily stable and prevalent even with imperfect accuracy or fitness costs, given sufficient migration.
• Small changes in plasticity accuracy can lead to abrupt shifts in metapopulation evolutionary trajectories.