Evolutionary Stability of Jointly Evolving Traits in Subdivided Populations

Area of Science:

• Evolutionary Biology
• Population Genetics
• Behavioral Ecology

Background:

• Understanding evolutionary stability in well-mixed populations is established.
• Subdivided populations and joint evolution of multiple traits present complexities in predicting evolutionary stability.
• Limited dispersal in subdivided populations can lead to kin selection and affect trait evolution.

Purpose of the Study:

• To investigate evolutionary stability in spatially subdivided populations with multiple jointly evolving traits.
• To determine conditions under which a population resists invasion versus undergoing diversifying selection.
• To explore trait correlations arising from diversifying selection and their dependence on relatedness.

Main Methods:

• Mathematical modeling of a spatially subdivided population.
• Analysis of evolutionary stability at a monomorphic equilibrium for multiple quantitative traits.
• Investigation of trait correlations under diversifying selection, focusing on dispersal and helping behaviors.

Main Results:

• Selection favors positive (negative) trait correlations when the effect of one trait on relatedness is positively (negatively) correlated with the indirect fitness effects of another trait.
• When dispersal costs are low and helping benefits increase rapidly, selection promotes coexistence of mobile defectors and sessile helpers.
• In other scenarios, populations evolve towards a monomorphic state with intermediate levels of helping and dispersal.

Conclusions:

• Population subdivision significantly impacts evolutionary stability and can drive trait correlations.
• The interplay between dispersal and cooperative behaviors (like helping) in structured populations can lead to diverse evolutionary outcomes.
• Understanding these dynamics is crucial for predicting the evolution of social traits and population structures.