The Double-Edged Sword Effect of Assortative Mating on Adaptation

Area of Science:

• Ecology
• Evolutionary Biology
• Behavioral Ecology

Background:

• Evolutionary rescue is crucial for species persistence amid environmental change, integrating genetic and ecological factors.
• Assortative mating behavior, common in animals, has not been fully investigated for its role in evolutionary rescue.

Purpose of the Study:

• To explore the impact of assortative mating behavior on evolutionary rescue dynamics.
• To compare the effects of assortative mating versus random mating on population adaptation and persistence.

Main Methods:

• A simulation model was developed to study populations with assortative and random mating behaviors.
• The model simulated adaptation to new environments and tracked population dynamics.

Main Results:

• Assortative mating initially reduces phenotypic variance and slows beneficial mutation accumulation during population decline, increasing extinction risk.
• Conversely, assortative mating accelerates beneficial mutation accumulation in small populations, enhancing recovery rates, especially in later stages.
• Stronger assortative mating intensifies both extinction risk and population recovery rates.

Conclusions:

• Animal behavior, specifically assortative mating, significantly influences evolutionary rescue outcomes.
• Assortative mating presents a double-edged effect, posing risks but also offering benefits for population persistence under environmental stress.