Is Evolution in Response to Extreme Events Good for Population Persistence?

Area of Science:

• Ecology
• Evolutionary Biology
• Climate Change Science

Background:

• Climate change is intensifying environmental perturbations like storms and droughts, acting as significant selective pressures.
• These extreme events, often brief pulse disturbances, pose unique evolutionary challenges.
• Phenotypic changes adaptive during an event may become maladaptive post-event, impacting population recovery.

Purpose of the Study:

• To investigate how heritability and phenotypic variance influence population size and extinction risk under short-term extreme environmental events.
• To model the interplay between evolutionary adaptation and demographic recovery following pulse disturbances.

Main Methods:

• Utilized individual-based models and analytic approximations.
• Integrated quantitative genetics and demographic principles.
• Simulated finite populations experiencing extreme environmental events of fixed duration.

Main Results:

• Increased heritability can elevate extinction risk for populations during short extreme events due to maladaptation after the event.
• Conversely, heritability generally promotes population persistence when extreme events are of longer duration.
• For severe events, phenotypic variance can buffer populations, outweighing the load it imposes.

Conclusions:

• The duration of extreme environmental events critically determines the effect of heritability on population persistence.
• Phenotypic variance plays a crucial buffering role, especially during severe climate-related disturbances.
• Understanding these evolutionary dynamics is vital for predicting species' responses to climate change.