When do adaptive plasticity and genetic evolution prevent extinction of a density-regulated population?

Area of Science:

• Ecology
• Evolutionary Biology
• Population Dynamics

Background:

• Environmental shifts can cause population declines due to maladaptation.
• Phenotypic plasticity and genetic evolution are key mechanisms for population recovery.
• Density dependence influences population persistence and extinction risk.

Purpose of the Study:

• To investigate the dynamics of evolutionary recovery after environmental change.
• To assess the roles of phenotypic plasticity and genetic evolution in population persistence.
• To understand how density dependence affects recovery from environmental shifts.

Main Methods:

• Modeling density-regulated populations with evolving plasticity.
• Analyzing selection on a quantitative trait under density-independent conditions.
• Using theta-logistic population regulation to model density dependence.

Main Results:

• Partially adaptive plasticity initially reduces the impact of environmental change.
• Evolution of plasticity accelerates adaptation and enhances population persistence.
• Density dependence, particularly with lower theta values in theta-logistic models, hinders recovery and increases extinction risk.

Conclusions:

• Phenotypic plasticity and genetic evolution are crucial for populations to recover from abrupt environmental changes.
• While plasticity and evolution promote persistence, density dependence remains a significant challenge.
• The specific form of density dependence (theta-logistic) critically impacts extinction risk.