Evolution of species' range and niche in changing environments

Area of Science:

• Ecology
• Evolutionary Biology
• Conservation Biology

Background:

• Understanding species' niche and range shifts is crucial for assessing population resilience amid climate change.
• Current eco-evolutionary theories often neglect critical interactions between ecological and evolutionary forces, limiting predictive power.

Purpose of the Study:

• To provide quantitative, testable predictions on the limits to adaptation in changing environments.
• To explore the feedback between selection, genetic drift, and population dynamics.

Main Methods:

• Developed a theoretical framework to predict eco-evolutionary responses.
• Identified an "expansion threshold" determined by spatial/temporal variability and genetic drift.
• Analyzed the impact of population size and dispersal on genetic diversity and adaptive potential.

Main Results:

• Eco-evolutionary feedback can lead to a tipping point where adaptation fails, causing abrupt range contractions or fragmentation.
• Genetic drift, strong in small populations, depletes local genetic variance beyond the expansion threshold, increasing extinction risk.
• Increased dispersal, such as through assisted migration, can enlarge neighborhood size, counteracting drift and enhancing adaptive potential.

Conclusions:

• The study highlights the critical role of eco-evolutionary interactions in determining species' range dynamics.
• The proposed "expansion threshold" offers predictions beyond standard ecological niche models.
• Findings emphasize the importance of genetic diversity and dispersal for evolutionary rescue and species resilience in the face of environmental change.