GENETIC MODELS OF ADAPTATION AND GENE FLOW IN PERIPHERAL POPULATIONS

Area of Science:

• Evolutionary biology
• Population genetics
• Ecology

Background:

• Peripheral populations of widespread species face unique evolutionary pressures.
• Understanding gene flow's impact on local adaptation is crucial for evolutionary studies.

Purpose of the Study:

• To model the evolutionary dynamics of quantitative traits in peripheral populations.
• To investigate how gene flow from central populations affects adaptation at range edges.
• To explore the role of isolation in driving peripheral evolution.

Main Methods:

• Development of theoretical models for quantitative trait evolution.
• Analysis of clinally varying selection across a species' range.
• Simulation of gene flow and selection in peripheral populations.

Main Results:

• Gene flow from central populations can impede peripheral adaptation, leading to persistent directional selection.
• Isolation from gene flow allows peripheral populations to evolve rapidly in response to local selection.
• The extent of evolutionary change is influenced by gene flow, selection intensity, ecological gradients, and heritability.
• Vicariant events disrupting gene flow can promote rapid divergence.

Conclusions:

• Disruption of gene flow is a significant driver of evolutionary divergence in peripheral populations.
• Reduced gene flow can lead to substantial evolutionary change and potentially speciation, even without genetic drift.
• Peripheral populations are key to understanding the interplay between gene flow and adaptation.