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Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
Allele fixation in a dynamic metapopulation: founder effects vs refuge effects
Robin Aguilée1, David Claessen, Amaury Lambert
1Laboratory of Ecology and Evolution (UMR 7625, University Paris 06, Ecole Normale Supérieure, AgroParisTech, CNRS), Unit of Eco-Evolutionary Mathematics, F-75005 Paris, France. robin.aguilee@biologie.ens.fr
Theoretical Population Biology
|May 26, 2009
Summary
Dynamic landscapes, including bottlenecks and fragmentation, reduce advantageous mutant fixation probability by causing founder effects. These effects can also accelerate fixation, but refuge effects may delay it, depending on landscape dynamics.
Area of Science:
- Evolutionary genetics
- Population genetics
- Ecological dynamics
Background:
- Metapopulation models typically assume static spatial structures.
- Natural populations experience dynamic changes in size, fragmentation, and connectivity.
- These dynamic landscape changes influence evolutionary processes like mutant fixation.
Purpose of the Study:
- To investigate the impact of dynamic landscapes on mutant allele fixation probability and time.
- To analyze how repetitive population size variations and connectivity changes affect evolutionary trajectories.
- To quantify the influence of founder and refuge effects in dynamic metapopulations.
Main Methods:
- Derivation of variance, coalescent, and harmonic mean effective population sizes.
- Stochastic simulations of three dynamic landscape models: repetitive bottlenecks, fragmentation-fusion with constant carrying capacity, and fragmentation-fusion with variable carrying capacity.
- Analysis of mutant fixation probability and fixation time under different landscape dynamics.
Main Results:
- Dynamic landscapes generate repetitive founder effects that counteract selection, decreasing fixation probability for advantageous mutants.
- Founder effects accelerate fixation when it occurs, but can be counteracted by a refuge effect that delays fixation.
- The interplay between founder and refuge effects, and their impact on fixation, depends on the timescale of landscape dynamics.
Conclusions:
- Dynamic landscape structures significantly alter the evolutionary dynamics of mutant fixation compared to static models.
- Repetitive founder effects and refuge effects are key mechanisms by which landscape dynamics influence fixation probability and time.
- Understanding landscape dynamics is crucial for predicting evolutionary trajectories in natural populations.
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