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Disentangling interactions between adaptive divergence and gene flow when ecology drives diversification
Katja Räsänen1, Andrew P Hendry
1ETH-Zurich, Institute of Integrative Biology, EAWAG, Department of Aquatic Ecology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland. katja.rasanen@eawag.ch
Ecology Letters
|April 4, 2008
Summary
Gene flow (GF) can limit adaptive diversification (AD) when species adapt to different environments without geographic barriers. However, adaptive divergence can also restrict gene flow, a process known as ecological speciation.
Area of Science:
- Evolutionary Biology
- Ecology
- Genetics
Background:
- Adaptive diversification (AD) occurs when populations adapt to distinct ecological environments.
- Gene flow (GF) can impede AD in the absence of geographic isolation.
- Ecological speciation proposes that AD can, in turn, limit GF.
Purpose of the Study:
- To investigate the bi-directional causality between adaptive diversification and gene flow.
- To explore methods for inferring causation in the context of ecological speciation.
- To evaluate the current evidence for GF constraining AD and vice versa.
Main Methods:
- Correlative studies examining relationships between AD and GF metrics.
- Analysis of correlations between AD and dispersal potential.
- Examination of correlations between GF and environmental heterogeneity.
- Discussion of experimental manipulations of dispersal and environment.
Main Results:
- Correlative studies often infer a negative relationship between AD and GF.
- Strong evidence suggests GF constrains AD.
- Some studies provide evidence for AD constraining GF, supporting ecological speciation.
Conclusions:
- Inferences of causation require careful consideration of bi-directional effects.
- Integrating multiple ecological and evolutionary variables enhances causal inference.
- Experimental approaches are crucial for robustly determining causality in adaptive diversification.
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