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Updated: Jul 10, 2026
08:57
Using Phylogenetic Analysis to Investigate Eukaryotic Gene Origin
Published on: August 14, 2018
The effect of selection on genealogies
1Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, UK. n.barton@ed.ac.uk
Genetics
|March 17, 2004
Summary
Weak selection
Area of Science:
- Population genetics
- Evolutionary biology
- Molecular evolution
Background:
- Coalescent theory models genetic drift
- Deterministic models of selection are limited to strong selection
- Understanding weak selection effects on genealogies is crucial
Purpose of the Study:
- Develop methods to quantify weak selection effects on genealogies
- Extend Price's equation to incorporate weak selection
- Analyze how selection impacts coalescence times
Main Methods:
- Extension of Kaplan, Darden, and Hudson's methods
- Application of an extended Price's equation
- Analysis of coalescence time distributions and moments
Main Results:
- Weak selection's effect is a covariance between gene properties and fitness
- Average coalescence time is largely insensitive to allele frequency
- Purifying selection significantly impacts coalescence only when Ns > 3
- Balancing selection's effect on coalescence requires low mutation rates and strong selection
Conclusions:
- Selection has a surprisingly small effect on genealogies
- Random drift can mask or reduce the detectable effects of selection
- Detecting selection from neutral variation alone is challenging
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