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Fluctuating selection and the determinants of genetic variation
Olivia L Johnson1, Raymond Tobler2, Joshua M Schmidt3
1Australian Centre for Ancient DNA, School of Biological Sciences, University of Adelaide, Adelaide, Australia.
Trends in Genetics : TIG
|March 8, 2023
Summary
Seasonal changes in gene frequencies in fruit flies reveal widespread fluctuating selection. This review explores how these genetic shifts maintain variation in natural populations and impact genome-wide diversity.
Area of Science:
- Evolutionary biology
- Population genetics
Background:
- Cosmopolitan Drosophila populations exhibit thousands of genetic loci with seasonally fluctuating allele frequencies.
- This phenomenon places temporally fluctuating selection at the center of discussions on maintaining genetic variation in natural populations.
Purpose of the Study:
- To review recent evidence for multilocus fluctuating selection in Drosophila and other taxa.
- To highlight genetic and ecological mechanisms driving fluctuating selection.
- To assess the impact of fluctuating selection on neutral genetic variation.
Main Methods:
- Review of recent theoretical and experimental studies.
- Evaluation of empirical findings from Drosophila and other species.
- Analysis of genetic and ecological factors influencing allele frequency dynamics.
Main Results:
- Widespread evidence supports multilocus fluctuating selection in natural populations.
- Seasonal fluctuations in allele frequencies are common in Drosophila.
- Various mechanisms contribute to the maintenance of genetic variation under fluctuating selection.
Conclusions:
- Fluctuating selection is a significant force shaping genetic variation in natural populations.
- Understanding these dynamics is crucial for evolutionary biology.
- Further research is needed to fully elucidate the genome-wide impacts.
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