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Sex releases the speed limit on evolution
1Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, UK. n.colegrave@ed.ac.uk
Nature
|December 13, 2002
Summary
Sexual reproduction boosts adaptation in large populations by speeding up beneficial mutations, but offers little advantage in small populations. Clonal interference is a key factor in this evolutionary benefit.
Area of Science:
- Evolutionary biology
- Genetics
- Microbiology
Background:
- The evolutionary maintenance of sexual reproduction is a long-standing question.
- Sex may accelerate adaptation by improving the fixation of beneficial mutations.
Purpose of the Study:
- To investigate the role of sex in adaptation to changing environments.
- To determine how population size affects the benefits of sex.
Main Methods:
- Studied adaptation in the facultatively sexual alga Chlamydomonas reinhardtii.
- Compared the rate of adaptation in sexual versus asexual reproduction across different population sizes.
Main Results:
- Sex significantly increased the rate of adaptation in large populations.
- The benefits of sex were minimal in small populations.
- Results suggest clonal interference plays a crucial role.
Conclusions:
- Sex enhances adaptive potential, particularly in large populations.
- Population size is a critical factor modulating the evolutionary benefits of sex.
- Clonal interference is an important mechanism explaining sex's advantage in adaptation.
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