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Published on: October 29, 2016
Population bottlenecks promote cooperation in bacterial biofilms
1School of Biological Sciences, University of Liverpool, Liverpool, United Kingdom. michael.brockhurst@liv.ac.uk
Plos One
|July 27, 2007
Summary
Microbial cooperation, like biofilm formation, is maintained by population bottlenecks. Smaller bottlenecks increase relatedness, favoring cooperation, while larger ones promote cheating in bacteria like Pseudomonas fluorescens.
Area of Science:
- Microbial Ecology
- Evolutionary Biology
- Behavioral Ecology
Background:
- Social traits in microbes are crucial for survival and adaptation.
- Ecological factors, such as population bottlenecks, are hypothesized to maintain microbial cooperation by increasing genetic relatedness.
Purpose of the Study:
- To experimentally investigate the role of population bottleneck size in the evolution of cooperation.
- To test the prediction that smaller bottlenecks favor cooperation by increasing relatedness.
Main Methods:
- Experimental evolution using the bacterium Pseudomonas fluorescens.
- Simulating population bottlenecks of varying sizes (10^3 to 10^8 cells) every four days.
- Quantifying the frequency of cooperative (biofilm formation) and non-cooperative (cheater) phenotypes.
Main Results:
- The frequency of evolved cheaters increased significantly with larger population bottleneck sizes.
- Conversely, smaller bottleneck sizes were associated with a higher prevalence of cooperation.
Conclusions:
- Population bottleneck size is a critical factor in the maintenance of microbial social traits.
- Ecologically mediated population structures, specifically smaller bottlenecks, can prevent the proliferation of non-cooperative behaviors.
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