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Updated: Jun 4, 2026
15:00
Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli
Published on: August 18, 2023
Persistent trade-offs balance competition and colonization across centuries.
Talia Backman1, Jiajun Cui2, Emma Caullireau1
1School of Biological Sciences, University of Utah, Salt Lake City, UT 84112.
Summary
In natural Pseudomonas populations, a trade-off between microbial competition and host colonization has persisted for centuries. This fundamental balance between competitive killing and pathogenicity is not easily overcome by evolutionary adaptation.
Area of Science:
- Microbial Ecology
- Evolutionary Biology
- Genomics
Background:
- Microbial competition drives rapid adaptation and niche specialization.
- Adaptations enhancing competitive ability can create trade-offs, reducing performance in other environments.
- The persistence of such trade-offs in natural populations is largely unknown.
Purpose of the Study:
- To investigate the stability of trade-offs between competitive ability and host colonization in natural Pseudomonas populations.
- To determine if evolutionary adaptations erode or maintain these trade-offs over time.
Main Methods:
- Genomic surveys of wild plant-pathogenic Pseudomonas.
- Functional assays to assess tailocin production and its effects.
- Analysis of historical genomes spanning two centuries.
Main Results:
- A stable trade-off exists between Pseudomonas competitive ability and plant colonization.
- Broadly lethal tailocins, while increasing competitive killing, compromise host colonization.
- This trade-off has been maintained for at least 10^5 to 10^6 generations.
Conclusions:
- Trade-offs between competition and pathogenicity are fundamental in natural Pseudomonas populations.
- These trade-offs are stably maintained and not easily overcome by compensatory evolution.
- The findings highlight the enduring nature of ecological trade-offs in microbial evolution.
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