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Updated: Jul 4, 2025
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Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli
Published on: August 18, 2023
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Competition-driven eco-evolutionary feedback reshapes bacteriophage lambda's fitness landscape and enables speciation
Michael B Doud1,2, Animesh Gupta2, Victor Li2
1Department of Medicine, Division of Infectious Diseases and Global Public Health, University of California San Diego, San Diego, CA, USA.
Nature Communications
|January 29, 2024
Summary
Populations adapt by reshaping their fitness landscapes, which can prevent getting stuck on suboptimal peaks. This dynamic landscape evolution drives speciation and diversification, as shown in bacteriophage evolution experiments.
Area of Science:
- Evolutionary Biology
- Speciation
- Virology
Background:
- Populations face challenges navigating complex fitness landscapes and avoiding local optima.
- Adaptive dynamics theory suggests adaptation restructures landscapes, potentially promoting speciation.
- Empirical evidence directly measuring landscape deformation during adaptation and its link to diversification is lacking.
Purpose of the Study:
- To empirically measure fitness landscape deformation during adaptation.
- To test if landscape shifts promote diversification and speciation.
- To investigate the role of bacteriophage [Formula: see text] evolution in this process.
Main Methods:
- Utilized high-throughput gene editing and phenotyping to map bacteriophage [Formula: see text] fitness landscapes.
- Assessed fitness in the presence of different evolved competitors.
- Simulated bacteriophage [Formula: see text] evolution on static versus dynamically deforming landscapes.
Main Results:
- Fitness effects of mutations and their epistasis are competitor-dependent.
- Bacteriophage [Formula: see text] heterogeneity evolved only when the fitness landscape was simulated as shifting.
- Landscape deformation during adaptation was directly measured.
Conclusions:
- Fitness landscapes dynamically change during adaptation, opening new adaptive pathways.
- Dynamic landscape evolution, not a static landscape, drives bacteriophage [Formula: see text] heterogeneity and speciation.
- This study provides empirical support for adaptive dynamics theory and demonstrates landscape plasticity's role in evolution.
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