Related Experiment Video
Updated: Jun 3, 2026
15:00
Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli
Published on: August 18, 2023
Second-order selection for evolvability in a large Escherichia coli population
Robert J Woods1, Jeffrey E Barrick, Tim F Cooper
1Department of Zoology, Michigan State University, East Lansing, MI 48824, USA.
Science (New York, N.Y.)
|March 19, 2011
Summary
Competition between asexual lineages can drive evolutionary potential. Surprisingly, clones destined to win had lower initial fitness, suggesting adaptation potential, not immediate benefit, determined long-term success in Escherichia coli evolution.
Area of Science:
- Evolutionary biology
- Microbial evolution
- Genetics
Background:
- Asexual lineages compete, potentially favoring traits for future adaptation.
- Understanding the drivers of evolutionary success is crucial in experimental evolution.
Purpose of the Study:
- To test if competition among asexual lineages selects for greater evolutionary potential.
- To investigate the relationship between immediate competitive fitness and long-term evolutionary success.
Main Methods:
- Revived a frozen Escherichia coli population from a long-term experiment.
- Compared fitness and evolutionary trajectories of four distinct clones.
- Replayed evolutionary experiments multiple times to assess adaptation potential.
Main Results:
- Clones with mutations that eventually dominated had lower initial competitive fitness than those that went extinct.
- The eventual winners possessed a greater capacity for subsequent adaptation.
- Genetic interactions appeared to diminish the advantages of certain mutations in the outcompeted clones.
Conclusions:
- Immediate competitive fitness does not necessarily predict long-term evolutionary success in asexual populations.
- Evolutionary potential, or the capacity for future adaptation, is a key factor in determining lineage survival and dominance.
- Complex genetic interactions can influence the relative success of different evolutionary trajectories.
Related Concept Videos
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...
01:26Evolutionary Processes in Microbes
Microbial evolution occurs rapidly due to short generation times and a variety of genetic processes, including horizontal gene transfer, mutation, recombination, and genetic drift. These mechanisms collectively enable microbes to adapt swiftly to changing environments.Horizontal gene transfer (HGT) allows genes to move between different species and occurs through three main mechanisms: conjugation, transformation, and transduction. Conjugation involves direct cell-to-cell contact for DNA...
01:27Chemotaxis in E. coli
Chemotaxis in Escherichia coli is a sensory-driven motility mechanism that enables bacteria to navigate chemical gradients, moving toward beneficial environments while avoiding harmful conditions. This process relies on a signal transduction system integrating external chemical cues with flagellar motor control.Chemoreceptors and Signal DetectionE. coli detects chemical gradients through methyl-accepting chemotaxis proteins (MCPs), which are membrane-bound chemoreceptors that sense attractants...
01:23Stringent Response in E. coli
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
00:57Antibiotic Selection
Overview