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Related Experiment Video

Updated: Jul 5, 2026

Procedure for Adaptive Laboratory Evolution of Microorganisms Using a Chemostat

Procedure for Adaptive Laboratory Evolution of Microorganisms Using a Chemostat

Published on: September 20, 2016

Variation in the reversibility of evolution.

H Teotónio¹, M R Rose

¹Department of Ecology and Evolutionary Biology, University of California, Irvine 92612, USA. ht227@cam.ac.uk

|December 2, 2000

Summary

Adaptive evolution can reverse in fruit flies, but it

Area of Science:

Evolutionary biology
Population genetics

Background:

Adaptive evolution's reversibility is debated, with microbial studies yielding mixed results.
Reverse evolution in sexual populations remains understudied despite potential differences from asexual populations.

Purpose of the Study:

To investigate the reversibility of adaptive evolution in sexually reproducing populations of Drosophila melanogaster.
To determine if previous evolutionary history influences the rate and occurrence of reverse evolution.

Main Methods:

25 diverged Drosophila melanogaster populations were returned to a common ancestral environment.
These populations were maintained for 50 generations to observe evolutionary changes.

Main Results:

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Last Updated: Jul 5, 2026

Procedure for Adaptive Laboratory Evolution of Microorganisms Using a Chemostat

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Published on: September 20, 2016

Following the Dynamics of Structural Variants in Experimentally Evolved Populations

Following the Dynamics of Structural Variants in Experimentally Evolved Populations

Published on: February 3, 2023

Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli

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Reverse evolution back to the ancestral state was observed, but it was not universal across all populations.

The success of reverse evolution depended on the specific character and the population's prior evolutionary history.

Hybrid populations did not exhibit a higher propensity for reverse evolution, indicating genetic variation was not the primary limiting factor.

Conclusions:

Adaptive reverse evolution is a contingent process in sexually reproducing organisms.
Only 50 generations of sexual reproduction were sufficient for some populations to undergo reverse evolution, but not all.