Natural selection in microbes unfolds through births, deaths, mutation, selection, and competition, with faster generation times enabling rapid evolutionary change compared to long-lived organisms.

Microbial evolution experiments provide accelerated insights into natural selection, adaptation, and dynamics of evolutionary change that exceed what’s observable in larger, slower species.

Early pioneers like William Dallinger showed microbes could evolve under gradually increasing temperatures, foreshadowing modern evolution experiments.

LTEE findings reveal divergent trajectories among replicate populations, such as Ara-2 splitting into two lineages and Ara-3 gaining citrate metabolism, suggesting potential speciation events.

The Long-Term Evolution Experiment, started by Lenski in 1988 and approaching 80,000 generations of E. coli, demonstrates ongoing adaptation over tens of thousands of generations in a constant environment.

Whole-genome sequencing has become a powerful tool to link genotype to phenotype, enabling comparisons between ancestral and frozen generations to track evolutionary changes over time.

Global research uses microbial evolution to study predation, starvation, and the emergence of multicellularity from single-celled ancestors, among other topics.

Modern methods like MEGA plates allow rapid evolution under gradually increasing antibiotic concentrations, exposing trade-offs between resistance level and growth rate and how gradual gradients guide adaptation.

Darwin’s early work lacked microbes, but microbes later became central to testing and illustrating evolution in laboratories.