Related Experiment Video
Updated: Jun 24, 2026

Adaptation at the Extremes of Life: Experimental Evolution with the Extremophile Archaeon Sulfolobus acidocaldarius
Published on: June 14, 2024
The alpha-proteobacteria: the Darwin finches of the bacterial world
Thijs J G Ettema1, Siv G E Andersson
1Department of Molecular Evolution, Evolutionary Biology Center, 752 36 Uppsala, Sweden.
Abstract:
The alpha-proteobacteria represent one of the most diverse bacterial subdivisions, displaying extreme variations in lifestyle, geographical distribution and genome size. Species for which genome data are available have been classified into a species tree based on a conserved set of vertically inherited core genes. By mapping the variation in gene content onto the species tree, genomic changes can be associated with adaptations to specific growth niches. Genes for adaptive traits are mostly located in 'plasticity zones' in the bacterial genome, which also contain mobile elements and are highly variable across strains. By physically separating genes for information processing from genes involved in interactions with the surrounding environment, the rate of evolutionary change can be substantially enhanced for genes underlying adaptation to new growth habitats, possibly explaining the ecological success of the alpha-proteo-bacterial subdivision.
Related Concept Videos
Bacterial Phylum Proteobacteria
Deep Sea Microbial Ecology
Bacterial Phylum Bacteroidota
Anoxygenic Phototrophic Bacteria
Evolution of New Traits in Microbes
Other Unique Bacteria

