2025-02-20 マックス・プランク研究所
Mutation and selection interact, leading mutation to become biased toward adaptive outcomes. Central to this is lineage-level selection: bacterial lineages (connected nodes) were required to repeatedly evolve between two phenotypic states. Mutational transitions were initially unreliable, leading to lineage death and replacement by more successful competitors. Final surviving lineages evolved mutation-prone sequences in a key gene underpinning the phenotypes, enabling rapid transitions between states.
© GCO/MPG (Paul B. Rainey/ Michael Barnett, MPI EvolBio)
<関連情報>
- https://www.mpg.de/24229222/0220-limn-insights-into-evolutionary-dynamics-153345-x?c=2249
- https://www.science.org/doi/10.1126/science.adv4087
進化を可能にする進化可能性 マルチレベルの集団構造により、バクテリアは適応性を進化させることができる Enabling evolvability to evolve A multilevel population architecture enables bacteria to evolve increased adaptability
Edo Kussell
Science Published:20 Feb 2025
Abstract
Evolvability, or the capacity to generate adaptive phenotypic variation, can itself evolve in response to selection (1). Species that evolve too slowly may be unable to adapt to environmental change and are more likely to go extinct than faster-evolving species. Yet what it takes to get evolvability to evolve, in nature or in the lab, has remained puzzling. For example, many generations might be needed for natural selection to change a species’ ability to adapt. Higher evolvability can result in lower heritability, a cornerstone of natural selection’s ability to act, and the same degree of evolvability might not suit all traits equally. On page 840 of this issue, Barnett et al. (2) describe how experimental evolution can yield increased evolvability by localized hypermutation in populations of bacteria exposed to an alternating selection regime, akin to the regularly fluctuating conditions that pathogenic bacteria experience moving from one host to another.
