A new high resolution microbial time #tree calibrated using the Great Oxidation Event (GOE) ~2.33 billion years ago highlights the evolution of aerobic lifestyles in #bacteria. Most bacteria were ancestrally anaerobic (Bacillota/Firmicutes are the oldest) and the transition to an aerobic lifestyle was initiated by Cyanobacteria, which seeded #oxygen production and consumption capabilities to the broader bacterial tree over hundreds of millions of years.

https://www.biorxiv.org/content/10.1101/2023.08.08.552427v1