A geological timescale for bacterial evolution and oxygen adaptation

Structured Abstract
INTRODUCTION
Microbial life dominates the biosphere, but a timescale of early microbial evolution has proven elusive as a result of an inadequate fossil record. The lack of maximum age calibrations—the earliest point in time at which a given group might have emerged—is particularly problematic. However, the geochemical record bears the imprint of microbial metabolism through time, providing a complementary source of information. A pivotal event in this history was the Great Oxidation Event (GOE) ~2.43 to 2.33 billion years ago (Ga), which marked a substantial increase in atmospheric oxygen. This transition, driven by the evolution of cyanobacterial oxygenic photosynthesis and carbon burial, transformed the biosphere from predominantly anoxic to oxic, causing widespread adaptation to oxygen. In this study, we used the temporal link between atmospheric oxygenation and the evolutionary spread of aerobic metabolism to calibrate the phylogeny of the bacterial domain.
https://www.science.org/doi/10.1126/science.adp1853