The Earth’s rotation has gradually slowed since its formation 4.5 billion years ago, leading to longer days. This subtle change, although imperceptible on human timescales, may have significantly influenced major ecological events. A 2021 study suggests that the Earth’s increasing day length could have impacted oxygen production by blue-green algae (cyanobacteria) during the Great Oxidation Event roughly 2.4 billion years ago.
Research led by microbiologist Gregory Dick from the University of Michigan explores how the slowdown, caused by gravitational interactions with the moon, could be linked to increased atmospheric oxygen. Historical records indicate that days were shorter—around 18 hours—1.4 billion years ago.
Cyanobacteria played a crucial role in oxygen production during this era, competing with other microorganisms in microbial mats found in places like Lake Huron. These mats exhibit timed competition for resources that may have limited oxygen production during the early Earth’s history.
Experiments and modeling showed that shifts in day length influenced photosynthesis and oxygen release from these microbes. The research indicates a connection between planetary mechanics and biological processes, linking the Earth’s rotation to vital atmospheric oxygen levels. This study highlights the fascinating interplay between Earth’s physical characteristics and its biological history and was published in Nature Geoscience.
