Analysis dates emergence of photosynthesis

Abstract

Photosynthesis may have evolved about half a billion years before oxygen became abundant in Earth’s atmosphere, a new study suggests ( Proc. R. Soc. B 2021, DOI: 10.1098/rspb.2021.0675 ). This discovery updates the timing of one of the most important events in the planet’s history. Photosynthetic plants and bacteria use sunlight, water, and carbon dioxide to fuel their metabolisms, producing oxygen along the way. The evolution of oxygen-generating photosynthesis “is probably the single most important event that ever occurred on Earth, aside from the origin of life itself,” says Gregory Fournier, a geobiologist at the Massachusetts Institute of Technology who led the work. Scientists agree that photosynthesis evolved in microbes called cyanobacteria , but it’s not clear when. Studies suggest that photosynthesis evolved 500 million–1 billion years before the Great Oxygenation Event (GOE), which occurred about 2.4 billion years ago, when cyanobacteria drove a sharp increase in O 2 in