PNNL

Abstract

Nearly three billion years ago, photosynthetic cyanobacteria transformed Earth’s atmosphere from oxygen-poor to oxygen-rich, enabling the evolution of complex life (1). Microbes shaped our evolutionary origins and their vast impact continues: they are essential constituents of animals and plants and are the most widespread, abundant, and diverse life forms on our planet. Microbial activities enable life but can also imperil it, through unwelcome effects like greenhouse gas production and disease. With a rapidly growing population, centuries of land use, and a changing climate, our planet faces extraordinary challenges. Given their fundamental roles in agriculture, energy production, and the health of our oceans, forests, and human population, understanding the collective activities of Earth’s microbes has never been more crucial.