Captured: moment life changed forever

摘要

Billions of years ago, a tiny cyanobacterium cracked open a water molecule - and let loose a poison that wrought death and destruction on an epic scale. The microbe had just perfected photosynthesis, a process that freed the oxygen trapped inside water and killed early Earth's anaerobic inhabitants. Now, for the first time, geologists have found evidence of the crucial evolutionary stage just before cyanobacteria split water. The find offers a unique snapshot of the moment that made the modern world.