Microbe’s Diversity Is Vast, Ancient

The cyanobacterium Prochlorococcus is arguably one of the most important organisms on the planet when it comes to supporting life. Hovering near the surface of the ocean, these microbes—a trillion trillion of them—produce half of the world’s oxygen. Given their abundance, results published today (April 24) in Science illustrating their astounding genomic diversity are not terribly surprising. But the study also uncovered genomic lineages, or “backbones,” that may have originated millions of years ago.