2.5-Billion-Year-Old Fossils Predate Earth's Oxygen

Fossils of what may be the oldest sulfur-eating bacteria ever found have been discovered in rocks dating back a staggering 2.52 billion years. The fossils don't represent the oldest life on Earth by any stretch — there are fossils of microbes that are at least a billion years older — but they are the oldest of their type. Rather than using oxygen to survive, these bacteria would have turned hydrogen sulfide into sulfate (the oxidized form of sulfur), using the energy from that chemic