Bacteria are some of the oldest and most diverse organisms on Earth. Apparently, they are also among the toughest; researchers in Mexico’s Cueva de los Cristales have isolated and cultured bacteria that have been trapped within the crystals for up to 50,000 years. These tiny creatures biding their time within a rock for millennia, but they are by no means the oldest bacteria ever isolated. Efforts have been underway for decades to isolate microorganisms from rock or other materials. One early attempt aimed to culture bacteria from within Permian (~289-252 mya) salt deposits. The study was beset by concerns about...