To understand how the first cells transported ions across their membranes, researchers supported by the NASA Exobiology and Evolutionary Biology (Exo/Evo) program are studying simple channels used by fungi to kill off bacteria. The ability to shuffle ions in and out of a cell is clearly vital to life as we know it, but how the necessary membrane channels originated is a mystery. Andrew Pohorille, of NASA’s Ames Research Center, and his team are now studying how these simple “tunnels” could have developed the ability to regulate the flow of ions through them. A better understanding of ion channels could provide valuable information about how the first living cells developed on Earth.