Donato Giovannelli is an assistant professor at the University of Naples “Federico II.” He travels to acid lakes and other extreme environments that are the closest thing today to what Earth was like when life began.

All the life we know is the same: carbon-based, with DNA for genes. (Okay, except for RNA viruses.) But Steven Benner says it doesn’t have to be that way. Benner is a Distinguished Fellow at the Foundation for Applied Molecular Evolution.