justicemy

There was light. But then what happened? How did life arise on the third rocky planet orbiting the unremarkable star at the center of our solar system? Humans have been wondering about the answer to that question probably almost as long as we've been able to wonder. In recent decades scientists have made some gains in understanding the conceivable mechanisms, gradually settling on a possible picture of our origins in the oceans. The idea was that hydrothermal vents at the bottom of the seas, protected from cataclysms rending the surface four billion years ago, delivered the necessary energy and could have sustained the molecules needed. Perhaps not. Water was a necessary ingredient, surely, but that doesn't mean we sprang from oceans, according to researchers Martin J. Van Kranendonk, David W. Deamer and Tara Djokic in our cover story, “ Life Springs .” Oceans, they write, might have spread the needed molecules too quickly for cell membranes and functions to occur. Inst