The idea, she explained, is to simplify one aspect of the hugely complex search for alien life . “We do know that the Earth's early biosphere did have this big component of it that was producing methane and consuming methane,” Nicholson said. The team also speculated that resource competition on alien worlds would likely favor methanogens that are smaller and longer-lived, which could outcompete similar species that are shorter-lived, larger, or require more energy. “You could have different life forms in your ocean and they would look the same in terms of a biosignature,” Nicholson said. It almost frees us up from making too many assumptions of what alien life would look like, because how are we going to know?”