How did life on Earth first arise? Despite his clear articulation of the principle of evolution, Charles Darwin didn’t have a clue. In 1863, he wrote to his close friend Joseph Dalton Hooker that “it is mere rubbish, thinking, at present, of origin of life; one might as well think of origin of matter.” Today, we have more of a clue, although the details are lost to deep time.
and chemists working in the field of abiogenesis—the study of the moment when, 3 or 4 billion years ago, chemistry became life—have developed multiple plausible origin stories. In one, proto-organisms in an ancient “ ” were made of RNA molecules, which both replicated and folded into 3-D structures that could act like primitive enzymes. In a competing “ first” account, chemical reaction networks sputtered to life in the porous rock chimneys of “black smokers” on the ocean floor, powered by geothermal energy; RNA and DNA came later.
Either way, even bacteria—the simplest life forms surviving today—are a product of many subsequent evolutionary steps. The most important of these steps may have been large and sudden, not the everyday, incremental mutation and selection theorized by Darwin. These “ ” involve simpler, less complex replicating entities becoming interdependent to form a larger, more complex, more capable replicator.
We are made out of functions, and those functions are made out of functions, all the way down. As maverick biologist Lynn Margulis discovered in the 196.