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In the traditional picture of the origins of life, the instant the first replicator pops up is a rare and fleeting moment that bootstraps the rest of evolution. This is an enormously lucky event, a fleeting spark that lights the fuse of all life. As in Greek cosmology, from a \u201cvast and dark\u201d void, chaos, was born Gaia, the primordial Earth goddess. But the work on prelife suggests there may never have been such a magic moment\u2014no singularity and no Big Biological Bang. Instead, I could see a gentle transition, a smeared boundary between chemistry and biochemistry, between \u201cprelife\u201d and life. Life had no definitive beginning but gradually came into vibrant focus from a blurred, dark origin.<\/p>\n\n\n\n
Over the eons, prelife became enriched. The richer prelife became, the more likely it was that an outbreak of life would take hold. In other words, the development of rich chemistry\u2014with enough time and space\u2014was bound to discover the right molecules to replicate. In this way, the soup of lifeless chemicals on Earth was, in effect, testing possible replicating molecules, and making it much more probable that one might eventually reach the threshold of life.<\/p>\n\n\n\n
Thus, the origin of life may not have rested on a single spark of genesis but on a chemistry that churned on Earth for hundreds of millions of years. Within the chemistry of prelife, there were opportunities for cooperation. Some sequences could have had catalytic activities, which means they increased the rate of certain prelife reactions. I could also envisage how two complementary prelife sequences could have catalyzed reactions which built each other. One molecule increased the rate at which the other was formed, and vice versa. The existence of cooperating pairs of molecules in prelife is very plausible. Indeed, replication of a single strand of RNA can be thought of this way: one strand of RNA builds a complementary strand, and so on. Thus cooperation is older than life itself.<\/p>\n\n\n\n