The Origins of Life

Twenty-five years ago, Francis Crick, who co--discovered the structure of DNA, published a provocative book titled Life Itself: Its Origin and Nature. Crick speculated that early in Earth’s history a civilization from a distant planet had sent a spaceship to Earth bearing the seeds of life. Whether or not Crick was serious about his proposal, it dramatized the difficulties then plaguing the theory that life originated from chemical reactions on Earth. Crick noted two major questions for the theory. The first one—seemingly unanswerable at the time—was how genetic polymers such as RNA came to direct protein synthesis, a process fundamental to life. After all, in contemporary life-forms, RNA translates genetic information encoded by DNA into instructions for making proteins...more here