If life's origin was a purely natural phenomenon, why haven't scientists replicated the experiment? Actually, that's exactly what they're trying to do. The New York Times' Dennis Overbye reports on the effort to produce self-replicating RNA at the Scripps Research Institute. Overbye says RNA is the Robin-like sidekick to the Batman of biochemistry, DNA. But many researchers believe RNA figured in the DNA origin story. So is a sequel in the works?