Abstract
Profound advances in the fields of molecular biology in recent years have enabled the elucidation of cell structure and function in detail previously unimaginable. The unexpected levels of complexity revealed at the molecular level have further strained the concept of the random assembly of a self-replicating system. At the same time, the recent discovery of fossil algae and stromatolites (primitive colonies of cyanobacteria) from as early as the Precambrian, have reduced the time for development of the first cell as much as tenfold. Together with implications of this for the oxidative state of the primitive atmosphere, these developments will force researchers to rethink many fundamental ideas pertaining to current models of the origin of life on Earth. The evidence for the nature of the primitive atmosphere is examined and the possibility of ribonucleic acid (RNA) as the first self-replicating molecule is evaluated. The focus is then on DNA, proteins and the first cells.