Complex structures produced by noncatalyzed multi-step chemical processes must have highly probable origins and assembly routes. Within any frame of reference, life is easily the most-complex self-assembled structure known to man. It is not possible to calculate a finite time for biogenesis by statistical mechanics, but the abundance of life makes it reasonable to propose an accelerating principle of nature that naturally shortened the time for cell formation to a billion years or less. This hypothetical principle, which I have called valence-orbital bias, is thought to be responsible for the discrepancy between statistics and observation, and carries with it, as a conditio sine qua non, multiple origins of life.
The new concept resolves the differences between the predictions based on statistical mechanics and the relatively rapid appearance of life during the post-accretion period. It suggests as well that species and variants, the units of propagation, may also have been the units of evolution. Produced in profusion by chemistry, the origins are culled by natural selection, whereby failure means extinction, not adaptation. Biodiversity, thus, becomes a direct consequence of chemistry without positive feedback from the environment and without a constructive role for mutation.