Mutation rate: some biological and biochemical considerations.

This article discusses ideas about the ways in which the high fidelity of DNA replication is achieved: base selection, exonucleolytic editing, and postreplicative proofreading. I also review possible mechanisms for the enhanced mutation rate associated with SOS induction. The concept of environmental control of mutation rate and other modes of genetic variation is also considered from the point of view that SOS induction is an example of "genetic revolution".