Replication of DNA is essential for the propagation of life. It is somewhat surprising then that, despite the vital nature of this process, cellular organ-isms show a great deal of variety in the mechanisms that they employ to ensure appropriate genome duplication. This diversity is manifested along classical evolutionary lines, with distinct combinations of replicon architec-ture and replication proteins being found in the three domains of life: the Bacteria, the Eukarya and the Archaea.
