Self-replication

Self-replication is any behavior of a dynamical system that yields construction of an identical copy of itself. Biological cells, given suitable environments, reproduce by cell division. During cell division, DNA is replicated and can be transmitted to offspring during reproduction. Biological viruses can reproduce, but only by commandeering the reproductive machinery of cells through a process of infection. Harmful prion proteins can replicate by converting normal prions into rogue forms. Computer viruses reproduce using the hardware and software already present on computers. Self-replication in robotics has been an area of research and a subject of interest in science fiction. Any self-replicating mechanism which does not make a perfect copy will result in the creation of different variants and thus be subject to natural selection as the variants which are better at persisting in their environment will outlive and outreproduce variants which are not so suited to their environment.