Coevolution of Machines and Tapes

A problem of self-referential paradox and self-reproduction is discussed in a network model of machines and tapes. A tape consists of a bit string, encoding function of a machine. Tapes are replicated when it is attached by an adequate machine. Generally, a tape is replicated but it may be di erent from the original one. In this paper, external noise evolves diversity in a system. New reaction pathway induced by external noise will be reproduced deterministically by an emerging autocatalytic network. Hence it will remain stable after external noise is turned o . Low external noise develops a minimal self-replicative loop. When external noise is elevated, a more complex network evolves, where a core structure emerges. Tapes in a core network can be bifurcated into either a RNAlike or a DNA-like tape with respect to its usage in an autocatalytic loop.