ARTIFICIAL SELF-REPLICATION AND EVOLUTION

Hiroki Sayama

Research on self-replicating and evolving artificial systems was founded by von Neumann in the late '50s and now is renamed "Artificial Life". Von Neumann's monumental work of self-reproducing automata and most of other succeeding works assumed uniformly arranged cellular sites and discreteness of space / time / state of each site, which is called Cellular Automata (CA).

Earlier attempts to create artificial organisms using CA may be categorized into four groups --- (1) implementation of universal constructors based on von Neumann's self-reproducing automaton, (2) search for a minimal system capable of non-trivial self-replication, (3) addition of other computational capabilities to self-replicators, and (4) realization of emergence and evolution of self-replicators. (1), (2), and (3) are efforts to implement regulated behavior (e.g. construction, self-replication, computation) manually designed according to the designer's idea, while (4) strives to obtain unexpected behavior (e.g. emergence of self-replicators or evolution) that may arise from robust or random state-transition rules.

This project belongs to the category (4), currently aiming at constructing evolutionary systems on a simple, deterministic CA space. The final goals of this project are to give some answer to the question whether the complexity-increasing evolution of artificial organisms (the evolution of their ability to do more complicated things) is attainable using CA or any artificial media, which has been an open question originally posed by von Neumann himself at the beginning of this research field.

The CA-based models proposed so far in the project are available in the subproject pages below, while the other form of self-replication models, such as self-replication in a kinematic universe, are also considered now.

Subprojects:

Structurally dissolvable self-reproducing loop & Evoloop

Self-replicating worms with shape-encoding mechanism

Papers:

H. Sayama: Self-replicating worms that increase structural complexity through gene transmission, Artificial Life VII: Proceedings of the Seventh International Conference on Artificial Life, M. A. Bedau, J. S. McCaskill, N. H. Packard and S. Rasmussen, eds., pp.21-30, 2000, MIT Press. PDF files PostScript (gzipped)

H. Sayama: A new structurally dissolvable self-reproducing loop evolving in a simple cellular automata space, Artificial Life 5:4, pp.343-365, 1999. Full text (PDF file)

H. Sayama: Spontaneous evolution of self-reproducing loops on cellular automata, InterJournal, Brief Article 236, accepted.

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