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Science 26 February 1993:
Vol. 259. no. 5099, pp. 1282 - 1287
DOI: 10.1126/science.259.5099.1282
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Articles

Simple Systems That Exhibit Self-Directed Replication

James A. Reggia 1, Steven L. Armentrout 2, Hui-Hsien Chou 2, and Yun Peng 3

1 Department of Computer Science, Department of Neurology, and the Institute of Advance Computer Studies, A. V. Williams Building, University of Maryland, College Park, MD 20742
2 Department of Computer Science, University of Maryland, College Park, MD 20742
3 Department of Computer Science, University of Maryland at Baltimore County, Catonsville, MD 21228

Biological experience and intuition suggest that self-replication is an inherently complex phenomenon, and early cellular automata models support that conception. More recently, simpler computational models of self-directed replication called sheathed loops have been developed. It is shown here that "unsheathing" these structures and altering certain assumptions about the symmetry of their components leads to a family of nontrivial self-replicating structures, some substantially smaller and simpler than those previously reported. The dependence of replication time and transition function complexity on initial structure size, cell state symmetry, and neighborhood are examined. These results support the view that self-replication is not an inherently complex phenomenon but rather an emergent property arising from local interactions in systems that can be much simpler than is generally believed.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
The Trend Cellular Automata Programming Environment.
H.-H. Chou, W. Huang, and J. A. Reggia (2002)
SIMULATION 78, 59-75
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Simplifications of a Self-Replication Model.
K. P. Williams (1993)
Science 261, 925
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