Artificial Life VI

Introduction of Structural Dissolution into Langton's Self-Reproducing Loop

Hiroki Sayama
Department of Information Science, University of Tokyo


The phenomenon of death, or disappearance of life, has two aspects. One is failure in the function of life and the other is dissolution of the structure of life. In order to examine the significance of the latter aspect, the author contrived a "structurally dissolvable self-reproducing (SDSR) loop" by introducing the capability of structural dissolution into Langton's self-reproducing (SR) loop in which death as functional failure has already been installed. To be more specific, a dissolving state '8' was introduced into the set of states of the CA, besides other modifications to Langton's transition rules. Through this improvement, the SDSR loop can dissolve its own structure when faced with difficult situations such as a shortage of space for self-reproduction. This mechanism (disappearance of a subsystem of the whole system) induces, for the first time, dynamically-stable and potentially evolvable behavior into the colony of SDSR loops.

SDSR Loop Homepage

A simple CA simulator "LoopS" (ver 1.0), for observing the behavior of both SR/SDSR loops, is now available on the following ftp site. This program is made for UNIX platforms provided with a standard C compiler and X11 libraries. In addition, you can utilize it as a general-purpose simulator of 5-neighbor 9-state CA if several options are specified. Click here to download LoopS-1.0.tar.gz

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