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Evolvability of the Genotype-Phenotype Relation in Populations of Self-Replicating Digital Organisms in a Tierra-Like System

  • Attila Egri-Nagy
  • Chrystopher L. Nehaniv
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2801)

Abstract

In other Tierra-like systems the genotype is a sequence of instructions and the phenotype is the corresponding executed algorithm. This way the genotype-phenotype mapping is constrained by the structure of a creature’s processor, and this structure was fixed for an evolutionary scenario in previous systems. Our approach here is to put the mapping under evolutionary control. We use a universal processor (analogous to a universal Turing-machine) and put the structural description of the creature’s processor as well as the instruction set of the actual processor into the organism’s genome. The life-cycle of an organism begins with building its actual processor, then the organism can start executing instructions in the rest of its genome with the newly built processor. Since the definitions of the processors and instruction sets are in the genome, they are subject to mutations and heritable variation enabling their evolution. In this work we investigate the evolutionary development of the processor structures. In evolving populations, changes in the components (registers, stacks, queues), variations in instruction-set size and the redefinition of the instructions can be observed during experiments.

Keywords

Descriptive Part Executable Code Gestation Time Replication Algorithm Actual Processor 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2003

Authors and Affiliations

  • Attila Egri-Nagy
    • 1
  • Chrystopher L. Nehaniv
    • 1
  1. 1.Department of Computer Science, Faculty of Engineering and Information SciencesUniversity of HertfordshireHatfield, HertfordshireUnited Kingdom

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