English

Some Techniques for the Measurement of Complexity in Tierra

Adaptation and Self-Organizing Systems 2009-09-25 v1 Populations and Evolution

Abstract

Recently, Adami and coworkers have been able to measure the information content of digital organisms living in their {\em Avida} artificial life system. They show that over time, the organisms behave like Maxwell's demon, accreting information (or complexity) as they evolve. In {\em Avida} the organisms don't interact with each other, merely reproduce at a particular rate (their fitness), and attempt to evaluate an externally given arithmetic function in order win bonus fitness points. Measuring the information content of a digital organism is essentially a process of counting the number of genotypes that give rise to the same phenotype. Whilst Avidan organisms have a particularly simple phenotype, Tierran organisms interact with each other, giving rise to an ecology of phenotypes. In this paper, I discuss techniques for comparing pairs of Tierran organisms to determine if they are phenotypically equivalent. I then discuss a method for computing an estimate of the number of phenotypically equivalent genotypes that is more accurate than the ``hot site'' estimate used by Adami's group. Finally, I report on an experimental analysis of a Tierra run.

Keywords

Cite

@article{arxiv.nlin/0001009,
  title  = {Some Techniques for the Measurement of Complexity in Tierra},
  author = {Russell K. Standish},
  journal= {arXiv preprint arXiv:nlin/0001009},
  year   = {2009}
}

Comments

5 pages; 1 figure; European Conference on Artificial Life