Chemical Genetic Algorithms -- Coevolution between Codes and Code Translation

Hideaki Suzuki1 Hidefumi Sawai2

1ATR, Human Information Science Laboratories, Kyoto 619-0288 Japan
2Communications Research Laboratory, Kyoto 619-0289 Japan

Abstract:

A chemical genetic algorithm  (CGA) in which several types of molecules (information units) react with each other in a cell is proposed. Translation from codons (short substrings of bits) in DNA to amino acids (real value units) is specified by a particular set of translation molecules created by the reaction between tRNA units and amino acid units. This adaptively changes and optimizes the fundamental genotype-phenotype mapping  during evolution. Through the struggle between cells containing a DNA unit and small molecular units, the codes in DNA and the translation table described by the small molecular units coevolve, and a specific output function (protein), which is used to evaluate a cell's fitness, is optimized. To demonstrate the effectiveness of the CGA, the algorithm is applied to a set of deceptive problems, and the results by using the CGA are compared to those by using a simple GA. It is shown that the CGA has far better performance for the tested functions than the conventional simple GA.



Russell Standish
2002-11-13