Incremental Commitment in Genetic Algorithms

Successful recombination in the simple GA requires that interdependent genes be close to each other on the genome. Several methods have been proposed to reorder genes on the genome when the given ordering is unfavorable. The Messy GA (MGA) is one such ‘moving-locus’ scheme. However, gene reordering is only part of the Messy picture. The MGA uses another mechanism that is influential in enabling successful recombination. Specifically, the use of partial specification (or variable length genomes) allows the individuals themselves, rather than the ordering of genes within an individual, to represent which genes ‘go together’ during recombination. This paper examines this critical feature of the MGA and illustrates the impact that partial specification has on recombination. We formulate an Incremental Commitment GA that uses partially specified representations and recombination inspired by the MGA but separates these features from the moving-locus aspects and many of the other features of the existing algorithm.