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Summary: Evolving Better Representations through
Selective Genome Growth
Lee Altenberg
Institute of Statistics and Decision Sciences, Duke University,
Durham, NC 277080251 U.S.A. Internet: altenber@acpub.duke.edu
Abstract---
The choice of how to represent the search space for
a genetic algorithm (GA) is critical to the GA's per
formance. Representations are usually engineered by
hand and fixed for the duration of the GA run. Here a
new method is described in which the degrees of free
dom of the representation --- i.e. the genes -- are in
creased incrementally. The phenotypic effects of the
new genes are randomly drawn from a space of differ
ent functional effects. Only those genes that initially
increase fitness are kept. The genotypephenotype map
that results from this selection during the construction
of the genome allows better adaptation. This effect is
illustrated with the NK landscape model. The resulting
genotypephenotype maps are much less epistatic than
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