Title: Genetic Invariance:
A New Paradigm for Genetic Algorithm Design

Author:	Joseph Culberson

Date: June 1992

University of Alberta Technical Report TR92-02

Abstract:

This paper presents some experimental results and analyses of the
gene invariant genetic algorithm(GIGA). Although a subclass of the
class of genetic algorithms, this algorithm and its variations
represent a unique approach with many interesting results.  The
primary distinguishing feature is that when a pair of offspring are
created and chosen as worthy of membership in the population they
replace their parents.  With no mutation this has the effect of
maintaining the original genetic material over time, although it is
reorganized.

In this paper no mutation is allowed.  The only genetic operator used
is crossover.  Several crossover operators are experimented with and
analyzed.  The notion of a family is introduced and different
selection methods are analyzed.

Tests using simple functions, the De Jong five function test suite
and several deceptive functions are reported.  GIGA performs as well
as traditional GAs, and sometimes better.  The evidence indicates
that this method makes more effective use of the crossover operator,
in part because it never loses genetic material and thus has greater
scope for recombination.

A new view of crossover search space structures and approaches to
analysis are presented.  Traditional methods of analysis for GAs do
not seem to apply since GIGAs cannot be said to give increased trials
to the best schemata in the usual sense.  However, the analysis of
crossover search space structures may have applications in
traditional GA analysis.

Keywords: genetic algorithms, gene invariance,
deception analysis, simulation, crossover analysis

See also:
Michael Lewchuk, Master's Thesis;
"Genetic Invariance: A New Approach to Genetic Algorithms"
April 1992 Technical Report TR92-05

Joseph Culberson; "GIGA Program Description and Operation"
June 1992 Technical Report TR92-06

Anonymous ftp ftp.cs.ualberta.ca pub/TechReports

Queries: email joe@cs.ualberta.ca
