Effective Fitness as an Alternative Paradigm for
Evolutionary Computation I: General Formalism
Genetic Programming and Evolvable Machines, 1 (4):
363--378 (October 2000)DOI: doi:10.1023/A:1010017207202
Abstract
In evolutionary computation the concept of a fitness
landscape has played an important role, evolution
itself being portrayed as a hill-climbing process on a
rugged landscape. In this article we review the recent
development of an alternative paradigm for evolution on
a fitness landscape-effective fitness. It is shown that
in general, in the presence of other genetic operators
such as mutation and recombination, hill-climbing is
the exception rather than the rule; a discrepancy that
has its origin in the different ways in which the
concept of fitness appears-as a measure of the number
of fit offspring, or as a measure of the probability to
reach reproductive age. Effective fitness models the
former not the latter and gives an intuitive way to
understand population dynamics as flows on an effective
fitness landscape when genetic operators other than
reproductive selection play an important role.
Additionally, we will show that when the
genotype-phenotype map is degenerate, i.e. there exists
a synonym symmetry, it can be used to quantify the
degree of symmetry breaking of the map, thus allowing
for a quantitative explanation of phenomena such as
self-adaptation, bloat and evolutionary robustness.