language: en

Simulations with an Evolvable Fitness Formula

Henrik Hautop Lund Domenico Parisi
Institute of Psychology National Research Council,
Viale Marx 15, 00137 Rome, Italy

[tel.: (+39) 6 88 94 596]

[fax : (+39) 6 82 47 37]

- DAIMI University of Aarhus,
Ny Munkegade, 8000 Aarhus C., Denmark

[tel.: (+45) 89 42 32 21]

[fax : (+45) 89 42 32 55]

e-mail: hhl@daimi.aau.dk domenico@gracco.irmkant.rm.cnr.it

Abstract The concept of a fitness formula as a property of an organism is proposed. In artificial life simulations with organisms living in an environment, the fitness formula can be interpreted as the ability of organisms to extract energy from potential food sources distributed in the environment. In simulations where the goal of the genetic algorithm is that of developing systems which exhibit a certain type of behavior in a particular environment, the fitness formula becomes an independent variable which can be manipulated in order to obtain the desired behavior. The fitness formula can be viewed as an evolvable trait of organisms, and therefore not fixed and decided by the researcher. Simulations with fixed and evolvable fitness formulae show that the fitness formula, the sensory apparatus, and the behavior of organisms may co-evolve and be co-adapted.