White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

The influence of mutation on population dynamics in multiobjective genetic programming

Badran, K. and Rockett, P.I. (2010) The influence of mutation on population dynamics in multiobjective genetic programming. Genetic Programming and Evolvable Machines, 11 (1). pp. 5-33. ISSN 1389-2576

[img] Text

Download (1031Kb)


Using multiobjective genetic programming with a complexity objective to overcome tree bloat is usually very successful but can sometimes lead to undesirable collapse of the population to all single-node trees. In this paper we report a detailed examination of why and when collapse occurs. We have used different types of crossover and mutation operators (depth-fair and sub-tree), different evolutionary approaches (generational and steady-state), and different datasets (6-parity Boolean and a range of benchmark machine learning problems) to strengthen our conclusion. We conclude that mutation has a vital role in preventing population collapse by counterbalancing parsimony pressure and preserving population diversity. Also, mutation controls the size of the generated individuals which tends to dominate the time needed for fitness evaluation and therefore the whole evolutionary process. Further, the average size of the individuals in a GP population depends on the evolutionary approach employed. We also demonstrate that mutation has a wider role than merely culling single-node individuals from the population; even within a diversity-preserving algorithm such as SPEA2 mutation has a role in preserving diversity.

Item Type: Article
Copyright, Publisher and Additional Information: © 2010 Springer. This is an author produced version of a paper subsequently published in Genetic Programming and Evolvable Machines. Uploaded in accordance with the publisher's self-archiving policy.
Keywords: Multiobjective genetic programming; Population collapse; Mutation; Population dynamics
Institution: The University of Sheffield
Academic Units: The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield)
Depositing User: Miss Anthea Tucker
Date Deposited: 23 Feb 2010 10:45
Last Modified: 08 Feb 2013 16:59
Published Version: http://dx.doi.org/10.1007/s10710-009-9084-3
Status: Published
Publisher: Springer
Identification Number: 10.1007/s10710-009-9084-3
URI: http://eprints.whiterose.ac.uk/id/eprint/10430

Actions (repository staff only: login required)