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C. FERREIRA In A. Abraham, J. Ruiz-del-Solar, and M. Köppen (eds), Soft Computing Systems: Design, Management and Applications, pp. 153-162, IOS Press, Netherlands, 2002. Analyzing the Founder Effect in Simulated Evolutionary Processes Using Gene Expression Programming Genetic Programming   As simple replicators, the ramified structures of GP are tied up in their own complexity: on the one hand, bigger, more complex structures are more difficult to handle during reproduction and, on the other, the introduction of genetic variation can only be done at the tree level and, therefore, must be done carefully so that valid structures are created. For instance, the tree-specific recombination is practically the only source of genetic variation used in GP for it allows the exchanging of sub-trees and, therefore, always produces valid structures. But the implementation of other operators, like the equivalent of the natural high-performing point mutation, is unproductive as most mutations would have resulted in syntactically incorrect structures. Obviously, the implementation of other operators such as transposition or inversion raises similar difficulties. In fact, Koza [9] describes two other tree-specific operators, permutation and mutation, but they are seldom used in GP. Home | Contents | Previous | Next