The purpose of sex

In previous work (In Search For High Performance, Proc. International Conf. on Expert Systems for Development, Asian Inst. of Technol., Bangkok, 1994, and A Framework for Evolutionary Computation, The Third Turkish Symp. on Artificial Intelligence and Neural Networks, Ankara, 1994) I have presented a formalised model of evolution. Now I show how this model can be used to explain why sexual reproduction is superior to asexual reproduction. The current view is that sexual reproduction is needed to fight disease. I show that there is a more fundamental reason for sexual reproduction to exist; sexual reproduction enables, in contrast to asexual reproduction, an efficient and adaptive control of the element of randomness that by necessity is involved in the construction of a new system