Abstract

The theory is presented that the sexual process is a repair mechanism which maintains redundancy within the sub-structure of hierarchical, self-reproducing organisms. In order to keep the problems within mathematically tractable limits , a simple model is introduced: a wheel with 6 spokes, 3 of them vital and 3 redundant, symbolizes the individual . Random accidents destroy spokes; the wheels replicate at regular cycles and engage periodically in pairing and repair phases during which missing spokes are copy-reproduced along the intact spokes of the partner wheel.The hierarchical structure of such a system is analysed and an ‘autonomous unit’ is defined: this is the unit of minimal hierarchical complexity which is capable of perpetuating autonomously all higher and all lower levels of the hierarchy; this is the central unit of selection.Four basic, physical parameters are isolated which determine the essential features of any eucaryotic life cycle: 1. The number of levels of the hierarchy ; 2. the relation between the phases of replication and repair ; 3. the duration of potential repair ; 4. the position of the sexual partners within the hierarchy .The evaluation of fitness components is considered in relation to trends of reproductive patterns in evolution