Sex and Ageing: The Role of Sexual Recombination in Longevity

1 I use a set of machines based on the concept of nested rule systems built on the a modified version of the Wolfram elemental cellular automata to investigate the role of recombination in providing resistance to ageing. Class III and class IV machines are observed to respond differently to recombination. Class IV machines show recombinational centring in their neutral networks whereas class III machines respond negatively to recombination. Rule 110 shows a unusual response to recombination. Recombination selects for resistance to recombination, the population moves to regions of genome space with high redundancy, this results in organisms with highly robust genomes, more likely to complete development and to be long lived. The increase in longevity may be sufficient to compensate for the costs of sex, including the two fold cost of sex, through increased reproductive potential in long lived organisms requiring long maturation times. Large complex species should therefore be resistant to invasion by asexual mutants whereas small simple organisms with early maturation should be vulnerable to invasion by asexual forms.