Dynamic analysis of the evolution of a novel genetic system: the evolution of ciliate meiosis.

Many ciliates undergo a peculiar form of meiosis in which four haploid nuclei are produced, three are digested, and the single remaining nucleus undergoes mitosis. It is paradoxical that such a meiotic process occurs, since one could imagine several other less costly ways of producing two nuclei. Here we investigate a possible resolution of this paradox. It is shown that the spread of a selfish gene that kills the mate not containing it, provides the conditions for the spread of a costly modifier of the form of meiosis. We investigate the conditions under which the modifier can fixate.