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Population genetics of partial male-sterility and the evolution of monoecy and dioecy

Heredity volume 41, pages 137153 (1978) | Download Citation



Selection on reproductive phenotype in plants is studied, using a theoretical model. Fitnesses of mutant phenotypes with altered male and female fertility are derived, assuming an initially hermaphrodite or monoecious population with no self-incompatibility mechanism, with partial self-fertilisation, and with some inbreeding depression. These fitness expressions are used to derive conditions for the spread of such mutations, in terms of the minimum increase in opposite-sex fertility that will give a phenotype with reduced male or female fertility a selective advantage over the original type, taking into account the effect on the selfing rate of altering the sex phenotype. Conditions for polymorphism are also obtained. The conditions are used to study the evolution of dioecy from monoecy, and the evolution of gynomonoecy and monoecy from the hermaphrodite state.


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  1. School of Biological Sciences, University of Sussex, Falmer, Sussex BN1 9QG

    • D Charlesworth
    •  & B Charlesworth


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