ibclogo XVI International Botanical Congess


Abstract Number: 5047
Session = 15.11.7


EVOLUTION OF SELF-FERTILIZATION IN METAPOPULATIONS


J. R. Pannell, Department of Plant Sciences, Oxford OX13RB, United Kingdom


Darwin suggested that self-fertilization may evolve through selection for reproductive assurance when pollinators or mates are scarce. Such conditions are particularly likely in colonizing species, in which extinctions are balanced through the recolonization by one or a few individuals. This paper presents models that explore the implications of colony turnover for mating-system evolution. The models show that selection for selfing should increase with the extinction rate and decrease with the number of colonizing individuals. It should be greatest when the colony occupancy rate, p, is low and is much reduced when p approaches its maximum. This result may explain why many highly successful colonizers, in which p is often high, are self-incompatible. The models' predictions will be set against observed mating-system variation in different colonising species, and the sort of genetic data needed to test them will be discussed.


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