The evolutionary jumping and evolutionary breakthrough in the
evolution of masting
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Masting is intermittent and synchronized reproduction of plants. I have studied the evolutionary condition of intermittent reproduction. The intermittent reproduction realizes the large amount of seed production in mast year, however no seeds are produced subsequent several years. It means that intermittent reproduction fails to make offspring for no reproduction years. Hence trees evolve to produce seed every year. When seedlings on the forest understory can survive for several years, the disadvantage of no seed production is compensated by surviving seedling and masting evolves (Tachiki & Iwasa 2010 J. Ecol). We conclude that survivorship of seedling in understory (shade tolerance) is important factor for the evolution of masting. In this talk, I talk about the mathematical analyses of invasion condition of masting. The invasion condition of masting was analysied in the adaptive dynamics framework by assuming infinitely large population and synchronization of resident trees. As results, the evolutionary jumping was observed when intermittent reproduction evolved from annual reproduction. In addition, when population size was small and genetic drift was strong, ESS condition was destabilized and transition from an ESS point to another ESS point could occur (Evolutionary breakthrough). |
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