Sylvain Takenouti（Ecole Polytechnique France）
６月２９日 （木） 午後１：３０から
理学部3号館 6階 数理生物学セミナー室
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Dimorphism of the body color is a pattern of specie of pea aphids,
Acyrthosiphon pisum. This polymorphism seems to be ESS (evolutionarily
stable strategy). On the one hand, red aphids are the preferred preys of aphids'
predator, Coccinella septempunctata, while on the other hand green ones
are the aim of parasitoids, wasps Aphidius ervi. We built a model of
the coevolution of three species, where preference of color of prey/host is
genetically determined for predators and parasitoids, and where distribution
of body color is continuous gradation between red and green. Changing the
parameters of the model, we observed monomorphism, dimorphism, or trimorphism
at equilibrium. We studied the transition of equilibrium between monomorphism
and dimorphism. We also modified the model in order to be as close as possible to
the example of pea aphids, and observed the same kind of evolution.
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