Predation on pollinators promotes coevolutionary divergence in plant-pollinator mutualisms.
Coevolution of plants and pollinators has been suggested as a mechanism driving diversification of plant-pollinator mutualisms. There is increasing recognition that predators or competitors can influence the abundance and behavior of pollinators and indirectly affect the fitness of plants. However, existing theories on plant-pollinator diversification focus exclusively on mutualistic interactions between plants and pollinators. Here we used simulations to evaluate whether predation on pollinators promotes coevolutionary diversification of plant-pollinator mutualisms. We developed an individual-based simulation model in which the blooming season of plants and the active seasons of pollinators and predators can evolve. In simulations without predators, plant-pollinator coevolution caused diversification in blooming/active seasons for both plants and pollinators, but this diversification resulted in polymorphisms, not speciation. The introduction of predators promoted a split of plant and pollinator populations into reproductively isolated subpopulations with corresponding blooming and active seasons or a directional shift of blooming and active seasons, increasing the possibility of plant-pollinator cospeciation. This result suggests that predation on pollinators can promote sympatric and allopatric divergence of plant-pollinator mutualisms. Joint action of antagonistic and mutualistic interactions may be fundamentally important for diversification in coevolutionary interactions.
Graduate School of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan.
Kotaro
K
Kagawa
Gaku
G
Takimoto
D000818:Animals; D005075:Biological Evolution; D005298:Fertility; D008954:Models, Biological; D018521:Plant Physiological Phenomena; D054817:Pollination / Q000502:physiology*; D011156:Population Density; D011235:Predatory Behavior; D012098:Reproduction; D013559:Symbiosis