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Mutualisms are a basic component of multispecies communities and play crucial roles in the functioning of ecosystems. Early theory on mutualisms, however, predicted that mutualistic interactions could be destabilizing because the interdependent augmentation of mutualists caused their population explosion. Later studies suggested that additional factors, such as costs or saturating benefits of mutualisms and antagonistic interactions that exploited mutualisms, could dampen the destabilizing effect of mutualisms. In plant–pollinator mutualisms, predation on pollinators is a common form of antagonistic interactions, although its effects on the stability of plant–pollinator mutualisms have remained poorly understood. Here, using a mathematical model, we consider whether predation on pollinators can stabilize plant–pollinator mutualisms. We show that predation on pollinators does not stabilize an inherently unstable plant–pollinator mutualism, but the modification of pollinator behavior to avoid predation can stabilize the mutualism. Our results contribute to a better understanding of how predator‐induced behavior modification in pollinators can affect the maintenance of plant–pollinator mutualisms. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the mechanisms of rapid adaptive radiation has been a central problem of evolutionary ecology. Recently, there is a growing recognition that hybridization between different evolutionary lineages can facilitate adaptive radiation by creating novel phenotypes. Yet, theoretical plausibility of this hypothesis remains unclear because, for example, hybridization can negate pre‐existing species richness. Here, we theoretically investigate whether and under what conditions hybridization promotes ecological speciation and adaptive radiation using an individual‐based model to simulate genome evolution following hybridization between two allopatrically evolved lineages. The model demonstrated that transgressive segregation through hybridization can facilitate adaptive radiation, most powerfully when novel vacant ecological niches are highly dissimilar, phenotypic effect size of mutations is small and there is moderate genetic differentiation between parental lineages. These results provide a theoretical basis for the effect of hybridization facilitating adaptive radiation. [ABSTRACT FROM AUTHOR]