The phylogeny of a mutualism: evolution and coadaptation between Trollius and its seed-parasitic pollinators

摘要: Interactions between seed-parasitic pollinators and their hosts provide useful model systems for the analysis of evolution mutualism potential coevolution plants insects. Here I present systematics, pollination ecology one these interactions. have documented analysed phylogenetic geographic associations Trollius (Ranunculaceae: 18 spp.) Chiastocheta (Diptera: Anthomyiidae; 17 spp.), a host-specific genus flies that pollinate host to varying extent. Their interactions are usually facultative mutualisms, but in specialized T. europaeus three fly species obligate mutualists fourth is an antagonist. The distribution patterns among suggest evolved with five highly derived species, secondarily colonized four more primitive taxa parts ranges overlapped primary hosts. In general, specificity maintained primarily through allopatry, colonization occurring regions overlap parapatric taxa. Fly speciation has occurred both within Cospeciation not evident, convergent flowers several traits, viz. orange sepals, elongated staminodia increased carpel number per flower, may be result Chiastocheta.