title: The role of birds and insects in pollination shifts of Scrophularia (Scrophulariaceae).
abstract: The mixed vertebrate-insect pollination system is rare in Holarctic plants. Phylogenetic relationships of 116 Scrophularia taxa were investigated based on two plastid (ndhF and trnL-trnF) and one nuclear (ITS) DNA regions. A wider time-calibrated analysis of ndhF sequences of the Lamiales revealed that Scrophularia diverged as early as in the Miocene (<22 Ma). Results of maximum-likelihood optimizations supported wasp pollination as the ancestral pollination system from which other systems derived (hoverfly, mixed vertebrate-insect and bird systems). Four origins for a mixed vertebrate-insect (MVI) pollination system were inferred, in which two western Mediterranean species (S. sambucifolia and S. grandiflora) and two island species (the Tirrenian S. trifoliata and the Canarian S. calliantha) were involved. S. calliantha is the only species in which a more complex MVI system, including pollination by the lizard Gallotia stehlini, has evolved. In addition, bird (hummingbird) floral traits found in the New Mexican S. macrantha appear to have been independently acquired. In contrast, we failed to find evidence for an ancient role of hummingbirds in the evolution of European Scrophularia. Indeed, paleontological data revealed that extinction of European hummingbirds (30-32 Ma) occurred earlier than the divergence of European MVI lineages of Scrophularia. In conclusion, our results showed that a role of birds in pollination of Scrophularia may not have been effective in the Miocene-Pliocene, but bird pollination that shows its origin in the Pliocene-Pleistocene is still operating independently in different islands and continents.
authors.affiliation: Área de Botánica, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s.n., 06006 Badajoz, Spain. marisanav@unex.es
authors.forename: María L
authors.initials: ML
authors.lastname: Navarro-Pérez
authors.forename: Josefa
authors.initials: J
authors.lastname: López
authors.forename: Mario
authors.initials: M
authors.lastname: Fernández-Mazuecos
authors.forename: Tomás
authors.initials: T
authors.lastname: Rodríguez-Riaño
authors.forename: Pablo
authors.initials: P
authors.lastname: Vargas
authors.forename: Ana
authors.initials: A
authors.lastname: Ortega-Olivencia
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D001717:Birds / Q000502:physiology; D002467:Cell Nucleus / Q000235:genetics; D018744:DNA, Plant / Q000145:classification* / Q000235:genetics; D005060:Europe; D035264:Flowers / Q000145:classification* / Q000235:genetics; D007313:Insecta / Q000502:physiology; D008116:Lizards / Q000502:physiology; D010802:Phylogeny; D058974:Phylogeography; D063148:Plant Dispersal; D018087:Plastids / Q000235:genetics; D054817:Pollination / Q000502:physiology*; D032266:Scrophularia / Q000145:classification* / Q000235:genetics; D013997:Time Factors
chemical_list: D018744:DNA, Plant
keywords: Bird pollination; Divergence times; Macaronesia; Mixed vertebrate-insect pollination; Scrophularia; Wasp pollination