Publications by authors named "Thais N C Vasconcelos"

Stingless bees are major flower visitors in the tropics, but their foraging preferences and behavior are still poorly understood. Studying stingless bee interactions with angiosperms is methodologically challenging due to the high tropical plant diversity and inaccessibility of upper canopy flowers in forested habitats. Pollen DNA metabarcoding offers an opportunity of assessing floral visitation efficiently and was applied here to understand stingless bee floral resources spectra and foraging behavior.

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Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide.

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Premise: There is little direct evidence linking floral development and pollination biology in plants. We characterize both aspects in plain and ornamented flowers of Trimezieae (Iridaceae) to investigate how changes in floral ontogeny may affect their interactions with pollinators through time.

Methods: We examined floral ontogeny in 11 species and documented pollination biology in five species displaying a wide range of floral morphologies.

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Species of plants with different life history strategies may differ in their seed dispersal mechanisms, impacting their distribution and diversification patterns. Shorter or longer distance dispersal is favored by different dispersal modes, facilitating (or constraining) population isolation, which can, in turn, impact speciation and species range sizes. While these associations are intuitive, few studies have explicitly tested these hypotheses for large clades of angiosperms.

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Mountains are among the most biodiverse areas on the globe. In young mountain ranges, exceptional plant species richness is often associated with recent and rapid radiations linked to the mountain uplift itself. In ancient mountains, however, orogeny vastly precedes the evolution of vascular plants, so species richness has been explained by species accumulation during long periods of low extinction rates.

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Worldwide distributed tropical savannas were established only in the Miocene, with climatic cooling and rise of C4 grasses. However, there is evidence for an earlier presence of savanna-like vegetation in southern parts of South America. Here we investigated the biogeographic history of a clade of solitary bees which have endemic groups in areas covered by savannas and other types of open vegetation as well as forested areas.

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Eugenia has a pantropical distribution and comprises ca. 1000 species found mostly in the Neotropics. Recent DNA based phylogenies show that unusual flower morphology of 'eugenioid' collections, e.

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Myrcia is the largest exclusively Neotropical genus of the plant family Myrtaceae with c. 770 species. Although several studies have elucidated the relationships within particular sections of the genus, to date no phylogeny has been produced that includes a broad taxonomic and geographic representation.

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The value of natural history collections for conservation science research is increasingly recognized, despite their well-documented limitations in terms of taxonomic, geographic, and temporal coverage. Specimen-based analyses are particularly important for tropical plant groups for which field observations are scarce and potentially unreliable due to high levels of diversity-amplifying identification challenges. Specimen databases curated by specialists are rich sources of authoritatively identified, georeferenced occurrence data, and such data are urgently needed for large genera.

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Changes in floral morphology are expected across evolutionary time and are often promoted as important drivers in angiosperm diversification. Such a statement, however, is in contrast to empirical observations of species-rich lineages that show apparent conservative floral morphologies even under strong selective pressure to change from their environments. Here, we provide quantitative evidence for prolific speciation despite uniform floral morphology in a tropical species-rich tree lineage.

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Background And Aims: Comparative floral ontogeny represents a valuable tool to understand angiosperm evolution. Such an approach may elucidate subtle changes in development that discretely modify floral architecture and underlie reproductive lability in groups with superficial homogeneous morphology. This study presents a comparative survey of floral development in Eugenia (Myrtaceae), one of the largest genera of angiosperms, and shows how previously undocumented ontogenetic trends help to explain the evolution of its megadiversity in contrast to its apparent flower uniformity.

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Myrteae (c. 2500 species; 51 genera) is the largest tribe of Myrtaceae and an ecologically important groups of angiosperms in the Neotropics. Systematic relationships in Myrteae are complex, hindering conservation initiatives and jeopardizing evolutionary modelling.

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Premise Of The Study: Floral display describes the effect of flower size combined with the number of flowers per inflorescence. There is strong evidence that a floral-display trade-off operates under energetic constraint, with few-flowered inflorescences likely to have larger flowers than many-flowered inflorescences. Flower size can be estimated by different variables; thus, we propose that the variable for flower size that is most highly (negatively) correlated with the number of flowers per inflorescence will also be the best estimate of floral cost.

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