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Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants
Most of the 470-million-year history of plants on land belongs to bryophytes, pteridophytes and gymnosperms, which eventually yielded to the ecological dominance by angiosperms 90 Myr ago. OurExpand
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The history of early bee diversification based on five genes plus morphology
Bees, the largest (>16,000 species) and most important radiation of pollinating insects, originated in early to mid-Cretaceous, roughly in synchrony with the angiosperms (flowering plants).Expand
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Analysis of family-level relationships in bees (Hymenoptera: Apiformes) using 28S and two previously unexplored nuclear genes: CAD and RNA polymerase II.
We analyzed a combined data set of two protein-coding nuclear genes (CAD and RNA polymerase II) and a nuclear ribosomal gene (28S D2-D4 region) for 68 bee species and 11 wasp outgroups. Our taxonExpand
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Single-copy nuclear genes recover cretaceous-age divergences in bees.
We analyzed the higher level phylogeny of the bee family Halictidae based on the coding regions of three single-copy nuclear genes (long-wavelength [LW] opsin, wingless, and elongation factor 1-alphaExpand
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Recent and simultaneous origins of eusociality in halictid bees
Eusocial organisms are characterized by cooperative brood care, generation overlap and reproductive division of labour. Traits associated with eusociality are most developed in ants, termites, paperExpand
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Pollen‐host specificity and evolutionary patterns of host switching in a clade of specialist bees (Apoidea: Diadasia)
We examined the levels of pollen-host specificity in North American Diadasia (Hymenoptera: Apoidea), a clade of specialist bees. We analysed the scopal pollen loads of 409 individuals representing 25Expand
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Tests of pre- and postpollination barriers to hybridization between sympatric species of Ipomopsis (Polemoniaceae).
The Ipomopsis aggregata species complex (Polemoniaceae) includes species pairs that hybridize readily in nature as well as pairs that meet along contact zones with no apparent hybridization.Expand
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Reproductive biology and pollination ecology of the rare Yellowstone Park endemic Abronia ammophila (Nyctaginaceae)
We examined the breeding system, reproductive output and pollination ecology of Abronia ammophila Greene, a rare and highly restricted endemic of Yellowstone National Park, Wyoming, USA. FloralExpand
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Species‐independent, geographical structuring of chloroplast DNA haplotypes in a montane herb Ipomopsis (Polemoniaceae)
Two hypotheses have been proposed to explain the occurrence of hybrid zones between red‐flowered Ipomopsis aggregata and white‐flowered I. tenuituba. Either local adaptation to hummingbird andExpand
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