Results 251 to 260 of about 38,890 (303)
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Archaefructus – angiosperm precursor or specialized early angiosperm?
Trends in Plant Science, 2003With molecular analyses indicating that angiosperms are not closely related to any other extant seed plant group, information from fossils might provide the only basis for reconstructing their origin. Therefore the description of a new Early Cretaceous angiosperm, Archaefructus, placed as the sister of all extant angiosperms, has created much debate ...
Else Marie, Friis +3 more
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Evolutionary diversification of the flowers in angiosperms [PDF]
American Journal of Botany, 2011 Angiosperms and their flowers have greatly diversified into an overwhelming array of forms in the past 135 million years. Diversification was shaped by changes in climate and the biological environment (vegetation, interaction with other organisms) and ...
P K Endress
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Polyploidy and angiosperm diversification
American Journal of Botany, 2009Polyploidy has long been recognized as a major force in angiosperm evolution. Recent genomic investigations not only indicate that polyploidy is ubiquitous among angiosperms, but also suggest several ancient genome‐doubling events. These include ancient whole genome duplication (WGD) events in basal angiosperm lineages, as well as a proposed ...
Douglas E, Soltis +9 more
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Science, 1974
Collections of well-preserved angiosperm flowers from the Middle Eocene of southeastern North America include a variety of morphological types. The first of these specimens to be studied extensively, a catkin, has yielded a great deal of structural information. Floral morphology, pollen morphology, and the nature of the peltate scales suggest that this
W L, Crepet, D L, Dilcher, F W, Potter
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Collections of well-preserved angiosperm flowers from the Middle Eocene of southeastern North America include a variety of morphological types. The first of these specimens to be studied extensively, a catkin, has yielded a great deal of structural information. Floral morphology, pollen morphology, and the nature of the peltate scales suggest that this
W L, Crepet, D L, Dilcher, F W, Potter
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MAJOR CLADES OF THE ANGIOSPERMS
Cladistics, 1985Abstract— Our knowledge of fundamental angiosperm interrelationships is still very incomplete. The absence of a narrowly circumscribed gymnosperm outgroup, ideally the sister group, makes character evaluation, necessary for a cladistic analysis, difficult.
Rolf, Dahlgren, Kåre, Bremer
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The ecophysiology of early angiosperms
Plant, Cell & Environment, 2007ABSTRACTAngiosperms first appeared during the Early Cretaceous, and within 30 million years they reigned over many floras worldwide. Associated with this rise to prominence, angiosperms produced a spectrum of reproductive and vegetative innovations, which produced a cascade of ecological consequences that altered the ecology and biogeochemistry of the ...
Taylor S, Feild, Nan Crystal, Arens
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Polyploidy in Angiosperms: Dicotyledons
1980As summarized by Goldblatt (1) in the previous article, “Polyploidy in angiosperms: monocotyledons,” recent estimates of polyploid frequency among angiosperms vary from 30–35% to 47%. The highest value is based on the postulation that haploid numbers in excess of n=13 would be mainly polyploid and those with n=13 or less would be predominantly diploid (
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Photosynthesis: Rewiring an angiosperm
Nature Plants, 2016Flavodiiron proteins help to protect cyanobacteria from excess light through the dissipation of excess electrons. Introducing moss flavodiiron proteins into Arabidopsis raises its resilience to fluctuating light, illustrating the potential for augmenting higher plants with photosynthetic components from lower plants, algae and cyanobacteria.
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Polyploidy in Angiosperms: Monocotyledons
1980Several different estimates of polyploid frequency in angio-sperms have been made, including G.L. Stebbins’ (1,2) figure, first published in 1950, of 30–35%, and suggestions by M.J.D. White in 1942 (3) of at least 40%, and by Grant in 1963 (4) of 47%. These figures represent different ways of calculating Polyploidy and different interpretations of the ...
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Early Angiosperm Flowers and Angiosperm Evolution
2015Boletim de Resumos XXIV Congresso Brasileiro de Paleontologia pp43Paleontoiogi em Destaque Edicao especial-Agosto ...
Friis, Else Marie +1 more
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