Angiosperm origin and early stages of seed plant evolution deduced from rRNA sequence comparisons

1991 ◽  
Vol 32 (3) ◽  
pp. 253-261 ◽  
Author(s):  
A. V. Troitsky ◽  
Yu. F. Melekhovets ◽  
G. M. Rakhimova ◽  
V. K. Bobrova ◽  
K. M. Valiejo-Roman ◽  
...  
Keyword(s):  
Plant Evolution ◽  
Seed Plant ◽  
Rrna Sequence ◽  
Sequence Comparisons ◽  
Early Stages

Conductance in the wood of selected Carboniferous plants

Paleobiology ◽  
1986 ◽  
Vol 12 (3) ◽  
pp. 302-310 ◽  
Author(s):  
Michael A. Cichan
Keyword(s):  
Wood Anatomy ◽  
Growth Habit ◽  
Secondary Xylem ◽  
Middle Part ◽  
Specific Conductance ◽  
Plant Evolution ◽  
Seed Plant ◽  
Fossil Plants ◽  
Tracheary Elements ◽  
Conducting Tissue

Specific conductance was calculated for secondary xylem in seven Carboniferous stem taxa utilizing an equation derived from the Hagen-Poiseuille relation. Arborescent and lianoid representatives of major pteridophytic (Calamitaceae, Lepidodenraceae, Sphenophyllaceae) and gymnospermous (Cordaitaceae, Medullosaceae) groups were examined. In the calamite Arthropitys communis and the seed plant Cordaites (Cordaixylon sp. and Mesoxylon sp.), conductance corresponded approximately to the low end of the range for both extant conifers and angiosperms. A substantially higher conductance was determined for the wood of Arthropitys deltoides, conforming to the high end of the range for conifers and the low-middle part of the range for angiosperms. The highest conductance values were found in Sphenophyllum plurifoliatum, Medullosa noei, and Paralycopodites brevifolius and corresponded to the middle-high portion of the range for vessel-containing angiosperms. This outcome is particularly significant in light of the fact that tracheary elements in the fossils are imperforate. The results indicate that conductance in secondary xylem of some of the most ancient, woody groups was comparable to that in extant plants and that highly effective conducting tissue developed relatively early in plant evolution. Moreover, it is suggested that the general relationship between wood anatomy, growth habit, and ecology demonstrated for living plants can also be extended back in time to include fossil plants.

Late Permian seed-plant evolution

Science ◽  
2018 ◽  
Vol 362 (6421) ◽  
pp. 1372.17-1374
Author(s):  
Andrew M. Sugden
Keyword(s):  
Plant Evolution ◽  
Late Permian ◽  
Seed Plant

The use of functional analysis of the ribosome as a tool to determine archaebacterial phylogeny

1989 ◽  
Vol 35 (1) ◽  
pp. 141-147 ◽  
Author(s):  
R. Amils ◽  
L. Ramírez ◽  
J. L. Sanz ◽  
I. Marín ◽  
A. G. Pisabarro ◽  
...  
Keyword(s):  
Functional Analysis ◽  
16S Rrna ◽  
Phylogenetic Tree ◽  
Functional Information ◽  
Rrna Sequence ◽  
16S Rrna Sequence ◽  
Sequence Comparisons ◽  
Free System ◽  
Translation Apparatus ◽  
Evolutionary Clock

Forty different antibiotics with diverse kingdom and functional specificities were used to measure the functional characteristics of the archaebacterial translation apparatus. The resulting inhibitory curves, which are characteristic of the cell-free system analyzed, were transformed into quantitative values that were used to cluster the different archaebacteria analyzed. This cluster resembles the phylogenetic tree generated by 16S rRNA sequence comparisons. These results strongly suggest that functional analysis of an appropriate evolutionary clock, such as the ribosome, is of intrinsic phylogenetic value. More importantly, they indicate that the study of the nexus between genotypic and phenotypic (functional) information may shed considerable light on the evolution of the protein synthetic machinery.Key words: antibiotics, ribosomes, archaebacteria, phylogeny, functional analysis.

scholarly journals Experimental signal dissection and method sensitivity analyses reaffirm the potential of fossils and morphology in the resolution of the relationship of angiosperms and Gnetales

2017 ◽  
Author(s):  
Mario Coiro ◽  
Guillaume Chomicki ◽  
James A. Doyle
Keyword(s):  
Phylogenetic Signal ◽  
Plant Evolution ◽  
Sensitivity Analyses ◽  
Seed Plant ◽  
Long Branch Attraction ◽  
Model Based ◽  
Plant Phylogeny ◽  
History Of ◽  
Almost All ◽  
Relationship Of

AbstractThe placement of angiosperms and Gnetales in seed plant phylogeny remains one of the most enigmatic problems in plant evolution, with morphological analyses (which have usually included fossils) and molecular analyses pointing to very distinct topologies. Almost all morphology-based phylogenies group angiosperms with Gnetales and certain extinct seed plant lineages, while most molecular phylogenies link Gnetales with conifers. In this study, we investigate the phylogenetic signal present in published seed plant morphological datasets. We use parsimony, Bayesian inference, and maximum likelihood approaches, combined with a number of experiments with the data, to address the morphological-molecular conflict. First, we ask whether the lack of association of Gnetales with conifers in morphological analyses is due to an absence of signal or to the presence of competing signals, and second, we compare the performance of parsimony and model based approaches with morphological datasets. Our results imply that the grouping of Gnetales and angiosperms is largely the result of long branch attraction, consistent across a range of methodological approaches. Thus, there is a signal for the grouping of Gnetales with conifers in morphological matrices, but it was swamped by convergence between angiosperms and Gnetales, both situated on long branches. However, this effect becomes weaker in more recent analyses, as a result of addition and critical reassessment of characters. Even when a clade including angiosperms and Gnetales is still weakly supported by parsimony, model-based approaches favor a clade of Gnetales and conifers, presumably because they are more resistant to long branch attraction. Inclusion of fossil taxa weakens rather than strengthens support for a relationship of angiosperms and Gnetales. Our analyses finally reconcile morphology with molecules in favoring a relationship of Gnetales to conifers, and show that morphology may therefore be useful in reconstructing other aspects of the phylogenetic history of the seed plants.

scholarly journals Seed plant families with diverse mycorrhizal states have higher diversification rates

2019 ◽  
Author(s):  
María Isabel Mujica ◽  
Gustavo Burin ◽  
María Fernanda Pérez ◽  
Tiago Quental
Keyword(s):  
Soil Fungi ◽  
Plant Evolution ◽  
Ancestral State ◽  
Seed Plant ◽  
Plant Family ◽  
Symbiotic Interaction ◽  
Evolutionary Transitions ◽  
Diversification Rates ◽  
Plant Families ◽  
The Relationship

AbstractA crucial innovation in plant evolution was the association with soil fungi during land colonization. Today, this symbiotic interaction is present in most plants species and can be classified in four types: arbuscular (AM), Ecto (EM), Orchid (OM) and Ericoid Mycorrhiza (ER). Since the AM ancestral state, some plants lineages have switched partner (EM, OM and ER) or lost the association (no-association: NM). Evolutionary transitions to a novel mycorrhizal state (MS) might allow plant lineages to access new resources, enhancing diversification rates. However, some clades are not restricted to one MS, and this variability might promote diversification. In this study we address the relationship between MS and diversification rates of seed plant families. For this, we used the recently published FungalRoot database, which compiled data for 14,870 species and their mycorrhizal partners. We assigned a MS to each plant family, calculated the MS heterogeneity and estimated their diversification rates using the method-of-moments. Families with mixed MS had the highest diversification rates and there was a positive relationship between MS heterogeneity and diversification rates. These results support the hypothesis that MS lability promotes diversification and highlight the importance of the association with soil fungi for the diversification of plants.

Mesostigmatophyceae, a New Class of Streptophyte Green Algae Revealed by SSU rRNA Sequence Comparisons

Protist ◽  
1999 ◽  
Vol 150 (4) ◽  
pp. 399-417 ◽  
Author(s):  
Birger Marin ◽  
Michael Melkonian
Keyword(s):  
Green Algae ◽  
Ssu Rrna ◽  
Rrna Sequence ◽  
Sequence Comparisons ◽  
New Class

Are rRNA sequence comparisons the Rosetta stone of phylogenetics?

Cell ◽  
1986 ◽  
Vol 47 (5) ◽  
pp. 640 ◽  
Author(s):  
Lynn J. Rothschild ◽  
Mark A. Ragan ◽  
Annette W. Coleman ◽  
Peter Heywood ◽  
Susan A. Gerbi
Keyword(s):  
Rrna Sequence ◽  
Sequence Comparisons ◽  
Rosetta Stone
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