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.

scholarly journals Hybridization and diversification are positively correlated across vascular plant families

2019 ◽  
Author(s):  
Nora Mitchell ◽  
Kenneth D. Whitney
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Causal Structure ◽  
Vascular Plant ◽  
Diversification Rates ◽  
Future Studies ◽  
Family Level ◽  
History Information ◽  
Plant Families ◽  
The Relationship

ABSTRACTHybridization has experimental and observational ties to evolutionary processes and outcomes such as adaptation, speciation, and radiation. Although it has been hypothesized that hybridization and diversification are correlated, this idea remains largely untested empirically. Here, we use a hybridization database on 195 plant families, life history information, and a time-calibrated family-level phylogeny to test for phylogenetically-corrected associations between hybridization and diversification rates, while also taking into account life-history traits that may be correlated with both processes. We show that diversification and hybridization are positively correlated using three different methods to estimate diversification rates and two different metrics of hybridization. Moreover, the relationship remains detectable when incorporating the correlations between diversification and two other life history characteristics, perenniality and woodiness. We further provide potential mechanisms for this association under three different scenarios: hybridization may drive diversification, diversification may drive hybridization, or both hybridization and diversification may jointly be driven by other factors. We suggest future studies to disentangle the causal structure.

scholarly journals The Rubisco small subunits in the green algal genus Chloromonas provide insights into evolutionary loss of the eukaryotic carbon-concentrating organelle, the pyrenoid

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ryo Matsuzaki ◽  
Shigekatsu Suzuki ◽  
Haruyo Yamaguchi ◽  
Masanobu Kawachi ◽  
Yu Kanesaki ◽  
...  
Keyword(s):  
Evolutionary Biology ◽  
De Novo ◽  
Small Subunit ◽  
Plant Evolution ◽  
Reaction Products ◽  
Photosynthetic Organisms ◽  
Green Algal ◽  
Interesting Study ◽  
Algal Genus ◽  
The Relationship

Abstract Background Pyrenoids are protein microcompartments composed mainly of Rubisco that are localized in the chloroplasts of many photosynthetic organisms. Pyrenoids contribute to the CO2-concentrating mechanism. This organelle has been lost many times during algal/plant evolution, including with the origin of land plants. The molecular basis of the evolutionary loss of pyrenoids is a major topic in evolutionary biology. Recently, it was hypothesized that pyrenoid formation is controlled by the hydrophobicity of the two helices on the surface of the Rubisco small subunit (RBCS), but the relationship between hydrophobicity and pyrenoid loss during the evolution of closely related algal/plant lineages has not been examined. Here, we focused on, the Reticulata group of the unicellular green algal genus Chloromonas, within which pyrenoids are present in some species, although they are absent in the closely related species. Results Based on de novo transcriptome analysis and Sanger sequencing of cloned reverse transcription-polymerase chain reaction products, rbcS sequences were determined from 11 strains of two pyrenoid-lacking and three pyrenoid-containing species of the Reticulata group. We found that the hydrophobicity of the RBCS helices was roughly correlated with the presence or absence of pyrenoids within the Reticulata group and that a decrease in the hydrophobicity of the RBCS helices may have primarily caused pyrenoid loss during the evolution of this group. Conclusions Although we suggest that the observed correlation may only exist for the Reticulata group, this is still an interesting study that provides novel insight into a potential mechanism determining initial evolutionary steps of gain and loss of the pyrenoid.

scholarly journals Trends in flower symmetry evolution revealed through phylogenetic and developmental genetic advances

2014 ◽  
Vol 369 (1648) ◽  
pp. 20130348 ◽  
Author(s):  
Lena C. Hileman
Keyword(s):  
Bilateral Symmetry ◽  
Radial Symmetry ◽  
Plant Evolution ◽  
Flowering Plant ◽  
Developmental Studies ◽  
Developmental Genetic ◽  
Evolutionary Transitions ◽  
Flower Symmetry ◽  
Molecular Phylogenetic ◽  
Developmental Programme

A striking aspect of flowering plant (angiosperm) diversity is variation in flower symmetry. From an ancestral form of radial symmetry (polysymmetry, actinomorphy), multiple evolutionary transitions have contributed to instances of non-radial forms, including bilateral symmetry (monosymmetry, zygomorphy) and asymmetry. Advances in flowering plant molecular phylogenetic research and studies of character evolution as well as detailed flower developmental genetic studies in a few model species (e.g. Antirrhinum majus , snapdragon) have provided a foundation for deep insights into flower symmetry evolution. From phylogenetic studies, we have a better understanding of where during flowering plant diversification transitions from radial to bilateral flower symmetry (and back to radial symmetry) have occurred. From developmental studies, we know that a genetic programme largely dependent on the functional action of the CYCLOIDEA gene is necessary for differentiation along the snapdragon dorsoventral flower axis. Bringing these two lines of inquiry together has provided surprising insights into both the parallel recruitment of a CYC -dependent developmental programme during independent transitions to bilateral flower symmetry, and the modifications to this programme in transitions back to radial flower symmetry, during flowering plant evolution.

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

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

scholarly journals Evolution of the Gekkotan Adhesive System: Does Digit Anatomy Point to One or More Origins?

2019 ◽  
Vol 59 (1) ◽  
pp. 131-147 ◽  
Author(s):  
Anthony P Russell ◽  
Tony Gamble
Keyword(s):  
Adhesive System ◽  
Adhesive Contact ◽  
Ancestral State ◽  
Evolutionary Transitions ◽  
Multiple Origins ◽  
Published Evidence ◽  
Enormous Variation ◽  
Phylogenetic Framework ◽  
Competing Hypotheses ◽  
Necessary And Sufficient

Abstract Recently-developed, molecularly-based phylogenies of geckos have provided the basis for reassessing the number of times adhesive toe-pads have arisen within the Gekkota. At present both a single origin and multiple origin hypotheses prevail, each of which has consequences that relate to explanations about digit form and evolutionary transitions underlying the enormous variation in adhesive toe pad structure among extant, limbed geckos (pygopods lack pertinent features). These competing hypotheses result from mapping the distribution of toe pads onto a phylogenetic framework employing the simple binary expedient of whether such toe pads are present or absent. It is evident, however, that adhesive toe pads are functional complexes that consist of a suite of integrated structural components that interact to bring about adhesive contact with the substratum and release from it. We evaluated the competing hypotheses about toe pad origins using 34 features associated with digit structure (drawn from the overall form of the digits; the presence and form of adhesive scansors; the proportions and structure of the phalanges; aspects of digital muscular and tendon morphology; presence and form of paraphalangeal elements; and the presence and form of substrate compliance-enhancing structures). We mapped these onto a well-supported phylogeny to reconstruct their evolution. Nineteen of these characters proved to be informative for all extant, limbed geckos, allowing us to assess which of them exhibit co-occurrence and/or clade-specificity. We found the absence of adhesive toe pads to be the ancestral state for the extant Gekkota as a whole, and our data to be consistent with independent origins of adhesive toe pads in the Diplodactylidae, Sphaerodactylidae, Phyllodactylidae, and Gekkonidae, with a strong likelihood of multiple origins in the latter three families. These findings are consistent with recently-published evidence of the presence of adhesively-competent digits in geckos generally regarded as lacking toe pads. Based upon morphology we identify other taxa at various locations within the gekkotan tree that are promising candidates for the expression of the early phases of adhesively-assisted locomotion. Investigation of functionally transitional forms will be valuable for enhancing our understanding of what is necessary and sufficient for the transition to adhesively-assisted locomotion, and for those whose objectives are to develop simulacra of the gekkotan adhesive system for biotechnological applications.

scholarly journals The early wasp plucks the flower: disparate extant diversity of sawfly superfamilies (Hymenoptera: ‘Symphyta’) may reflect asynchronous switching to angiosperm hosts

2019 ◽  
Vol 128 (1) ◽  
pp. 1-19
Author(s):  
Tommi Nyman ◽  
Renske E Onstein ◽  
Daniele Silvestro ◽  
Saskia Wutke ◽  
Andreas Taeger ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Insect Herbivore ◽  
Ancestral State ◽  
Asynchronous Switching ◽  
Time Intervals ◽  
Diversification Rates ◽  
Insect Order ◽  
Plant Associations ◽  
Diversity Dynamics ◽  
Herbivore Communities

AbstractThe insect order Hymenoptera originated during the Permian nearly 300 Mya. Ancestrally herbivorous hymenopteran lineages today make up the paraphyletic suborder ‘Symphyta’, which encompasses c. 8200 species with very diverse host-plant associations. We use phylogeny-based statistical analyses to explore the drivers of diversity dynamics within the ‘Symphyta’, with a particular focus on the hypothesis that diversification of herbivorous insects has been driven by the explosive radiation of angiosperms during and after the Cretaceous. Our ancestral-state estimates reveal that the first symphytans fed on gymnosperms, and that shifts onto angiosperms and pteridophytes – and back – have occurred at different time intervals in different groups. Trait-dependent analyses indicate that average net diversification rates do not differ between symphytan lineages feeding on angiosperms, gymnosperms or pteridophytes, but trait-independent models show that the highest diversification rates are found in a few angiosperm-feeding lineages that may have been favoured by the radiations of their host taxa during the Cenozoic. Intriguingly, lineages-through-time plots show signs of an early Cretaceous mass extinction, with a recovery starting first in angiosperm-associated clades. Hence, the oft-invoked assumption of herbivore diversification driven by the rise of flowering plants may overlook a Cretaceous global turnover in insect herbivore communities during the rapid displacement of gymnosperm- and pteridophyte-dominated floras by angiosperms.

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