Topic
Fagales
About: Fagales is a research topic. Over the lifetime, 63 publications have been published within this topic receiving 2482 citations.
Papers published on a yearly basis
Papers
TL;DR: It is suggested that increased background research should be made at all stages of the calibration process to reduce errors wherever possible, from verifying the geochronological data on the fossils to critical reassessment of their phylogenetic position.
Abstract: Although temporal calibration is widely recognized as critical for obtaining accurate divergence-time estimates using molecular dating methods, few studies have evaluated the variation resulting from different calibration strategies. Depending on the information available, researchers have often used primary calibrations from the fossil record or secondary calibrations from previous molecular dating studies. In analyses of flowering plants, primary calibration data can be obtained from macro- and mesofossils (e.g., leaves, flowers, and fruits) or microfossils (e.g., pollen). Fossil data can vary substantially in accuracy and precision, presenting a difficult choice when selecting appropriate calibrations. Here, we test the impact of eight plausible calibration scenarios for Nothofagus (Nothofagaceae, Fagales), a plant genus with a particularly rich and well-studied fossil record. To do so, we reviewed the phylogenetic placement and geochronology of 38 fossil taxa of Nothofagus and other Fagales, and we identified minimum age constraints for up to 18 nodes of the phylogeny of Fagales. Molecular dating analyses were conducted for each scenario using maximum likelihood (RAxML + r8s) and Bayesian (BEAST) approaches on sequence data from six regions of the chloroplast and nuclear genomes. Using either ingroup or outgroup constraints, or both, led to similar age estimates, except near strongly influential calibration nodes. Using "early but risky" fossil constraints in addition to "safe but late" constraints, or using assumptions of vicariance instead of fossil constraints, led to older age estimates. In contrast, using secondary calibration points yielded drastically younger age estimates. This empirical study highlights the critical influence of calibration on molecular dating analyses. Even in a best-case situation, with many thoroughly vetted fossils available, substantial uncertainties can remain in the estimates of divergence times. For example, our estimates for the crown group age of Nothofagus varied from 13 to 113 Ma across our full range of calibration scenarios. We suggest that increased background research should be made at all stages of the calibration process to reduce errors wherever possible, from verifying the geochronological data on the fossils to critical reassessment of their phylogenetic position.
432 citations
TL;DR: Combined analysis provided some evidence for a relationship of Quercus to Lithocarpus and Chrysolepis, taxa with dichasially arranged pistillate flowers, where each flower is surrounded by cupular tissue, which indicates that a more broadly defined flower cupule may have a single origin.
Abstract: The family Fagaceae includes nine currently recognized genera and ca. 1000 species, making it one of the largest and most economically important groups within the order Fagales. In addition to wide variation in cupule and fruit morphology, polymorphism in pollination syndrome (wind vs. generalistic insect) also contributes to the uniqueness of the family. Phylogenetic relationships were examined using 179 accessions spanning the taxonomic breadth of the family, emphasizing tropical, subtropical, and relictual taxa. Nuclear ribosomal DNA sequences encoding the 5.8S rRNA gene and two flanking internal transcribed spacers (ITS) were used to evaluate phylogenetic hypotheses based on previous morphological cladistic analysis and intuitive schemes. Parsimony analyses rooted with Fagus supported two clades within the family, Trigonobalanus sensu lato and a large clade comprising Quercus and the castaneoid genera ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{b...
268 citations
Book•
15 Jan 1998
TL;DR: Fagales contains full checklists of important, mainly temperate genera such as Alnus, Betula, Corylaceae, Corylus, Castanea, Fagus, and Quercus, describing 531 species, their growth patterns, distribution and conservation status.
Abstract: Fagales contains full checklists of important, mainly temperate genera such as Alnus (alders), Betula (birches), Corylaceae (hornbeams), Corylus(hazels), Castanea (chestnuts), Fagus (northern beeches), Nothofagus (southern beeches), and Quercus (oaks), describing 531 species, their growth patterns, distribution and conservation status.
224 citations
TL;DR: The basal position of Nothofagus within the matK tree is consistent with the fossil record of "higher" hamamelids in which Noth ofagus pollen appears earlier than microfossils with affinities to other modern " Higher Hamamelididae.
Abstract: Phylogenetic relationships were examined within the ‘‘higher’’ Hamamelididae using 21 species representing eight families and related outgroups. Chloroplast DNA sequences encoding the matK gene ( ;1 kilobase) provided 258 informative nucleotide sites. Phylogenetic analysis of this variation produced one most parsimonious tree supporting three monophyletic groups. In this tree, Nothofagus was basal to a well supported clade of remaining ‘‘higher’’ hamamelids, in which Fagaceae, including Fagus, were sister to a clade of core ‘‘higher’’ hamamelids that share wind-pollination, bicarpellate flowers, granular pollen walls, and reduced pollen apertures. Within the core ‘‘higher’’ hamamelids three subclades were resolved, Myricaceae, (Casuarina-(Ticodendron-(Betulaceae))), and (Rhoiptelea-Juglandaceae). Each subclade was well supported but relationships among them were not. The basal position of Nothofagus within the matK tree is consistent with the fossil record of ‘‘higher’’ hamamelids in which Nothofagus pollen appears earlier than microfossils with affinities to other modern ‘‘higher’’ hamamelids. This placement supports the exclusion of Nothofagus from Fagaceae and suggests two hypotheses for the origin of the cupule. The cupule may be ancestral within ‘‘higher’’ hamamelids and subsequently lost in core members of the clade or there may have been two independent origins. It is suggested that the three clades (1) Nothofagaceae, (2) Fagaceae, and (3) Juglandaceae, Rhoiptelea, Myricaceae, Casuarina, Ticodendron, and Betulaceae be considered at the ordinal level and that traditional orders, such as Fagales sensu Cronquist (Fagaceae, Nothofagaceae, and Betulaceae) be abandoned. Comparative analyses of matK sequences with previously published rbcL sequences demonstrate that for the taxa considered here matK sequences produced trees with greater phylogenetic resolution and a higher consistency index.
156 citations
TL;DR: Parsimony analysis was used to develop phylogenetic hypotheses for Rosidae and other nonmagnoliid dicotyledons, especially Asteridae, and the problematic Columellia was placed among Asteridae as the sister group of Caprifoliaceae.
Abstract: Parsimony analysis was used to develop phylogenetic hypotheses for Rosidae and other nonmagnoliid dicotyledons, especially Asteridae Rosidae were placed among «lower» Hamamelidae as the sister group of Platanus and Hamamelidaceae «Higher» Hamamelidae (Fagales, juglandales, and Casuarinaceae), Dilleniidae, and Asteridae nest within a paraphyletic Rosidae With some expansion, the traditional Asteridae are monophyletic For example, the problematic Columellia was placed among Asteridae as the sister group of Caprifoliaceae Asteridae were placed as the sister group of Ericales among rosids circumscribed as Corniflorae in recent classifications of Dahlgren ()
137 citations
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| Year | Papers |
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| 2021 | 2 |
| 2020 | 4 |
| 2019 | 3 |
| 2018 | 2 |
| 2017 | 1 |
| 2016 | 4 |