scholarly journals Compressing Streams of Phylogenetic Trees

2018 ◽  
Author(s):  
Axel Trefzer ◽  
Alexandros Stamatakis
Keyword(s):  
Phylogenetic Tree ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Branch Length ◽  
Distinct Species ◽  
Mcmc Methods ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Posterior Probability Distribution ◽  
Tree Compression

AbstractBayesian Markov-Chain Monte Carlo (MCMC) methods for phylogenetic tree inference, that is, inference of the evolutionary history of distinct species using their molecular sequence data, typically generate large sets of phylogenetic trees. The trees generated by the MCMC procedure are samples of the posterior probability distribution that MCMC methods approximate. Thus, they generate a stream of correlated binary trees that need to be stored. Here, we adapt state-of-the art algorithms for binary tree compression to phylogenetic tree data streams and extend them to also store the required meta-data. On a phylogenetic tree stream containing 1, 000 trees with 500 leaves including branch length values, we achieve a compression rate of 5.4 compared to the uncompressed tree files and of 1.8 compared to bzip2-compressed tree files. For compressing the same trees, but without branch length values, our compression method is approximately an order of magnitude better than bzip2. A prototype implementation is available at https://github.com/axeltref/tree-compression.git.

scholarly journals Bayesian Estimation of Past Population Dynamics in BEAST 1.10 Using the Skygrid Coalescent Model

2019 ◽  
Vol 36 (11) ◽  
pp. 2620-2628 ◽  
Author(s):  
Verity Hill ◽  
Guy Baele
Keyword(s):  
Population Dynamics ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Effective Population ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Coalescent Model ◽  
Molecular Clock Model ◽  
Past Population ◽  
Over Time

Abstract Inferring past population dynamics over time from heterochronous molecular sequence data is often achieved using the Bayesian Skygrid model, a nonparametric coalescent model that estimates the effective population size over time. Available in BEAST, a cross-platform program for Bayesian analysis of molecular sequences using Markov chain Monte Carlo, this coalescent model is often estimated in conjunction with a molecular clock model to produce time-stamped phylogenetic trees. We here provide a practical guide to using BEAST and its accompanying applications for the purpose of drawing inference under these models. We focus on best practices, potential pitfalls, and recommendations that can be generalized to other software packages for Bayesian inference. This protocol shows how to use TempEst, BEAUti, and BEAST 1.10 (http://beast.community/; last accessed July 29, 2019), LogCombiner as well as Tracer in a complete workflow.

Tidying up the genus Letharia: introducing L. lupina sp. nov. and a new circumscription for L. columbiana

2016 ◽  
Vol 48 (5) ◽  
pp. 423-439 ◽  
Author(s):  
Susanne ALTERMANN ◽  
Steven D. LEAVITT ◽  
Trevor GOWARD
Keyword(s):  
Sequence Data ◽  
Species Recognition ◽  
Distinct Species ◽  
Species Level ◽  
Molecular Sequence Data ◽  
Traditional Concept ◽  
Molecular Sequence ◽  
Multispecies Coalescent ◽  
Centre Of Diversity ◽  
Candidate Species

AbstractWestern North America is the global centre of diversity for Letharia, a distinctive and cryptically diverse genus of lichenized fungi belonging to the Parmeliaceae. The genus is characterized by a shrubby, fruticose habit and presence of vulpinic acid. Previous studies using multiple fungal nuclear loci revealed the existence of two distinct species-level lineages within the traditional concept of L. vulpina and four such lineages within L. columbiana. Here we use molecular sequence data in an attempt to settle long-standing taxonomic issues in the genus. Our results confirm the widespread existence within L. vulpina s. lat. of two distinct species-level groups, each forming a mutually exclusive partnership with a separate algal clade within Trebouxia jamesii s. lat. Accordingly, we formally describe the segregate species L. lupina sp. nov. Our results also support the evolutionary independence of four candidate species previously circumscribed from L. columbiana s. lat. One of these lineages, L. ‘gracilis’, has already received species recognition as L. gracilis, while a second, L. ‘lucida’, is epitypified here against L. columbiana s. str. Based on results from species delimitation analyses under the multispecies coalescent model, the two remaining lineages, L. ‘barbata’ and L. ‘rugosa’, also warrant formal taxonomic recognition; however, we refrain from describing these species pending additional studies of diagnostic characters, ecological preference, and distributions.

scholarly journals Using Avida to Test the Effects of Natural Selection on Phylogenetic Reconstruction Methods

2004 ◽  
Vol 10 (2) ◽  
pp. 157-166 ◽  
Author(s):  
George I. Hagstrom ◽  
Dehua H. Hang ◽  
Charles Ofria ◽  
Eric Torng
Keyword(s):  
Natural Selection ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Phylogenetic Reconstruction ◽  
Branch Points ◽  
Reconstruction Algorithms ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Reconstruction Methods

Phylogenetic trees group organisms by their ancestral relationships. There are a number of distinct algorithms used to reconstruct these trees from molecular sequence data, but different methods sometimes give conflicting results. Since there are few precisely known phylogenies, simulations are typically used to test the quality of reconstruction algorithms. These simulations randomly evolve strings of symbols to produce a tree, and then the algorithms are run with the tree leaves as inputs. Here we use Avida to test two widely used reconstruction methods, which gives us the chance to observe the effect of natural selection on tree reconstruction. We find that if the organisms undergo natural selection between branch points, the methods will be successful even on very large time scales. However, these algorithms often falter when selection is absent.

Was Gordon Robilliard right? Integrative systematics suggest that Dendronotus diversicolor (multicolor frond-aeolis) is a valid species

2016 ◽  
Vol 94 (11) ◽  
pp. 793-799 ◽  
Author(s):  
I. Ekimova ◽  
Á. Valdés ◽  
D. Schepetov ◽  
A. Chichvarkhin
Keyword(s):  
Sequence Data ◽  
Distinct Species ◽  
External Morphology ◽  
Morphological Data ◽  
Valid Species ◽  
Colour Pattern ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Wide Range ◽  
Integrative Systematics

Nudibranch molluscs of the genus Dendronotus Alder and Hancock, 1845 are widely distributed in the Northern Hemisphere. Taxonomic studies on the genus Dendronotus have been problematic due to high variability in the colour pattern of many species, as well as in the external morphology and anatomy. In the present paper, we studied specimens of Dendronotus from northern Pacific presumably belonging to the species Dendronotus albus MacFarland, 1966 (white frond-aeolis). Molecular and morphological data revealed the existence of two distinct species among the material examined: D. albus, which has a wide range from Kamchatka and the Kurile Islands (from where we report this species for the first time) to California in North America, and the pseudocryptic species Dendronotus diversicolor Robilliard, 1970 (multicolor frond-aeolis), which has been previously considered a junior synonym of D. albus. Dendronotus diversicolor occurs from California, USA, to British Columbia, Canada, in sympatry with D. albus. Dendronotus albus and D. diversicolor can be clearly distinguished by colour pattern, internal and external morphology, and molecular sequence data. Despite some similarities in radular and external morphology between D. albus and D. diversicolor, these two species are phylogenetically distant and belong to different clades within the genus Dendronotus, which suggests convergent evolution.

The status of Myriangiaceae (Dothideomycetes)

Phytotaxa ◽  
2014 ◽  
Vol 176 (1) ◽  
pp. 219 ◽  
Author(s):  
ASHA J. DISSANAYAKE ◽  
RUVISHIKA S. JAYAWARDENA ◽  
SARANYAPHAT BOONMEE ◽  
KASUN M. THAMBUGALA ◽  
QING TIAN ◽  
...  
Keyword(s):  
Sequence Data ◽  
Molecular Data ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
The Family ◽  
The Status ◽  
Sexual State ◽  
Morphological And Molecular Data ◽  
Asexual State ◽  
Molecular Characters

The family Myriangiaceae is relatively poorly known amongst the Dothideomycetes and includes genera which are saprobic, epiphytic and parasitic on the bark, leaves and branches of various plants. The family has not undergone any recent revision, however, molecular data has shown it to be a well-resolved family closely linked to Elsinoaceae in Myriangiales. Both morphological and molecular characters indicate that Elsinoaceae differs from Myriangiaceae. In Elsinoaceae, small numbers of asci form in locules in light coloured pseudostromata, which form typical scab-like blemishes on leaf or fruit surfaces. The coelomycetous, “Sphaceloma”-like asexual state of Elsinoaceae, form more frequently than the sexual state; conidiogenesis is phialidic and conidia are 1-celled and hyaline. In Myriangiaceae, locules with single asci are scattered in a superficial, coriaceous to sub-carbonaceous, black ascostromata and do not form scab-like blemishes. No asexual state is known. In this study, we revisit the family Myriangiaceae, and accept ten genera, providing descriptions and discussion on the generic types of Anhellia, Ascostratum, Butleria, Dictyocyclus, Diplotheca, Eurytheca, Hemimyriangium, Micularia, Myriangium and Zukaliopsis. The genera of Myriangiaceae are compared and contrasted. Myriangium duriaei is the type species of the family, while Diplotheca is similar and may possibly be congeneric. The placement of Anhellia in Myriangiaceae is supported by morphological and molecular data. Because of similarities with Myriangium, Ascostratum (A. insigne), Butleria (B. inaghatahani), Dictyocyclus (D. hydrangea), Eurytheca (E. trinitensis), Hemimyriangium (H. betulae), Micularia (M. merremiae) and Zukaliopsis (Z. amazonica) are placed in Myriangiaceae. Molecular sequence data from fresh collections is required to confirm the relationships and placement of the genera in this family.

Apertochrysa (Neuroptera: Chrysopidae): A heterogeneric phantom? 

Zootaxa ◽  
2017 ◽  
Vol 4238 (1) ◽  
pp. 58 ◽  
Author(s):  
ATSUSHI MOCHIZUKI ◽  
CHARLES S. HENRY ◽  
PETER DUELLI
Keyword(s):  
Type Species ◽  
Morphological Traits ◽  
New Genus ◽  
Sequence Data ◽  
New Combination ◽  
Wing Venation ◽  
Monophyletic Clade ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Group Relationships

The small lacewing genus Apertochrysa comprises species from Africa, Asia and Australia. All lack a tignum, but otherwise resemble distantly related genera. We show that Apertochrysa does not form a monophyletic clade, based on analyses of molecular sequence data and morphological traits such as the presence and shape of the male gonapsis, wing venation, and larval setae. Apertochrysa kichijoi forms a clade with Eremochrysa, Suarius and Chrysemosa, whereas A. albolineatoides belongs to a clade that includes Cunctochrysa. Apertochrysa albolineatoides should become a new combination as Cunctochrysa albolineatoides, while A. kichijoi will have to be transferred to a new genus. The Australian A. edwardsi, the African A. eurydera and the type species of the genus Apertochrysa, A. umbrosa, join the large Pseudomallada group. Relationships of A. umbrosa are less certain, because for it we could amplify only one of the three nuclear genes used in the overall analysis. However, in all morphological traits tested, that species strongly resembles A. edwardsi and A. eurydera and thus is very likely just another exceptional Pseudomallada lacking a tignum. The fate of the genus name Apertochrysa depends on additional molecular and morphological analyses of A. umbrosa. 

scholarly journals The primary divisions of life: a phylogenomic approach employing composition-heterogeneous methods

2009 ◽  
Vol 364 (1527) ◽  
pp. 2197-2207 ◽  
Author(s):  
Peter G. Foster ◽  
Cymon J. Cox ◽  
T. Martin Embley
Keyword(s):  
Sequence Data ◽  
Phylogenetic Signal ◽  
Amino Acid Sequences ◽  
Rate Variation ◽  
Molecular Sequence Data ◽  
Protein Coding ◽  
Molecular Sequence ◽  
Heterogeneous Models ◽  
Matrix Heterogeneity ◽  
Rna Genes

The three-domains tree, which depicts eukaryotes and archaebacteria as monophyletic sister groups, is the dominant model for early eukaryotic evolution. By contrast, the ‘eocyte hypothesis’, where eukaryotes are proposed to have originated from within the archaebacteria as sister to the Crenarchaeota (also called the eocytes), has been largely neglected in the literature. We have investigated support for these two competing hypotheses from molecular sequence data using methods that attempt to accommodate the across-site compositional heterogeneity and across-tree compositional and rate matrix heterogeneity that are manifest features of these data. When ribosomal RNA genes were analysed using standard methods that do not adequately model these kinds of heterogeneity, the three-domains tree was supported. However, this support was eroded or lost when composition-heterogeneous models were used, with concomitant increase in support for the eocyte tree for eukaryotic origins. Analysis of combined amino acid sequences from 41 protein-coding genes supported the eocyte tree, whether or not composition-heterogeneous models were used. The possible effects of substitutional saturation of our data were examined using simulation; these results suggested that saturation is delayed by among-site rate variation in the sequences, and that phylogenetic signal for ancient relationships is plausibly present in these data.

Revealing the endophytic mycoflora in tea (Camellia sinensis) leaves in Sri Lanka: the first comprehensive study

Phytotaxa ◽  
2021 ◽  
Vol 514 (3) ◽  
pp. 247-260
Author(s):  
KASUN THAMBUGALA ◽  
DINUSHANI DARANAGAMA ◽  
SAGARIKA KANNANGARA ◽  
THENUKA KODITUWAKKU
Keyword(s):  
Sri Lanka ◽  
Camellia Sinensis ◽  
Endophytic Fungi ◽  
Sequence Data ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Tea Leaves ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Rdna Sequence Data

Endophytic fungi are a diverse group of microorganisms that live asymptomatically in healthy tissues of host and they have been reported from all kinds of plant tissues such as leaves, stems, roots, flowers, and fruits. In this study, fungal endophytes associated with tea leaves (Camellia sinensis) were collected from Kandy, Kegalle, and Nuwara Eliya districts in Sri Lanka and were isolated, characterized, and identified. A total of twenty endophytic fungal isolates belonging to five genera were recovered and ITS-rDNA sequence data were used to identify them. All isolated endophytic fungal strains belong to the phylum Ascomycota and the majority of these isolates were identified as Colletotrichum species. Phyllosticta capitalensis was the most commonly found fungal endophyte in tea leaves and was recorded in all three districts where the samples were collected. This is the very first investigation on fungal endophytes associated with C. sinensis in Sri Lanka based on molecular sequence data. In addition, a comprehensive account of known endophytic fungi reported worldwide on Camellia sinensis is provided.

scholarly journals Noteworthy record of the Ethiopian genet, Genetta abyssinica, (Carnivora, Viverridae) from Djibouti informs its phylogenetic position within Genetta

Mammalia ◽  
2019 ◽  
Vol 83 (2) ◽  
pp. 180-189 ◽  
Author(s):  
Adam W. Ferguson ◽  
Houssein R. Roble ◽  
Molly M. McDonough
Keyword(s):  
Phylogenetic Relationships ◽  
Sequence Data ◽  
Alternative Hypothesis ◽  
Phylogenetic Analyses ◽  
Phylogenetic Position ◽  
Sister Relationship ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Molecular Phylogenetic ◽  
Relationship Of

AbstractThe molecular phylogeny of extant genets (Carnivora, Viverridae,Genetta) was generated using all species with the exception of the Ethiopian genetGenetta abyssinica. Herein, we provide the first molecular phylogenetic assessment ofG. abyssinicausing molecular sequence data from multiple mitochondrial genes generated from a recent record of this species from the Forêt du Day (the Day Forest) in Djibouti. This record represents the first verified museum specimen ofG. abyssinicacollected in over 60 years and the first specimen with a specific locality for the country of Djibouti. Multiple phylogenetic analyses revealed conflicting results as to the exact relationship ofG. abyssinicato otherGenettaspecies, providing statistical support for a sister relationship to all other extant genets for only a subset of mitochondrial analyses. Despite the inclusion of this species for the first time, phylogenetic relationships amongGenettaspecies remain unclear, with limited nodal support for many species. In addition to providing an alternative hypothesis of the phylogenetic relationships among extant genets, this recent record provides the first complete skeleton of this species to our knowledge and helps to shed light on the distribution and habitat use of this understudied African small carnivore.

scholarly journals Techniques for the verification of minimal phylogenetic trees illustrated with ten mammalian haemoglobin sequences

1980 ◽  
Vol 187 (1) ◽  
pp. 65-74 ◽  
Author(s):  
D Penny ◽  
M D Hendy ◽  
L R Foulds
Keyword(s):  
Amino Acid ◽  
Phylogenetic Tree ◽  
Protein Sequence ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Protein Sequences ◽  
Nucleotide Sequences ◽  
Amino Acid Sequences ◽  
Minimal Tree ◽  
Protein Sequence Data

We have recently reported a method to identify the shortest possible phylogenetic tree for a set of protein sequences [Foulds Hendy & Penny (1979) J. Mol. Evol. 13. 127–150; Foulds, Penny & Hendy (1979) J. Mol. Evol. 13, 151–166]. The present paper discusses issues that arise during the construction of minimal phylogenetic trees from protein-sequence data. The conversion of the data from amino acid sequences into nucleotide sequences is shown to be advantageous. A new variation of a method for constructing a minimal tree is presented. Our previous methods have involved first constructing a tree and then either proving that it is minimal or transforming it into a minimal tree. The approach presented in the present paper progressively builds up a tree, taxon by taxon. We illustrate this approach by using it to construct a minimal tree for ten mammalian haemoglobin alpha-chain sequences. Finally we define a measure of the complexity of the data and illustrate a method to derive a directed phylogenetic tree from the minimal tree.

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