scholarly journals PastView: a user-friendly interface to explore evolutionary scenarios

2019 ◽  
Author(s):  
François Chevenet ◽  
Guillaume Castel ◽  
Emmanuelle Jousselin ◽  
Olivier Gascuel

AbstractBackgroundAncestral character states computed from the combination of phylogenetic trees with extrinsic traits are used to decipher evolutionary scenarios in various research fields such as phylogeography, epidemiology, and ecology. Despite the existence of powerful methods and software in ancestral character state inference, difficulties may arise when interpreting the outputs of such inferences. The growing complexity of data (trees, annotations), the diversity of optimization criteria for computing trees and ancestral character states, the combinatorial explosion of potential evolutionary scenarios if some ancestral characters states do not stand out clearly from others, requires the design of new methods that operate on tree topologies and extrinsic traits associations to ease the identification of evolutionary scenarios.ResultWe developed a tool, PastView, a user-friendly interface that includes numerical and graphical features to help users to import and/or compute ancestral character states and extract evolutionary scenario as a set of successive transitions of ancestral character states from the tree root to its leaves. PastView offers synthetic views such as transition maps and integrates comparative analysis methods to highlight agreements or discrepancies between methods of ancestral annotations inference.ConclusionThe main contribution of PastView is to assemble known numerical and graphical methods into a multi-maps graphical user interface dedicated to the computing, searching and viewing of evolutionary scenarios based on phylogenetic trees and ancestral character states. PastView is available publicly as a standalone software on www.pastview.org.


Author(s):  
Sergei Tarasov ◽  
Istvan Miko ◽  
Matthew Yoder ◽  
Josef Uyeda

Ancestral character state reconstruction has been long used to gain insight into the evolution of individual traits in organisms. However, organismal anatomies (= entire phenotypes) are not merely ensembles of individual traits, rather they are complex systems where traits interact with each other due to anatomical dependencies (when one trait depends on the presence of another trait) and developmental constraints. Comparative phylogenetics has been largely lacking a method for reconstructing the evolution of entire organismal anatomies or organismal body regions. Herein, we present a new approach named PARAMO (Phylogenetic Ancestral Reconstruction of Anatomy by Mapping Ontologies, Tarasov and Uyeda 2019) that takes into account anatomical dependencies and uses stochastic maps (i.e., phylogenetic trees with an instance of mapped evolutionary history of characters, Huelsenbeck et al. 2003) along with anatomy ontologies to reconstruct organismal anatomies. Our approach treats the entire phenotype or its component body regions as single complex characters and allows exploring and comparing phenotypic evolution at different levels of anatomical hierarchy. These complex characters are constructed by ontology-informed amalgamation of elementary characters (i.e., those coded in character matrix) using stochastic maps. In our approach, characters are linked with the terms from an anatomy ontology, which allows viewing them not just as an ensemble of character state tokens but as entities that have their own biological meaning provided by the ontology. This ontology-informed framework provides new opportunities for tracking phenotypic radiations and anatomical evolution of organisms, which we explore using a large dataset for the insect order Hymenoptera (sawflies, wasps, ants and bees).



<em>Abstract</em>.-We develop the view, based on life cycle differences and recently published sister group relationships, that the freshwater life cycle was the ancestral character state leading to anadromy among salmoniforms, whereas the marine life cycle was the ancestral character state leading to anadromy among osmeriforms. In contrast to most salmonid fishes, the reproductive migrations of smelts are generally characterized by brief excursions to spawn in freshwater, and larvae may spend no more than 24 h in freshwater before being transported to coastal marine or estuarine environments. We reconstructed the phylogeny of the suborder Osmeroidei to establish the phylogenetic relationships among anadromous, marine, and freshwater species of this taxon. We mapped these life cycles onto phylogenetic trees of osmeriforms and salmoniforms and applied character-reconstruction methodology based on simple parsimony and likelihood methodologies. A freshwater origin of salmonids was supported by our analyses, whereas either marine or anadromous life cycles characterized the evolution of osmeroids. The possibility that the evolution of anadromy in salmonids and osmeroids followed separate paths requires a reconsideration of some generalizations concerning anadromy. We hypothesize that anadromy in osmeroids may be first and foremost an adaptation to place embryos and the early larval stages in reproductive safe sites to maximize their survival. The evolution of exclusive freshwater species of osmeriforms has occurred via anadromy through the various processes associated with landlocking. Freshwater amphidromy in osmeroids is most likely a consequence of anadromy rather than a precursor and may be contingent upon the availability of food resources in freshwater. Finally, marine osmeroids have been derived from anadromous ancestors and are "safe-site" specialists, exploiting principally the upper intertidal zone for reproduction. We also suggest that such contrasting evolutionary pathways to anadromy may provide insight into the evolution of partial migration, observed uniquely in salmonids, and the nature and extent of population genetic structure found in the two groups of fishes.



Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Julia Koblitz ◽  
Sabine Will ◽  
S. Riemer ◽  
Thomas Ulas ◽  
Meina Neumann-Schaal ◽  
...  

Genome-scale metabolic models are of high interest in a number of different research fields. Flux balance analysis (FBA) and other mathematical methods allow the prediction of the steady-state behavior of metabolic networks under different environmental conditions. However, many existing applications for flux optimizations do not provide a metabolite-centric view on fluxes. Metano is a standalone, open-source toolbox for the analysis and refinement of metabolic models. While flux distributions in metabolic networks are predominantly analyzed from a reaction-centric point of view, the Metano methods of split-ratio analysis and metabolite flux minimization also allow a metabolite-centric view on flux distributions. In addition, we present MMTB (Metano Modeling Toolbox), a web-based toolbox for metabolic modeling including a user-friendly interface to Metano methods. MMTB assists during bottom-up construction of metabolic models by integrating reaction and enzymatic annotation data from different databases. Furthermore, MMTB is especially designed for non-experienced users by providing an intuitive interface to the most commonly used modeling methods and offering novel visualizations. Additionally, MMTB allows users to upload their models, which can in turn be explored and analyzed by the community. We introduce MMTB by two use cases, involving a published model of Corynebacterium glutamicum and a newly created model of Phaeobacter inhibens.



2019 ◽  
Vol 68 (5) ◽  
pp. 698-716 ◽  
Author(s):  
Sergei Tarasov

Abstract Modeling discrete phenotypic traits for either ancestral character state reconstruction or morphology-based phylogenetic inference suffers from ambiguities of character coding, homology assessment, dependencies, and selection of adequate models. These drawbacks occur because trait evolution is driven by two key processes—hierarchical and hidden—which are not accommodated simultaneously by the available phylogenetic methods. The hierarchical process refers to the dependencies between anatomical body parts, while the hidden process refers to the evolution of gene regulatory networks (GRNs) underlying trait development. Herein, I demonstrate that these processes can be efficiently modeled using structured Markov models (SMM) equipped with hidden states, which resolves the majority of the problems associated with discrete traits. Integration of SMM with anatomy ontologies can adequately incorporate the hierarchical dependencies, while the use of the hidden states accommodates hidden evolution of GRNs and substitution rate heterogeneity. I assess the new models using simulations and theoretical synthesis. The new approach solves the long-standing “tail color problem,” in which the trait is scored for species with tails of different colors or no tails. It also presents a previously unknown issue called the “two-scientist paradox,” in which the nature of coding the trait and the hidden processes driving the trait’s evolution are confounded; failing to account for the hidden process may result in a bias, which can be avoided by using hidden state models. All this provides a clear guideline for coding traits into characters. This article gives practical examples of using the new framework for phylogenetic inference and comparative analysis.





IMA Fungus ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Claudio G. Ametrano ◽  
Felix Grewe ◽  
Pedro W. Crous ◽  
Stephen B. Goodwin ◽  
Chen Liang ◽  
...  

Abstract Dothideomycetes is the most diverse fungal class in Ascomycota and includes species with a wide range of lifestyles. Previous multilocus studies have investigated the taxonomic and evolutionary relationships of these taxa but often failed to resolve early diverging nodes and frequently generated inconsistent placements of some clades. Here, we use a phylogenomic approach to resolve relationships in Dothideomycetes, focusing on two genera of melanized, extremotolerant rock-inhabiting fungi, Lichenothelia and Saxomyces, that have been suggested to be early diverging lineages. We assembled phylogenomic datasets from newly sequenced (4) and previously available genomes (238) of 242 taxa. We explored the influence of tree inference methods, supermatrix vs. coalescent-based species tree, and the impact of varying amounts of genomic data. Overall, our phylogenetic reconstructions provide consistent and well-supported topologies for Dothideomycetes, recovering Lichenothelia and Saxomyces among the earliest diverging lineages in the class. In addition, many of the major lineages within Dothideomycetes are recovered as monophyletic, and the phylogenomic approach implemented strongly supports their relationships. Ancestral character state reconstruction suggest that the rock-inhabiting lifestyle is ancestral within the class.



Author(s):  
Agustín J Elias-Costa ◽  
Julián Faivovich

Abstract Cascades and fast-flowing streams impose severe restrictions on acoustic communication, with loud broadband background noise hampering signal detection and recognition. In this context, diverse behavioural features, such as ultrasound production and visual displays, have arisen in the evolutionary history of torrent-dwelling amphibians. The importance of the vocal sac in multimodal communication is being increasingly recognized, and recently a new vocal sac visual display has been discovered: unilateral inflation of paired vocal sacs. In the diurnal stream-breeding Hylodidae from the Atlantic forest, where it was first described, this behaviour is likely to be enabled by a unique anatomical configuration of the vocal sacs. To assess whether other taxa share this exceptional structure, we surveyed torrent-dwelling species with paired vocal sacs across the anuran tree of life and examined the vocal sac anatomy of exemplar species across 18 families. We found striking anatomical convergence among hylodids and species of the distantly related basal ranid genera Staurois, Huia, Meristogenys and Amolops. Ancestral character state reconstruction identified three new synapomorphies for Ranidae. Furthermore, we surveyed the vocal sac configuration of other anuran species that perform visual displays and report observations on what appears to be unilateral inflation of paired vocal sacs, in Staurois guttatus – an extremely rare behaviour in anurans.



Paleobiology ◽  
2012 ◽  
Vol 38 (2) ◽  
pp. 292-307 ◽  
Author(s):  
Francine R. Abe ◽  
Bruce S. Lieberman

The fossil record provides an important source of data on adaptive radiations, and indeed some of the earliest theoretical insights on the nature of these radiations were made by paleontologists. Here we focus on the diverse DevonianMetacryphaeusgroup calmoniid trilobites, known from the Malvinokaffric Realm, which have been considered a classic example of an adaptive radiation preserved in the fossil record. We use a geometric morphometric analysis in conjunction with phylogenetic and biogeographic patterns and data on speciation rates. Using ancestral character state reconstruction during speciation events, we quantify patterns of morphological change in order to assess the role ecological and geographical factors may have played in mediating this radiation. We found no significant differences between the amount of morphological change that occurred during speciation events when ancestors and descendants were in the same area as opposed to when they occupied different areas. Further, the magnitude of morphological divergence did not change through time or with cladogenetic rank. These patterns, in conjunction with the fact that the radiation occurs in a geographically heterogeneous region subjected to repeated episodes of sea-level rise and fall, suggest that at the macroevolutionary scale this radiation may have been motivated more by phenomena that facilitated geographic isolation than by competition.



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