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Ancestral state reconstruction

Sereina Rutschmann, Harald Detering, Sabrina Simon, David H Funk, Jean-Luc Gattolliat, Samantha J Hughes, Pedro M Raposeiro, Rob DeSalle, Michel Sartori, Michael T Monaghan
The study of processes driving diversification requires a fully sampled and well resolved phylogeny. Multilocus approaches to the study of recent diversification provide a powerful means to study the evolutionary process, but their application remains restricted because multiple unlinked loci with suitable variation for phylogenetic or coalescent analysis are not available for most non-model taxa. Here we identify novel, putative single-copy nuclear DNA (nDNA) phylogenetic markers to study the colonization and diversification of an aquatic insect species complex, Cloeon dipterum L...
October 11, 2016: Molecular Phylogenetics and Evolution
Julia A Clarke, Sankar Chatterjee, Zhiheng Li, Tobias Riede, Federico Agnolin, Franz Goller, Marcelo P Isasi, Daniel R Martinioni, Francisco J Mussel, Fernando E Novas
From complex songs to simple honks, birds produce sounds using a unique vocal organ called the syrinx. Located close to the heart at the tracheobronchial junction, vocal folds or membranes attached to modified mineralized rings vibrate to produce sound. Syringeal components were not thought to commonly enter the fossil record, and the few reported fossilized parts of the syrinx are geologically young (from the Pleistocene and Holocene (approximately 2.5 million years ago to the present)). The only known older syrinx is an Eocene specimen that was not described or illustrated...
October 12, 2016: Nature
Nicolas Chazot, Keith R Willmott, Fabien L Condamine, Donna Lisa de-Silva, André V L Freitas, Gerardo Lamas, Hélène Morlon, Carlos E Giraldo, Chris D Jiggins, Mathieu Joron, James Mallet, Sandra Uribe, Marianne Elias
Understanding why species richness peaks along the Andes is a fundamental question in the study of Neotropical biodiversity. Several biogeographic and diversification scenarios have been proposed in the literature, but there is confusion about the processes underlying each scenario, and assessing their relative contribution is not straightforward. Here, we propose to refine these scenarios into a framework which evaluates four evolutionary mechanisms: higher speciation rate in the Andes, lower extinction rates in the Andes, older colonization times and higher colonization rates of the Andes from adjacent areas...
October 8, 2016: Molecular Ecology
Cheng-Hsiu Tsai, Naoki Kohno
Living baleen whales (Mysticeti) include the world's largest animals to have ever lived-blue whales (Balaenoptera musculus) can reach more than 30 m. However, the gigantism in baleen whales remains little explored. Here, we compiled all published stem mysticetes from the Eocene and Oligocene and then mapped the estimated body size onto different phylogenies that suggest distinct evolutionary histories of baleen whales. By assembling all known stem baleen whales, we present three novel findings in early mysticete evolution...
December 2016: Die Naturwissenschaften
Livia Donaire, Israel Pagán, María A Ayllón
The molecular characterization of a novel negative single-stranded RNA virus infecting the plant pathogenic fungus Botrytis cinerea is reported here. Comparison of the sequence of Botrytis cinerea negative-stranded RNA virus 1 (BcNSRV-1) showed a strong identity with RNA dependent RNA polymerases (RdRps) of plant pathogenic emaraviruses and tospoviruses. We have also found all the molecular signatures present in the RdRp of the genus Emaravirus and in other genera of family Bunyaviridae: the conserved TPD triplet and RY dinucleotide, the three basic residues in premotif A and the conserved motifs A, B, C, D, and E...
September 26, 2016: Virology
Martín O Pereyra, Molly C Womack, J Sebastián Barrionuevo, Boris L Blotto, Diego Baldo, Mariane Targino, Jhon Jairo Ospina-Sarria, Juan M Guayasamin, Luis A Coloma, Kim L Hoke, Taran Grant, Julián Faivovich
Most anurans possess a tympanic middle ear (TME) that transmits sound waves to the inner ear; however, numerous species lack some or all TME components. To understand the evolution of these structures, we undertook a comprehensive assessment of their occurrence across anurans and performed ancestral character state reconstructions. Our analysis indicates that the TME was completely lost at least 38 independent times in Anura. The inferred evolutionary history of the TME is exceptionally complex in true toads (Bufonidae), where it was lost in the most recent common ancestor, preceding a radiation of >150 earless species...
September 28, 2016: Scientific Reports
Josef C Uyeda, Luke J Harmon, Carrine E Blank
Cyanobacteria have exerted a profound influence on the progressive oxygenation of Earth. As a complementary approach to examining the geologic record-phylogenomic and trait evolutionary analyses of extant species can lead to new insights. We constructed new phylogenomic trees and analyzed phenotypic trait data using novel phylogenetic comparative methods. We elucidated the dynamics of trait evolution in Cyanobacteria over billion-year timescales, and provide evidence that major geologic events in early Earth's history have shaped-and been shaped by-evolution in Cyanobacteria...
2016: PloS One
Xuzhen Wang, Xiaoni Gan, Junbing Li, Yiyu Chen, Shunping He
Origin and diversification of the Tibetan polyploid cyprinids (schizothoracins) may help us to explore relationships between diversification of the cyprinids and the Tibetan Plateau uplift. Cyprininae phylogeny was analyzed using mitochondrial and nuclear DNA sequences to trace origins of polyploidy and diversifications of schizothoracins. Ancestral states reconstruction for ploidy levels indicated that the Cyprininae was diploid origin and the schizothoracin clades tetraploid origins. There were two diversification rate shifts along with diversification of the cyprinine fishes in response to the Tibetan uplift...
September 20, 2016: Science China. Life Sciences
Maria Fernanda Calió, Katherine B Lepis, José Rubens Pirani, Lena Struwe
The monophyletic and Neotropical tribe Helieae of the worldwide family Gentianaceae (Gentianales, Asterids, Angiospermae) is well known for its problematic generic classifications. An initial phylogenetic analysis of Helieae shed light onto the relationships between genera, and indicated that traditional generic limits did not correspond to monophyletic groups. In order to obtain a more thorough understanding of generic relationships within the group, we enhanced sampling within the so-called Symbolanthus clade and performed phylogenetic analyses from DNA sequences from one plastid region (matK) and two nuclear regions (ITS and 5S-NTS), plus 112 morphological characters, which were analyzed separately and in combination, using parsimony and Bayesian approaches...
September 15, 2016: Molecular Phylogenetics and Evolution
Bijendra Khadka, Mobolaji Adeolu, Robert E Blankenship, Radhey S Gupta
The evolution and diversification of different types of photosynthetic reaction centers (RCs) remains an important unresolved problem. We report here novel sequence features of the core proteins from Type I RCs (RC-I) and Type II RCs (RC-II) whose analyses provide important insights into the evolution of the RCs. The sequence alignments of the RC-I core proteins contain two conserved inserts or deletions (indels), a 3 amino acid (aa) indel that is uniquely found in all RC-I homologs from Cyanobacteria (both PsaA and PsaB) and a 1 aa indel that is specifically shared by the Chlorobi and Acidobacteria homologs...
September 16, 2016: Photosynthesis Research
Bradley C Allf, Paul A P Durst, David W Pfennig
Environmentally induced behavior (behavioral plasticity) has long been hypothesized to promote the origins of novel morphological traits, but this idea remains controversial. One context in which this hypothesis can be evaluated is animal communication, where behavior and morphology are often linked. Here, we examined the evolution of one of nature's most spectacular communication signals: the rattlesnake rattle. We specifically evaluated whether rattlesnake rattling behavior-and, hence, the rattle-originated from a simple behavior: vibrating the tail when threatened...
October 2016: American Naturalist
Jamie McCann, Gerald M Schneeweiss, Tod F Stuessy, Jose L Villaseñor, Hanna Weiss-Schneeweiss
Chromosome number change (polyploidy and dysploidy) plays an important role in plant diversification and speciation. Investigating chromosome number evolution commonly entails ancestral state reconstruction performed within a phylogenetic framework, which is, however, prone to uncertainty, whose effects on evolutionary inferences are insufficiently understood. Using the chromosomally diverse plant genus Melampodium (Asteraceae) as model group, we assess the impact of reconstruction method (maximum parsimony, maximum likelihood, Bayesian methods), branch length model (phylograms versus chronograms) and phylogenetic uncertainty (topological and branch length uncertainty) on the inference of chromosome number evolution...
2016: PloS One
Thanh-Lan Gluckman, Nicholas I Mundy
BACKGROUND: Avian plumage is ideal for investigating phenotypic convergence because of repeated evolution of the same within-feather patterns. In birds, there are three major types of regular patterns within feathers: scales, bars and spots. Existing models of within-feather pattern development suggest that scales have the simplest developmental mechanism, bars require more stringent regulation than scales, and spots have the strictest developmental parameters. We hypothesized that increasing stringency in the mechanism of pattern formation predicts the evolutionary trajectory of patterns, and hence scales should evolve first, followed by bars and finally spots...
2016: BMC Evolutionary Biology
Mats Töpel, Alexander Zizka, Maria Fernanda Calió, Ruud Scharn, Daniele Silvestro, Alexandre Antonelli
Understanding the patterns and processes underlying the uneven distribution of biodiversity across space constitutes a major scientific challenge in systematic biology and biogeography, which largely relies on effectively mapping and making sense of rapidly increasing species occurrence data. There is thus an urgent need for making the process of coding species into spatial units faster, automated, transparent, and reproducible. Here we present SpeciesGeoCoder, an open-source software package written in Python and R, that allows for easy coding of species into user-defined operational units...
August 2, 2016: Systematic Biology
Mark N Puttick
Ancestral state reconstruction of discrete character traits is often vital when attempting to understand the origins and homology of traits in living species. The addition of fossils has been shown to alter our understanding of trait evolution in extant taxa, but researchers may avoid using fossils alongside extant species if only few are known, or if the designation of the trait of interest is uncertain. Here, I investigate the impacts of fossils and incorrectly coded fossils in the ancestral state reconstruction of discrete morphological characters under a likelihood model...
August 2016: Biology Letters
Clifton D McKee, David T S Hayman, Michael Y Kosoy, Colleen T Webb
The influence of factors contributing to parasite diversity in individual hosts and communities are increasingly studied, but there has been less focus on the dominant processes leading to parasite diversification. Using bartonella infections in bats as a model system, we explored the influence of three processes that can contribute to bartonella diversification and lineage formation: (1) spatial correlation in the invasion and transmission of bartonella among bats (phylogeography); (2) divergent adaptation of bartonellae to bat hosts and arthropod vectors; and (3) evolutionary codivergence between bats and bartonellae...
October 2016: Infection, Genetics and Evolution
Maxi Polihronakis Richmond, Jane Park, Charles S Henry
Genitalia diversity in insects continues to fuel investigation of the function and evolution of these dynamic structures. While most studies have focused on variation in male genitalia, an increasing number of studies on female genitalia have uncovered comparable diversity among females, but often at a much finer morphological scale. In this study, we analyze the function and evolution of male and female genitalia in Phyllophaga scarab beetles, a group in which both sexes exhibit genitalic diversity. To document the interaction of male and female structures during mating, we dissected flash-frozen mating pairs from three Phyllophaga species and investigated fine scale morphology using SEM...
July 30, 2016: Journal of Evolutionary Biology
Doug M Boyer, E Christopher Kirk, Mary T Silcox, Gregg F Gunnell, Christopher C Gilbert, Gabriel S Yapuncich, Kari L Allen, Emma Welch, Jonathan I Bloch, Lauren A Gonzales, Richard F Kay, Erik R Seiffert
Primate species typically differ from other mammals in having bony canals that enclose the branches of the internal carotid artery (ICA) as they pass through the middle ear. The presence and relative size of these canals varies among major primate clades. As a result, differences in the anatomy of the canals for the promontorial and stapedial branches of the ICA have been cited as evidence of either haplorhine or strepsirrhine affinities among otherwise enigmatic early fossil euprimates. Here we use micro X-ray computed tomography to compile the largest quantitative dataset on ICA canal sizes...
August 2016: Journal of Human Evolution
Courtney C Stepien, Catherine A Pfister, J Timothy Wootton
Understanding functional trait distributions among organisms can inform impacts on and responses to environmental change. In marine systems, only 1% of dissolved inorganic carbon in seawater exists as CO2. Thus the majority of marine macrophytes not only passively access CO2 for photosynthesis, but also actively transport CO2 and the more common bicarbonate (HCO3-, 92% of seawater dissolved inorganic carbon) into their cells. Because species with these carbon concentrating mechanisms (CCMs) are non-randomly distributed in ecosystems, we ask whether there is a phylogenetic pattern to the distribution of CCMs among algal species...
2016: PloS One
M Azim Ansari, Xavier Didelot
The distribution of a phenotype on a phylogenetic tree is often a quantity of interest. Many phenotypes have imperfect heritability, so that a measurement of the phenotype for an individual can be thought of as a single realization from the phenotype distribution of that individual. If all individuals in a phylogeny had the same phenotype distribution, measured phenotypes would be randomly distributed on the tree leaves. This is, however, often not the case, implying that the phenotype distribution evolves over time...
September 2016: Genetics
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