Diversification of Cynoglossinae genera (Cynoglosseae-Boraginaceae) in the western Irano-Turanian bioregion

The Irano-Turanian (I-T) bioregion harbours one of the Old world’s greatest repositories of botanical diversity; however, the diversification patterns and the phenotypic evolution of its flora are sorely understudied. The subtribe Cynoglossinae is characteristic of the western I-T bioregion, species–rich both in the desertic lowlands and the more mesic highlands of the Iranian plateau. About 70 species of Cynoglossinae are present in the Iranian plateau, 47 of which are endemic to the plateau.Herein, nuclear ITS and cpDNA rpl32-trnL and trnH–psbA sequences were used to investigate the molecular phylogeny, historical biogeography and ancestral character states of Cynoglossinae. Molecular dating and ancestral range reconstruction analyses indicated that the subtribe Cynoglossinae has initiated its diversification from the eastern part of the western I-T during the mid-Miocene, concomitantly with the uplift of the Pamir and Hindu Kush mountains. Moreover, from the Pliocene onwards the Afghan-India collision and extensive deformation of the Arabia-Eurasia convergence probably promoted allopatric speciation in Cynoglossinae via mostly vicariance events. Evolution of annuals with small nutlets from perennials with large nutlets was accompanied by mesic to desert habitats shifts. Herein, to explain distribution of Cynoglossinae in the western I-T, the congruence between cladogenetic, geological and palaeoclimatic events was investigated.

The molecular systematics and diversification of a taxonomically unstable group of Asian cicada tribes related to Cicadini Latreille, 1802 (Hemiptera : Cicadidae)

The cicadas (Hemiptera: Cicadidae) related to tribe Cicadini exhibit some of the most remarkable phenotypes in the family, with many genera possessing striking colour patterns and unusual morphological features. This largely Asian group of 13 tribes has proven challenging for cicada taxonomists, in part because of likely convergent evolution or losses of these phenotypes. We present the first focused molecular phylogeny of this clade, including ~60 described genera. The genetic dataset contains 839 ingroup-informative sites (out of 2575) from mitochondrial cytochromec oxidase subunitI, nuclear elongation factor-1α, and nuclear acetyltransferase. We use Bayesian and maximum likelihood trees to test recent changes in tribe- and subtribe-level classification, and we reconstruct ancestral character states for potentially convergent traits influencing tribe descriptions. We use fossil and molecular clock calibrations to estimate the temporal and geographic context of the radiation. The tribes Gaeanini, Leptopsaltriini, Platypleurini, Psithyristriini, and Tosenini appear polyphyletic and in need of revision, in part because of convergent evolution of opaque wings and multiple convergent gains or losses of abdominal tubercles. Kalabita Moulton, 1923 is transferred from Platypleurini to Leptopsaltriini. Vittagaeana gen. nov. is established for Vittagaeana paviei comb. nov. and Vittagaeana dives comb. nov., formerly in Tosena. Sinosenini syn. nov. is synonymised with Dundubiina. Ayuthiini trib. nov. is established with two new subtribes for Ayuthia Distant, 1919 and Distantalna Boulard, 2009, formerly in Tosenini. For the earliest split in the tree, one common ancestor appears to have been Indian + Asian in geographic distribution and the other Asian. We estimate that the radiation began in the middle Cenozoic Era, possibly as recently as the early Miocene. The recent and steady pattern of diversification suggests that refinement of tribe diagnoses will prove challenging. http://zoobank.org:urn:lsid:zoobank.org:pub:5A6C16F4-5269-453B-BA5C-B29C3394683A

A re-evaluation of the Chaetothyriales using criteria of comparative biology

Chaetothyriales is an ascomycetous order within Eurotiomycetes. The order is particularly known through the black yeasts and filamentous relatives that cause opportunistic infections in humans. All species in the order are consistently melanized. Ecology and habitats of species are highly diverse, and often rather extreme in terms of exposition and toxicity. Families are defined on the basis of evolutionary history, which is reconstructed by time of divergence and concepts of comparative biology using stochastical character mapping and a multi-rate Brownian motion model to reconstruct ecological ancestral character states. Ancestry is hypothesized to be with a rock-inhabiting life style. Ecological disparity increased significantly in late Jurassic, probably due to expansion of cytochromes followed by colonization of vacant ecospaces. Dramatic diversification took place subsequently, but at a low level of innovation resulting in strong niche conservatism for extant taxa. Families are ecologically different in degrees of specialization. One of the clades has adapted ant domatia, which are rich in hydrocarbons. In derived families, similar processes have enabled survival in domesticated environments rich in creosote and toxic hydrocarbons, and this ability might also explain the pronounced infectious ability of vertebrate hosts observed in these families. Conventional systems of morphological classification poorly correspond with recent phylogenetic data. Species are hypothesized to have low competitive ability against neighboring microbes, which interferes with their laboratory isolation on routine media. The dataset is unbalanced in that a large part of the extant biodiversity has not been analyzed by molecular methods, novel taxonomic entities being introduced at a regular pace. Our study comprises all available species sequenced to date for LSU and ITS, and a nomenclatural overview is provided. A limited number of species could not be assigned to any extant family.

Character evolution of modern fly-speck fungi and implications for interpreting thyriothecial fossils

PREMISE OF THE STUDYFossils show that fly-speck fungi have been reproducing with small, black thyriothecia on leaf surfaces for ∼250 million years. We analyze morphological characters of extant thyriothecial fungi to develop a phylogenetic framework for interpreting fossil taxa.METHODSWe placed 59 extant fly-speck fungi in a phylogeny of 320 Ascomycota using nuclear ribosomal large and small subunit sequences, including newly determined sequences from nine taxa. We reconstructed ancestral character states using BayesTraits and maximum likelihood after coding 11 morphological characters based on original observations and literature. We analyzed the relationships of three previously published Mesozoic fossils using parsimony and our morphological character matrix, constrained by the molecular phylogeny.KEY RESULTSThyriothecia evolved convergently in multiple lineages of superficial, leaf- inhabiting ascomycetes. The radiate and ostiolate scutellum organization is restricted to Dothideomycetes. Scutellum initiation by intercalary septation of a single hypha characterizes Asterinales and Asterotexiales, and initiation by coordinated growth of two or more adjacent hyphae characterizes Aulographaceae (order incertae sedis). Scutella in Microthyriales are initiated apically on a lateral hyphal branch. Patterns of hyphal branching in scutella contribute to distinguishing among orders. Parsimony resolves three fossil taxa as Dothideomycetes; one is further resolved as a member of a Microthyriales-Zeloasperisporiales clade within Dothideomycetes.CONCLUSIONSThis is the most comprehensive systematic study of thyriothecial fungi and their relatives to date. Parsimony analysis of the matrix of character states of modern taxa provides an objective basis for interpreting fossils, leading to insights into morphological evolution and geological ages of Dothideomycetes clades.

Macroevolutionary analysis of discrete traits with rate heterogeneity

Organismal traits show dramatic variation in phylogenetic patterns of origin and loss across the Tree of Life. Understanding the causes and consequences of this variation depends critically on accounting for heterogeneity in rates of trait evolution among lineages. Here, we describe a method for modeling among-lineage evolutionary rate heterogeneity in a trait with two discrete states. The method assumes that the present-day distribution of a binary trait is shaped by a mixture of stochastic processes in which the rate of evolution varies among lineages in a phylogeny. The number and location of rate changes, which we refer to as rate-shift events, are inferred automatically from the data. Simulations reveal that the method accurately reconstructs rates of trait evolution and ancestral character states even when simulated data violate model assumptions. We apply the method to an empirical dataset of mimetic coloration in snakes and find elevated rates of trait evolution in two clades of harmless snakes that are broadly sympatric with dangerously venomous New World coral snakes, recapitulating an earlier analysis of the same dataset. Although the method performed well on many simulated data sets, we caution that overall power for inferring heterogeneous dynamics of single binary traits is low.

Macroevolutionary analysis of discrete character evolution using parsimony-informed likelihood

Rates of character evolution in macroevolutionary datasets are typically estimated by maximizing the likelihood function of a continuous-time Markov chain (CTMC) model of character evolution over all possible histories of character state change, a technique known as maximum average likelihood. An alternative approach is to estimate ancestral character states independently of rates using parsimony and to then condition likelihood-based estimates of transition rates on the resulting ancestor-descendant reconstructions. We use maximum parsimony reconstructions of possible pathways of evolution to implement this alternative approach for single-character datasets simulated on empirical phylogenies using a two-state CTMC. We find that transition rates estimated using parsimonious ancestor-descendant reconstructions have lower mean squared error than transition rates estimated by maximum average likelihood. Although we use a binary state character for exposition, the approach remains valid for an arbitrary number of states. Finally, we show how this method can be used to rapidly and easily detect phylogenetic variation in tempo and mode of character evolution with two empirical examples from squamates. These results highlight the mutually informative roles of parsimony and likelihood when testing hypotheses of character evolution in macroevolution.

Genome size and endopolyploidy evolution across the moss phylogeny

Background and Aims Compared with other plant lineages, bryophytes have very small genomes with little variation across species, and high levels of endopolyploid nuclei. This study is the first analysis of moss genome evolution over a broad taxonomic sampling using phylogenetic comparative methods. We aim to determine whether genome size evolution is unidirectional as well as examine whether genome size and endopolyploidy are correlated in mosses. Methods Genome size and endoreduplication index (EI) estimates were newly generated using flow cytometry from moss samples collected in Canada. Phylogenetic relationships between moss species were reconstructed using GenBank sequence data and maximum likelihood methods. Additional 1C-values were compiled from the literature and genome size and EI were mapped onto the phylogeny to reconstruct ancestral character states, test for phylogenetic signal and perform phylogenetic independent contrasts. Key Results Genome size and EI were obtained for over 50 moss taxa. New genome size estimates are reported for 33 moss species and new EIs are reported for 20 species. In combination with data from the literature, genome sizes were mapped onto a phylogeny for 173 moss species with this analysis, indicating that genome size evolution in mosses does not appear to be unidirectional. Significant phylogenetic signal was detected for genome size when evaluated across the phylogeny, whereas phylogenetic signal was not detected for EI. Genome size and EI were not found to be significantly correlated when using phylogenetically corrected values. Conclusions Significant phylogenetic signal indicates closely related mosses have more similar genome sizes and EI values. This study supports that DNA content in mosses is defined by small genomes that are highly endopolyploid, suggesting strong selective pressure to maintain these features. Further research is needed to understand the functional significance of DNA content evolution in mosses.

PastView: a user-friendly interface to explore evolutionary scenarios

BackgroundAncestral 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.

Opsin genes of select treeshrews resolve ancestral character states within Scandentia

Treeshrews are small, squirrel-like mammals in the order Scandentia, which is nested together with Primates and Dermoptera in the superordinal group Euarchonta. They are often described as living fossils, and researchers have long turned to treeshrews as a model or ecological analogue for ancestral primates. A comparative study of colour vision-encoding genes within Scandentia found a derived amino acid substitution in the long-wavelength sensitive opsin gene ( OPN1LW ) of the Bornean smooth-tailed treeshrew ( Dendrogale melanura ). The opsin, by inference, is red-shifted by ca 6 nm with an inferred peak sensitivity of 561 nm. It is tempting to view this trait as a novel visual adaptation; however, the genetic and functional diversity of visual pigments in treeshrews is unresolved outside of Borneo. Here, we report gene sequences from the northern smooth-tailed treeshrew ( Dendrogale murina ) and the Mindanao treeshrew ( Tupaia everetti , the senior synonym of Urogale everetti ). We found that the opsin genes are under purifying selection and that D. murina shares the same substitution as its congener, a result that distinguishes Dendrogale from other treeshrews, including T. everetti. We discuss the implications of opsin functional variation in light of limited knowledge about the visual ecology of smooth-tailed treeshrews.

Linguistic homoplasy and phylogeny reconstruction. The cases of Lezgian and Tsezic languages (North Caucasus)

This paper deals with the problem of linguistic homoplasy (parallel or backward development), how it can be detected, what kinds of linguistic homoplasy can be distinguished and which varieties of the phenomenon are the most deleterious for the reconstruction of language phylogeny. It is proposed that language phylogeny reconstruction should consist of two main stages. Firstly, a strict consensus tree should be built on the basis of high-quality input data elaborated with the help of the main phylogenetic methods (such as Neighbor-joining, Bayesian MCMC, and Maximum parsimony), and ancestral character states, allowing us to reveal a certain number of homoplastic characters. Secondly, after the detected instances of homoplasy are eliminated from the input matrix, the consensus tree is to be compiled again. It is expected that after homoplastic optimization it will be possible to better resolve individual “problem clades”, and generally the homoplasy-optimized phylogeny should be more robust than the tree constructed initially. The proposed procedure is tested on the 110-item Swadesh wordlists of the Lezgian and Tsezic groups. The Lezgian and Tsezic results generally support theoretical expectations. The MLN (minimal lateral network) method, currently implemented in the LingPy software, is a helpful tool for the detection of linguistic homoplasy.