Search results for "Tree"
showing 10 items of 1841 documents
One is not enough: On the effects of reference genome for the mapping and subsequent analyses of short-reads.
2020
Mapping of high-throughput sequencing (HTS) reads to a single arbitrary reference genome is a frequently used approach in microbial genomics. However, the choice of a reference may represent a source of errors that may affect subsequent analyses such as the detection of single nucleotide polymorphisms (SNPs) and phylogenetic inference. In this work, we evaluated the effect of reference choice on short-read sequence data from five clinically and epidemiologically relevant bacteria (Klebsiella pneumoniae, Legionella pneumophila, Neisseria gonorrhoeae, Pseudomonas aeruginosa and Serratia marcescens). Publicly available whole-genome assemblies encompassing the genomic diversity of these species…
The Pleistocene subterranean volesTerricola (Rodentia) of Serbia and Montenegro
2001
A general morphometrical analysis of the M1 was conducted to identify the subterranean vole species found in Upper Pleistocene localities from Serbia and Montenegro, and to clarify the systematic position and the phylogenetic relationships between the different species in the Balkans. From the different localities studied, we can assign one population toMicrotus (Terricola) thomasi and the others to theM. (T.) subterraneus group. This study suggests thatM. (T.) grafi can be considered as a chronological sub-species ofM. (T.) subterraneus or as a different but phylogenetically very close species.
Evolutionary history of treecreeper vocalisations (Aves: Certhia)☆
2008
AbstractSince the vocalisations of passerine birds are in general a good means to separate taxa when external morphological differences are few, song and call recordings of 33 treecreeper (Certhia) taxa were sonagraphed and their parameters analysed. The vocalisations show low intra-individual and intra-population variation. Phylogenetic evolutionary units at the population level were delimited by time, frequency and syntax parameters by means of principal-component and discriminant analyses. Traits of territorial song were traced on a phylogenetic tree based on cytochrome b sequences, and a mean acoustic character difference was calculated. All presently recognised nine species could be di…
Reviewing lymnaeid vectors of fascioliasis by ribosomal DNA sequence analyses.
2005
AbstractSnails of the family Lymnaeidae are of great parasitological importance due to the numerous helminth species they transmit, mainly trematodiases (such as fascioliasis) of considerable medical and veterinary impact. The present knowledge of the genetics and host–parasite relationships of this gastropod group is far from adequate. Fascioliasis is caused by two species, Fasciola hepatica and F. gigantica, which, as in the case of other trematodes, show a marked snail host specificity. Many lymnaeid species involved in fascioliasis transmission still show a confused systematic-taxonomic status. The need for tools to distinguish and characterize species and populations of lymnaeids is ev…
Evolutionary transitions in broad tapeworms (Cestoda: Diphyllobothriidea) revealed by mitogenome and nuclear ribosomal operon phylogenetics
2021
Abstract Broad tapeworms (Diphyllobothriidea) are parasites whose adults are capable of infecting a wide range of freshwater, marine and terrestrial tetrapods including humans. Previous works examining the evolution of habitat and host use in this group have been hampered by the lack of a well-resolved phylogeny. In order to produce a robust phylogenetic framework for diphyllobothriideans, we sequenced the complete mitochondrial genome of 13 representatives, carefully chosen to cover the major clades, and two outgroup species representing the Spathebothriidea and Haplobothriidea. In addition, complementary data from the nuclear ribosomal operon was sequenced for 10 representative taxa. Mito…
On the origin and systematics of the northern African wood mouse (<i>Apodemus sylvaticus</i>) populations: a comparative study of mtDNA r…
2001
Conflicting hypotheses have been formulated regarding the origin of wood mouse (Apodemus sylvaticus) populations in northern Africa. In this study, the mtDNA restriction patterns of mice (n = 28) collected in Tunisia and Morocco are compared with those of representatives from southern Europe (n = 102). The neighbour-joining tree confirms the existence of the three lineages previously found in the Mediterranean area: western, TyrrhenianBalkan, and Sicilian. The western group is isolated from the two others, with bootstrap values of 89 and 95%. Northern African patterns are included in the western group. Their variability is low, the same pattern being shared by five Tunisian and all Morocca…
A new species of Tococladidae CARPENTER, 1966 from the Permian of France (Insecta: Archaeorthoptera)
2003
Abstract A new forewing venation pattern of the Tococladidae is proposed and the phylogenetic affinities of this family are discussed, based on Tococladus garrici nov. sp. This fossil comes from the Salagou Formation (Permian, Saxonian Group, Lodeve basin, France). The Tococladidae is assigned to the Archaeorthoptera BETHOUX and NEL, 2002 . The biostratigraphic implications of this discovery are briefly discussed, but it is still not possible to infer any definite conclusion about the age of this formation.
Ammonites phylogenetic analysis: state of the art and new prospects
2004
Abstract Two main types of data are available to resolve phylogenies using fossils data: (1) stratigraphic ordering of taxa, and (2) morphological characters. In most phylogenetic studies dealing with ammonites, authors have given priority to the stratigraphic distribution of taxa. This practice is classically justified by the fact that the ammonite fossil record is frequently outstandingly good. In practice, the level of integration of stratigraphic and morphologic information in a single analysis depends on the confidence that authors have in the quality of data. Besides, many evolutionary concepts, which could differ over time and between authors (e.g. anagenesis, cladogenesis, iterative…
The phylogenetic position and taxonomic status of Sterechinus bernasconiae Larrain, 1975 (Echinodermata, Echinoidea), an enigmatic Chilean sea urchin
2015
15 pages; International audience; Sterechinus is a very common echinoid genus in benthic communities of the Southern Ocean. It is widely distributed across the Antarctic and South Atlantic Oceans and has been the most frequently collected and intensively studied Antarctic echinoid. Despite the abundant literature devoted to Sterechinus, few studies have questioned the systematics of the genus. Sterechinus bernasconiae is the only species of Sterechinus reported from the Pacific Ocean and is only known from the few specimens of the original material. Based on new material collected during the oceanographic cruise INSPIRE on board the R/V Melville, the taxonomy and phylogenetic position of th…
Systematics and population genetics of the coldwater (Etheostoma ditrema) and watercress (Etheostoma nuchale) darters, with comments on the Gulf dart…
2005
Abstract Current taxonomy of the Etheostoma asprigene species group recognizes four species, two of which ( Etheostoma ditrema Ramsey and Suttkus and Etheostoma nuchale Howell and Caldwell) are restricted to isolated springs and spring-fed stream systems above the Fall Line of the Mobile Basin of Alabama, Georgia, and Tennessee. Previous studies of morphological and biochemical variation between disjunct populations of E. ditrema support the presence of multiple independent lineages. Unfortunately, the lack of phylogenetic methodology has made it impossible to distinguish historically differentiated non-sister taxa from currently intergrading sister lineages. The current study examines memb…