Search results for "phylogenetics"
showing 10 items of 777 documents
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…
The role of hybridization in the evolution ofCousinias.str.(Asteraceae, Cardueae)
2009
Abstract Mehregan I. & Kadereit J. W.: The role of hybridization in the evolution of Cousinia s.str. (Asteraceae, Cardueae). — Willdenowia 39: 35–47. — Online ISSN 1868-6397; © 2009 BGBM Berlin-Dahlem. doi:10.3372/wi.39.39102 (available via http://dx.doi.org/) In order to assess the possible role of interspecific hybridization for the evolution of the high diversity of Cousinia subg. Cousinia (Cousinia s.str., c. 600 species), we examined the frequency of hybridization in this taxon. For this, hypothetical hybrid combinations published in the literature (28 putative hybrids and 11 intermediate forms) were critically examined. In addition, two hybrids were identified in the present study by …
Systematics and Phylogeny
2013
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…
Echinostomes: systematics and life cycles
2008
This chapter provides a review of the most significant literature in the last decade on the systematics and biology of echinostomes and echinostome-like digeneans. This review is primarily concerned with members of the genus Echinostoma, although members of other genera (Echinoparyphium, Echinochasmus, Himasthla, Hypoderaeum, Petasiger, Euparyphium, Stephanoprora, Isthmiophora, and Acanthoparyphium) and echinostome-related genera (Parorchis, Philophthalmus and Ribeiroia) are also considered. The literature on molecular systematics and morphometrics of these trematodes is reviewed. Specific mention is made of the life cycle patterns of echinostome and echinostome-like digeneans along with an…
Phylogeny of Veronica in the Southern and Northern Hemispheres based on plastid, nuclear ribosomal and nuclear low-copy DNA
2010
The cosmopolitan and ecologically diverse genus Veronica with approximately 450 species is the largest genus of the newly circumscribed Plantaginaceae. Previous analyses of Veronica DNA sequences were in stark contrast to traditional systematics. However, analyses did not allow many inferences regarding the relationship between major groups identified, hindering further analysis of diversification and evolutionary trends in the genus. To resolve the backbone relationships of Veronica, we added sequences from additional plastid DNA regions to existing data and analyzed matching data sets for 78 taxa and more than 5000 aligned characters from nuclear ribosomal DNA and plastid DNA regions. The…
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…