975 resultados para Cousinia, Systematics, Phylogeny
Resumo:
We inferred the phylogeny of 33 species of ticks from the subfamilies Rhipicephalinae and Hyalomminae from analyses of nuclear and mitochondrial DNA and morphology. We used nucleotide sequences from 12S rRNA, cytochrome c oxidase I, internal transcribed spacer 2 of the nuclear rRNA, and 18S rRNA. Nucleotide sequences and morphology were analyzed separately and together in a total-evidence analysis. Analyses of the five partitions together (3303 characters) gave the best-resolved and the best-supported hypothesis so far for the phylogeny of ticks in the Rhipicephalinae and Hyalomminae, despite the fact that some partitions did not have data for some taxa. However, most of the hidden conflict (lower support in the total-evidence analyses compared to that in the individual analyses) was found in those partitions that had taxa without data. The partitions with complete taxonomic sampling had more hidden support (higher support in the total-evidence analyses compared to that in the separate-partition analyses) than hidden conflict. Mapping of geographic origins of ticks onto our phylogeny indicates an African origin for the Rhipicephalinae sensu lato (i.e., including Hyalomma spp.), the Rhipicephalus-Boophilus lineage, the Dermacentor-Anocentor lineage, and the Rhipicephalus-Booophilus-Nosomma-Hyalomma-Rhipicentor lineage. The Nosomma-Hyalomma lineage appears to have evolved in Asia. Our total-evidence phylogeny indicates that (i) the genus Rhipicephalus is paraphyletic with respect to the genus Boophilus, (ii) the genus Dermacentor is paraphyletic with respect to the genus Anocentor, and (iii) some subgenera of the genera Hyalomma and Rhipicephalus are paraphyletic with respect to other subgenera in these genera. Study of the Rhipicephalinae and Hyalomminae over the last 7 years has shown that analyses of individual datasets (e.g., one gene or morphology) seldom resolve many phylogenetic relationships, but analyses of more than one dataset can generate well-resolved phylogenies for these ticks. (C) 2001 Academic Press.
Resumo:
Endeostigmata are early derivative acariform mites, fossils of which are known from the Devonian. Extant species bear numerous plesiomorphies, the most striking being remnant opisthosomal segmentation. Also, many are all-female parthenogens with broad geographical distributions. Many of the species reported in the present study may represent clones of ancient Gondwana species. Before the present study only a handful of endeostigmatans had been reported from Australia. A key to the families of Endeostigmata is provided in the present paper, along with a review of the Australian fauna of the families Alicorhagiidae (new record), Grandjeanicidae (new record), Oehserchestidae (new record), and Terpnacaridae. Terpnacarus gibbosus (Womersley) is redescribed. A report of the first records of the cosmopolitan parthenogens Alicorhagia usitata Theron et al., Alycosmesis palmata (Oudemans), Stigmalychus veretrum Theron et al., Terpnacarus carolinaensis Theron, and Oehserchestes arboriger (Theron) in Australia is provided, along with a description of the new species Grandjeanicus theroni (Grandjeanicidae). Terpnacarus variolus Shiba and T. glebulentus Theron are junior synonyms of T. gibbosus.
Resumo:
The Australian Neoseiulus Hughes and Typhlodromips de Leon (Acari: Phytoseiidae: Amblyseiinae) are revised and diagnosed, and three new related genera, Knopkirie, gen. nov., Olpiseius, gen. nov. and Pholaseius, gen. nov. are proposed and diagnosed. In Australia, Neoseiulus contains at least 44 species, 18 of which are newly described here, in six species-groups: the barkeri-group, womersleyi-group, cucumeris-group, cangaro-group, paloratus-group, and the paspalivorus-group. Typhlodromips contains six species, two previously described and four new species. Knopkirie contains four species, three of which are newly described here, in two species-groups: the petri-group and the banksiae-group. Olpiseius contains three species, one of which is newly described, all placed in the noncollyerae-group, and Pholaseius is monotypic, with one newly described species. Diagnoses and keys are provided for all Australian species in each of the above genera, as are keys to the amblyseiine genera currently recognised in Australia.
Resumo:
The taxonomic relationship between two toothed South African river crabs, Potamonautes warreni and P. unispinus, is unclear. The problem stems from the widespread variation in carapace dentition patterns amongst P. warreni individuals over its biogeographic range, where single toothed individuals may appear similar in carapace morphology to P. unispinus. Ten populations of P. warreni and 18 populations of P. unispinus were collected and the morphometric and genetic differentiation between the two taxa quantified. Patterns of morphometric and genetic variation were examined using multivariate statistics and protein gel electrophoresis, respectively. Principal component analyses of carapace characters showed that the two species are morphologically indistinguishable. However, discriminate functions analyses and additional statistical results corroborate the morphological distinction between the two taxa. Allozyme electrophoresis of 17 protein coding loci, indicated a close genetic similarity between the two species (I = 0.92). A fixed allelic difference at one locus (LT-2) and extensive genetic variability at another locus (PGM-1) indicate that two gene pools are present and that the two taxa are genetically isolated. Intraspecific genetic I values for both species were > 0.97 and indicated no apparent genetic structuring on a micro or macro-geographic scale. The variation in carapace dentition among P. warreni populations possesses no genetic basis and may possibly toe the product of ecogenesis. The value of dentition patterns in the systematics of river crabs is discussed. Dentition patterns among river crab species appear to be conserved and reliable as species specific diagnostic markers, but should ideally be used in combination with other morphological data sets and genetic evidence.
Resumo:
The composition of the Pyrgulidae and its relationships to other member families of the caenogastropod superfamily Rissooidea are examined after a consideration of new anatomical (including gross anatomy, sperm ultrastructure), conchological (including protoconch features), ecological, biogeographical and palaeontological data and a re-evaluation of existing literature. Pyrgulidae can be distinguished from hydrobiids unequivocally only with the aid of the radula. Sperm ultrastructural features suggest a very close relationship between the Pyrgulidae, the Hydrobiidae and the Bithyniidae (in fact no family-diagnostic sperm characters can be found to separate these three taxa). Based upon neontological and fossil evidence it is likely that pyrgulids represent a Miocene offshoot from a paratethyal hydrobiid lineage. Pyrgulids may also represent the stock from which the baicaliids arose, in which case the Pyrgulidae must be considered a paraphyletic group. The huge biogeographic gap between the Caspian Sea and Lake Baikal is to some extent bridged by the finding of a Neogene pyrgulid from the Altai Mountains. An alternative scenario for the origin of baicaliids is presented.
Resumo:
The walkeriana species-group of iridescent Euhesma bees is described with the following nine species considered new: E. allunga, E. banksia, E. bronzus, E. dongara, E. lobata, E. spinola, E. sybilae, E. viridescens and E. xana. Two new synonymies are proposed: E. mica (Cockerell) with E. neglectula (Cockerell), and E. halictoides (Rayment) with E. latissima (Cockerell). A key enables the separation of species, and distributions are mapped.