Search results for "Systematics"
showing 10 items of 6702 documents
Allium kyrenium (Amaryllidaceae), a new species from Northern Cyprus.
2015
Allium kyrenium, a new species of Allium sect. Codonoprasum, is described and illustrated from northern Cyprus. It is a very circumscribed geophyte growing on the calcareous cliffs of the Kyrenia range. This diploid species, with a somatic chromosome number 2n = 16, shows close morphological relationships with A. stamineum, a species complex distributed in the eastern Mediterranean area. Its morphology, karyology, leaf anatomy, ecology, conservation status and taxonomical relationships with the allied species belonging to the A. stamineum group are examined.
Molecular phylogenetics and historical biogeography of the west-palearctic common toads (Bufo bufo species complex)
2012
In most pan-Eurasiatic species complexes, two phenomena have been traditionally considered key processes of their cladogenesis and biogeography. First, it is hypothesized that the origin and development of the Central Asian Deserts generated a biogeographic barrier that fragmented past continuous distributions in Eastern and Western domains. Second, Pleistocene glaciations have been proposed as the main process driving the regional diversification within each of these domains. The European common toad and its closest relatives provide an interesting opportunity to examine the relative contributions of these paleogeographic and paleoclimatic events to the phylogeny and biogeography of a wide…
The evolutionary history of the Arabidopsis arenosa complex: diverse tetraploids mask the Western Carpathian center of species and genetic diversity.
2012
The Arabidopsis arenosa complex is closely related to the model plant Arabidopsis thaliana. Species and subspecies in the complex are mainly biennial, predominantly outcrossing, herbaceous, and with a distribution range covering most parts of latitudes and the eastern reaches of Europe. In this study we present the first comprehensive evolutionary history of the A. arenosa species complex, covering its natural range, by using chromosome counts, nuclear AFLP data, and a maternally inherited marker from the chloroplast genome [trnL intron (trnL) and trnL/F intergenic spacer (trnL/F-IGS) of tRNA(Leu) and tRNA(Phe), respectively]. We unravel the broad-scale cytogeographic and phylogeographic pa…
Phylogeny and morphology of Anthracoidea pamiroalaica sp. nov. infecting the endemic sedge Carex koshewnikowii in the Pamir Alai Mts (Tajikistan)
2015
A novel Anthracoidea species, A. pamiroalaica on the endemic sedge Carex koshewnikowii, is described and illustrated from the Pamir Alai Mts in Tajikistan (Central Asia). The new species is phenotypically nearly identical with Anthracoidea sempervirentis, but clearly divergent genetically. Phylogenetic analyses based on LSU sequences showed affinity of Anthracoidea pamiroalaica to A. baldensis, A. rupestris, A. capillaris, and A. vankyi infecting host sedges in different Carex sections (Baldenses, Rupestres, Chlorostachyae, and Phaestoglochin, respectively), but not to A. misandrae, and A. sempervirentis, two sequenced species parasitic on host species from the section Aulocystis. This phyl…
Characterizing a hybrid zone between a cryptic species pair of freshwater snails.
2015
Characterizing hybrid zones and their dynamics is a central goal in evolutionary biology, but this is particularly challenging for morphologically cryptic species. The lack of conspicuous divergence between parental types means intermediate hybrid forms often go undetected. We aimed to detect and characterize a suspected hybrid zone between a pair of morphologically cryptic lineages of the freshwater snail, Radix. We sampled Radix from across a contact zone between two mitochondrial lineages (Radix balthica and an undescribed lineage termed 'MOTU3') and detected admixture between two nuclear genotype clusters, which were significantly but not categorically associated with the mitochondrial …
On the taxonomy of three sympatric sibling species of the Brachionus plicatilis (Rotifera) complex from Spain, with the description of B. ibericus n.…
2001
The accumulation of evidence during the last decade led to the splitting of the Brachionus plicatilis complex (Rotifera) into two morphologically recognizable species: B. plicatilis Muller and B. rotundiformis Tschugunoff, previously referred to as L- and S-type B. plicatilis (s.l.), respectively. However, recent population genetics and molecular studies have revealed that each of these taxa concern cryptic species complexes. In particular, in Torreblanca Marsh, a wetland on the Mediterranean coast of Spain, three genetically distinct groups in this rotifer complex have been shown to co-occur. Differences in genetic markers, ecological preferences, mixis responses, mating behaviour and no e…
Wing morphometrics as a possible tool for the diagnosis of the Ceratitis fasciventris, C. anonae, C. rosa complex (Diptera, Tephritidae)
2015
Abstract Previous attempts to resolve the Ceratitis FAR complex (Ceratitis fasciventris, Ceratitis anonae, Ceratitis rosa, Diptera, Tephritidae) showed contrasting results and revealed the occurrence of five microsatellite genotypic clusters (A, F1, F2, R1, R2). In this paper we explore the potential of wing morphometrics for the diagnosis of FAR morphospecies and genotypic clusters. We considered a set of 227 specimens previously morphologically identified and genotyped at 16 microsatellite loci. Seventeen wing landmarks and 6 wing band areas were used for morphometric analyses. Permutational multivariate analysis of variance detected significant differences both across morphospecies and g…
Phylogenetic analysis of cryptic speciation in the polychaetePygospio elegans
2012
Development in marine invertebrate species can take place through a variety of modes and larval forms, but within a species, developmental mode is typically uniform. Poecilogony refers to the presence of more than one mode of development within a single species. True poecilogony is rare, however, and in some cases, apparent poecilogony is actually the result of variation in development mode among recently diverged cryptic species. We used a phylogenetic approach to examine whether poecilogony in the marine polychaete worm, Pygospio elegans, is the result of cryptic speciation. Populations of worms identified as P. elegans express a variety of developmental modes including planktonic, broode…
Mitochondrial DNA variation and the evolutionary history of cryptic Gammarus fossarum types.
2000
The evolutionary history of the cryptic Gammarus fossarum species complex (Crustacea, Amphipoda) in Central Europe was approached by investigating the genetic variation in populations of a natural contact zone. Nucleotide sequence variation of a 395-bp segment of the mitochondrial 16S rRNA gene was compared to that of six nuclear allozyme loci. Three major mtDNA lineages were found, the eastern clade being consistent with the former allozyme type A. The two western clades (types B and C) were not distinguished previously. Strong sequence divergence and correlation with nuclear genetic isolation in syntopic populations, however, justifies the specific status of the three G. fossarum types. T…
Pre- and post-mating reproductive barriers drive divergence of five sympatric species of Naryciinae moths (Lepidoptera: Psychidae)
2014
The biological species concept suggests that species can be separated on the basis of reproductive isolation. However, because natural interbreeding capabilities are often unknown, differences in morphology are generally used to separate species. Alternatively, genetic dissimilarity is used to separate morphologically similar species. Many genetic markers, including the maternally inherited mitochondrial cytochrome oxidase I sequence, cannot show interbreeding and therefore species status of groups may remain unresolved. In species of the genera Dahlica and Siederia (Lepidoptera: Psychidae: Naryciinae) the lack of morphological distinction and unknown interbreeding has led to unclear and un…