800 resultados para cladistic biogeography
Resumo:
Phylogenetic studies of the genus Macropodinium were conducted using two methods; phenetics and cladistics. The phenetic study of morphometrics suggested that the genus could be divided into 3 groups attributable mostly to cell size and shape. The cladistic study also split the genus into 3 groups related to cell size but groups were further distinguished by patterns of ornamentation. Reconciliation of both approaches revealed considerable congruence, however, it also suggested the existence of convergences in the phenetic study and a lack of resolution in the cladistic study. The morphological diversity of Macropodinium is probably due to evolutionary trends such as increasing body size, allometry and polymerisation of structures. None of these trends, however, was uniformly directional and differential effects were observed in different regions of the phylogenetic tree. Comparison of the phylogeny of Macropodinium to a consensus phylogeny of the macropodids revealed limited incongruence between the 2 trees. The ciliate groups could be related to 2 host groups; the wallaby genera and the kangaroo and wallaroo subgenera. The association with these host groups may be the result of phyletic codescent, ecological resource tracking or a combination of both. Further studies of both host and ciliate phylogeny are necessary to resolve these effects.
Resumo:
Euastacus crayfish are endemic to freshwater ecosystems of the eastern coast of Australia. While recent evolutionary studies have focused on a few of these species, here we provide a comprehensive phylogenetic estimate of relationships among the species within the genus. We sequenced three mitochondrial gene regions (COI, 16S, and 12S) and one nuclear region (28S) from 40 species of the genus Euastacus, as well as one undescribed species. Using these data, we estimated the phylogenetic relationships within the genus using maximum-likelihood, parsimony, and Bayesian Markov Chain Monte Carlo analyses. Using Bayes factors to test different model hypotheses, we found that the best phylogeny supports monophyletic groupings of all but two recognized species and suggests a widespread ancestor that diverged by vicariance. We also show that Eitastacus and Astacopsis are most likely monophyletic sister genera. We use the resulting phylogeny as a framework to test biogeographic hypotheses relating to the diversification of the genus. (c) 2005 Elsevier Inc. All rights reserved.
Resumo:
The Quadrifoliovariinae is revised and three new species of Quadrifoliovarium Yamaguit, 1965 from acanthurid fishes of the genus Naso from waters of the Indo-Pacific are described: Q, maceria n. sp. from N. tonganus, N. annulatus, N. fageni and N. brevirostris; Q. simplex n. sp. from N. tonganus and N. quannulatus; and Q. quattuordecim n. sp. from N. tonganus. Amendments are made to the characterisation of the Quadrifoliovariinae, Quadrifoliovarium, Bilacinia Manter, 1969 and Unilacinia Manter, 1969 in light of observations on type and new material. A molecular phylogeny based on ITS2 and 28S regions of the ribosomal DNA is proposed. The phylogeny suggests that U. asymmetrica is the most basal taxon and Q. simplex n. sp. and Q. quattuordecim n. sp. the most derived. Evolution of morphological traits within the Quadrifoliovariinae are discussed in light of the molecular phylogeny. Molecular sequences of the ITS2 rDNA were identical between specimens of Q. pritchardae collected off Exmouth (Indian Ocean), Heron Island and Lizard Island (Western Pacific) and Moorea (far Eastern Indo-Pacific), indicating a broad Indo-Pacific distribution. All members of the subfamily are recorded only from the acanthurid genus Naso, with the exception of B. lobatum (Yamaguti, 1970), which has been recorded from a pomacanthid. The restricted host range of the group is discussed in the light of the phylogeny of the host genus Naso.
Resumo:
Isla del Coco (Cocos Island) is a small volcanic island located in the Pacific 500 km west of Costa Rica. Three collecting trips to Isla del Coco, in addition to herbarium research, were completed in order to assess the floristic diversity of the island. The current flora of Isla del Coco contains 262 plant species of which 37 (19.4%) are endemic. This study reports 58 species as new to the island. Seventy-one species (27.1%) were identified as introduced by humans. In addition, five potentially invasive plant species are identified. Seven vegetation types are identified on the island: bayshore, coastal cliff, riparian, low elevation humid forest, high elevation cloud forest, landslide and islet. ^ The biogeographic affinities of the native and endemic species are with Central America/northern South America and to a lesser extent, the Caribbean. Endemic species in the genus Epidendrum were investigated to determine whether an insular radiation event had produced two species found on Isla del Coco. Phylogenetic analysis of the internal transcribed spacer (ITS) of nuclear ribosomal DNA was not able to disprove that the endemic species in this genus are not sister species. Molecular biogeographic analyses of ITS sequence data determined that the Isla del Coco endemic species in the genera Epidendrum, Pilea and Psychotria are most closely related to Central American/northern South American taxa. No biogeographical links were found between the floras of Isla del Coco and the Galápagos Islands. ^ The native and endemic plant diversity of Isla del Coco is threatened with habitat degradation by introduced pigs and deer, and to a lesser extent, by exotic plant species. The IUCN Red List and RAREplants criteria were used to assess the extinction threat for the 37 endemic plant taxa found on the island. All of the endemic species are considered threatened with extinction at the Critically Endangered (CR) by the IUCN criteria or either CR or Endangered (EN) using RAREplants methodology. ^
Resumo:
The Caribbean Island Biodiversity Hotspot is the largest insular system of the New World and a priority for biodiversity conservation worldwide. The tribe Adeliae (Euphorbiaceae) has over 35 species endemic to this hotspot, representing one of the most extraordinary cases of speciation in the West Indies, involving taxa from Cuba, Hispaniola, Jamaica, and the Bahamas. These species form a monophyletic group and traditionally have been accommodated in two endemic genera: Lasiocroton and Leucocroton. A study based on: (1) scanning electron microscopy of pollen and trichomes, (2) macromorphology, and (3) molecular data, was conducted to reveal generic relationships within this group. Phylogenies were based on parsimony and Bayesian analyses of nucleotide sequences of the ITS regions of the nuclear ribosomal DNA and the non-coding chloroplast DNA spacers psbM-trnD and ycf6-pcbM. One species, Lasiocroton trelawniensis, was transferred from the tribe into the genus Bernardia. Of the remaining species, three major monophyletic assemblages were revealed, one was restricted to limestone ares of Hispaniola and was sister to a clade with two monophyletic genera, Lasiocroton and Leucocroton. Morphological, biogeographical, and ecological data provided additional support for each of these three monophyletic assemblages. The Hispaniolan taxa were accommodated in a new genus with four species: Garciadelia. Leucocroton includes the nickel hyperaccumulating species from serpentine soils of Cuba, while the rest of the species were placed in Lasiocroton, a genus restricted to limestone areas. The geographic history of the islands as well as the phylogenetic placement of the Leucocroton-alliance, allows the research to include the historical biogeography of the alliance across the islands of the Caribbean based on a dispersal-vicariance analysis. The alliance arose on Eastern Cuba and Hispaniola, with Lasiocroton and Leucocroton diverging on Eastern Cuba according to soil type. Within Leucocroton, the analysis shows two migrations across the serpentine soils of Cuba. Additional morphological, ecological, and phylogenetic analyses support four new species in Cuba (Lasiocroton gutierrezii) and Hispaniola ( Garciadelia abbottii, G. castilloae, and G. mejiae). ^
Resumo:
Date of Acceptance: 30/8/15 Acknowledgements We thank the chief scientists, crew and company of the Japanese RV Hakuho-Maru (KH0703 and KH0803), the RV Tansei-Maru (KT-09-03), the RV Kairei (KR0716), the German FS Sonne (SO197 and SO 209) and the New Zealand RV Kaharoa (KAH0190, KAH1109, KAH1202, KAH1301 and KAH1310). This work was supported by the HADEEP projects, funded by the Nippon Foundation, Japan (2009765188), the Natural Environmental Research Council, UK (NE/E007171/1) and the Total Foundation, France. We acknowledge additional support from the Marine Alliance for Science and Technology for Scotland (MASTS) funded by the Scottish Funding Council (Ref: HR09011) and contributing institutions. We also acknowledge support from the Leverhulme Research Fellowship granted to SBP. Additional sea time was supported by NIWA’s ‘Impact of Resource Use on Vulnerable Deep-Sea Communities’ project (CO1_0906). From NIWA we thank Malcolm Clark, Ashley Rowden, Kareen Schnabel, Sadie Mills for logistical support at the NIWA Invertebrate Collection. We also thank Fredrik Søreide from Promare, USA, for supply of the Puerto-Rico samples, Marius Wenzel for helpful comments on manuscript drafts, and Dr. Tammy Horton (NOCS, UK) for identifying some of the earlier amphipod samples
Resumo:
Aim To relate the recent Iberian lynx decline to changes in the distribution of the European rabbit after the haemorrhagic disease outbreak of 1989. As Iberian rabbits evolved in two geographically separated lineages, being the recent lynx range practically restricted to the southwestern lineage, we also test if differential range dynamics exists for these lineages, with the consequent implications for lynx conservation and reintroduction planning.