Montag, 19 Dezember 2022 17:09

TEGELSTRÖM, H. & SJÖBERG, G. (1995)

Introduced Swedish Canada Geese (Branta canadensis) have low levels of genetic variation as revealed by DNA fingerprinting.

Journal of Evolutionary Biology 8(2):195-207. ISSN 1010-061X.

Abstract:

The Swedish, Finnish and Norwegian population of Canada geese (Branta canadensis), now amounting to some 30-50000 birds, was founded by only five individuals. We used DNA fingerprinting to assess the level of genetic variability.

tegelström-biblio

Freigegeben in T

A phylogenetic analysis of Brycon and Henochilus (Characiformes, Characidae, Bryconinae) based on the mitochondrial gene 16S rRNA.

Genetics and Molecular Biology, 31 (1,  suppl): 366-371

Abstract:

The genus Brycon, the largest subunit of the Bryconinae, has 42 valid species distributed from southern Mexico to the La Plata River in Argentina. Henochilus is a monotypic genus, comprising a single species (H. wheatlandii) found in the upper Rio Doce basin. In the present study, partial sequences of the mitochondrial gene 16S were obtained for fifteen species of Brycon and for Henochilus wheatlandii. The results showed that the genus Brycon is paraphyletic, since Henochilus is the sister-group of B. ferox and B. insignis. The most basal species analyzed were the trans-Andean species B. henni, B. petrosus, and B. chagrensis.

wagner-biblio

Freigegeben in W

The endangered species Brycon orbignyanus: genetic analysis and definition of priority areas for conservation.

Environ Biol Fish 98: 1845–1855. https://doi.org/10.1007/s10641-015-0402-8

Abstract:

Currently, biodiversity is threatened by several factors often associated with human population growth and the extension of areas occupied by human activity. In particular, freshwater fish fauna is affected by overfishing, deforestation, water pollution, introduction of exotic species and habitat fragmentation promoted by hydroelectric dams, among other environmental impact factors. Several action plans to preserve ichthyofauna biodiversity have been adopted; however, these plans frequently cover only a small number of species, and decisions are often made without strong scientific support. This study aimed to evaluate the genetic aspects of wild groups of Brycon orbignyanus, an endangered fish species, using microsatellites and D-loop regions to identify the genetic structure of the samples and to establish priority areas for conservation based on the genetic patterns of this species. The results indicated that the samples showed levels of genetic variability compatible with others studies with Neotropical fishes. However, the results obtained in the analysis of molecular variance (AMOVA) for microsatellites (F ST = 0.258) and D-loop (F ST = 0.234) and the interpopulation fixation index revealed that B. orbignyanus was structured in different subpopulations in the La Plata River basin; the areas with better environmental conditions also showed subgroups with higher rates of genetic variability. Future conservation actions addressing these sites should consider two different management units: the complex formed by the Ivinhema River, Upper Paraná, Camargo Port and Ilha Grande groups; and the complex formed by the Verde River and Sucuriu River groups.

ashikaga-biblio

Freigegeben in A

Genetic evidence for the origin of the agrimi goat (Capra aegagrus cretica).

Journal of Zoology, London 256: 369–377.

Abstract:

The agrimi goat Capra aegagrus cretica is unique to Crete and its offshore islands. It has been identfied as a sub-species of the wild bezoar goat Capra aegagrus aegagrus Erxleben, 1777, which it closely resembles in horn  shape, body form and coloration. This classification has been disputed by some researchers who claim that the agrimi are feral goats, derived from early domestic stock brought to the island by the first Neolithic settlers. In order to clarify this issue, DNA analyses (cytochromeband D loop sequences) were carried out on tissue of live and skeletonized agrimi and compared to sequences of wild and domestic caprines. Results conclusively show the agrimi to be a feral animal, that clades with domestic goats (Capra hircus) rather than with wild Asiatic bezoar. This study demonstrates that morphometric criteria do not necessarily reflect genetic affinities, and that the taxonomic classification of agrimi should be revised.

bar-gal-biblio

Freigegeben in B

Systematics of the Damon variegatus group of African whip spiders (Chelicerata: Amblypygi): Evidence from behaviour, morphology and DNA.

Organisms, Diversity & Evolution 5 (2005): 203–236.


Abstract:

The African whip spider, Damon variegatus, exhibits a broad, discontinuous distribution from the Congo, through western Tanzania and Zimbabwe, to South Africa and Namibia. Variation in size, number of antenniform leg segments, and colouration, taken together with a discontinuous distribution, suggest that allopatric populations of D. variegatus may be reproductively isolated, and more than one species may be involved. Furthermore, many morphological characters of D. variegatus appear to be plesiomorphic if compared to closely related species, suggesting that D. variegatus might be paraphyletic, regardless of whether it is a single panmictic species or a group of partly or entirely reproductively isolated populations. This contribution attempts to determine whether D. variegatus is monophyletic and comprises more than one species, by investigating three sources of evidence: behaviour, morphology and DNA. Mating behaviour is observed and mate-recognition trials conducted between males and females from several populations of D. variegatus and related species of Damon. The morphology of spermatophores obtained during these matings is studied and a matrix of somatic and genitalic characters produced. These morphological data are analysed separately and in combination with DNA sequences from loci of three genes in the nuclear genome (18S rDNA, 28S rDNA and Histone H3) and three genes in the mitochondrial genome (12S rDNA, 16S rDNA and Cytochrome Oxidase I). Neither the comparative behavioural evidence gathered nor the spermatophore morphology conclusively suggest that D. variegatus comprises more than one species. However, the molecular data, analysed separately and in combination with the morphological data, reveal that D. variegatus is monophyletic and that the population of D. variegatus to the west of the Kalahari sand system (Namibia and southern Angola) is specifically distinct from those to the east. This new species is described as Damon sylviae, the diagnosis of D. variegatus s. str. is revised, and a key to the species of the D. variegatus group is provided.

Freigegeben in P
Montag, 27 November 2017 14:22

DUBEY, S., LEUENBERGER, J. PERRIN, N. (2014)

Multiple origins of invasive and ‘native’ water frogs (Pelophylax spp.) in Switzerland.

Biological Journal of the Linnean Society. 112. DOI: 10.1111/bij.12283

Abstract:

The marsh frog (Pelophylax ridibundus) has been introduced in many areas in Central and Western Europe as a result of commercial trade with Eastern Europe, and is rapidly replacing the native pool frog (P. lessonae). A large number of Pelophylax species are distributed in Eastern Europe and the strong phenotypic similarity between these species is rendering their identification hazardous. Consequently, alien populations of Pelophylax might not strictly be composed of P. ridibundus as previously suspected. In the present study, we analysed the cytochrome-b and NADH dehydrogenase subunit 3 genes of introduced and native Pelophylax species from Switzerland (299 individuals) in order to properly identify the source populations of the invaders and the genetic status of the native species. Our study highlighted the occurrence of several genetic lineages of invasive frogs in western Switzerland. Unexpectedly, we also showed that several populations of the native pool frog (P. lessonae) cluster with the Italian pool frog P. bergeri from central Italy (considered by some authors as a subspecies of P. lessonae). Hence, these populations are probably also the result of introductions, meaning that the number of native P. lessonae populations is fewer than expected in Switzerland. These findings have important implications concerning the conservation of the endemic pool frog populations, as the presence of multiple alien species could strongly affect their long-term subsistence.

Multiple origins of invasive and ‘native’ water frogs (Pelophylax spp.) in Switzerland.

Available from: https://www.researchgate.net/publication/261675084_Multiple_origins_of_invasive_and_%27native%27_water_frogs_Pelophylax_spp_in_Switzerland [accessed Nov 27 2017].

Freigegeben in D

Phylogenetics, classification, and biogeography of the treefrogs.

Zootaxa 4104(1):. 1–109.
ISSN: 1175-5326 (print edition; ISSN: 1175-5334 (online edition). http://doi.org/10.11646/zootaxa.4104.1.1.

Abstract:

A phylogenetic analysis of sequences from 503 species of hylid frogs and four outgroup taxa resulted in 16,128 aligned sites of 19 genes. The molecular data were subjected to a maximum likelihood analysis that resulted in a new phylogenetic tree of treefrogs. A conservative new classification based on the tree has (1) three families composing an unranked taxon, Arboranae, (2) nine subfamilies (five resurrected, one new), and (3) six resurrected generic names and five new generic names. Using the results of a maximum likelihood timetree, times of divergence were determined. For the most part these times of divergence correlated well with historical geologic events. The arboranan frogs originated in South America in the Late Mesozoic or Early Cenozoic. The family Pelodryadidae diverged from its South American relative, Phyllomedusidae, in the Eocene and invaded Australia via Antarctica. There were two dispersals from South America to North America in the Paleogene. One lineage was the ancestral stock of Acris and its relatives, whereas the other lineage, subfamily Hylinae, differentiated into a myriad of genera in Middle America.

Auszug:

Hyla infrafrenata” Günther is a highly enigmatic species. Molecular data (99% bootstrap support) clearly place it in Nyctimystes, whereas morphologically it is like Litoria in having a orizontal pupil and no reticulations on the palpebral membrane (Tyler 1968). Furthermore, unlike species of Nyctimystes, it breeds in ponds and has pigmented eggs that hatch into tadpoles with small  anteroventral mouths (Anstis 2013).Last, it is the only pelodryadid known to have a chromosome complement of 2n = 24 (Menzies & Tippet 1976). The taxonomic position  of  this  species  awaits  more data and further interpretation to determine if it belongs in Litoria, Nyctimystes, or in its own genus; if the latter, the generic name Sandyrana Wells and Wellington is available

Freigegeben in D
Donnerstag, 13 April 2017 15:13

KOEPFLI, K. P., POLLINGER, J. et al. (2015)

und 22 (!) weitere Ko-Autoren.


Genome-wide Evidence Reveals that African and Eurasian Golden Jackals Are Distinct Species.

Current Biology 25 (16): 2158–2165. 17 August 2015. Published Online: July 30, 2015.
DOI: http://dx.doi.org/10.1016/j.cub.2015.06.060

Summary:

The golden jackal of Africa (Canis aureus) has long been considered a conspecific of jackals distributed throughout Eurasia, with the nearest source populations in the Middle East. However, two recent reports found that mitochondrial haplotypes of some African golden jackals aligned more closely to gray wolves (Canis lupus) [ 1, 2 ], which is surprising given the absence of gray wolves in Africa and the phenotypic divergence between the two species. Moreover, these results imply the existence of a previously unrecognized phylogenetically distinct species despite a long history of taxonomic work on African canids. To test the distinct-species hypothesis and understand the evolutionary history that would account for this puzzling result, we analyzed extensive genomic data including mitochondrial genome sequences, sequences from 20 autosomal loci (17 introns and 3 exon segments), microsatellite loci, X- and Y-linked zinc-finger protein gene (ZFX and ZFY) sequences, and whole-genome nuclear sequences in African and Eurasian golden jackals and gray wolves. Our results provide consistent and robust evidence that populations of golden jackals from Africa and Eurasia represent distinct monophyletic lineages separated for more than one million years, sufficient to merit formal recognition as different species: C. anthus (African golden wolf) and C. aureus (Eurasian golden jackal). Using morphologic data, we demonstrate a striking morphologic similarity between East African and Eurasian golden jackals, suggesting parallelism, which may have misled taxonomists and likely reflects uniquely intense interspecific competition in the East African carnivore guild. Our study shows how ecology can confound taxonomy if interspecific competition constrains size diversification.

Freigegeben in K
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