138 research outputs found
Contrasting evolutionary histories of the legless lizards slow worms (Anguis) shaped by the topography of the Balkan Peninsula
Background: Genetic architecture of a species is a result of historical changes in population size and extent of distribution related to climatic and environmental factors and contemporary processes of dispersal and gene flow. Population-size and range contractions, expansions and shifts have a substantial effect on genetic diversity and intraspecific divergence, which is further shaped by gene-flow limiting barriers. The Balkans, as one of the most important sources of European biodiversity, is a region where many temperate species persisted during the Pleistocene glaciations and where high topographic heterogeneity offers suitable conditions for local adaptations of populations. In this study, we investigated the phylogeographical patterns and demographic histories of four species of semifossorial slow-worm lizards (genus Anguis) present in the Balkan Peninsula, and tested the relationship between genetic diversity and topographic heterogeneity of the inhabited ranges. Results: We inferred phylogenetic relationships, compared genetic structure and historical demography of slow worms using nucleotide sequence variation of mitochondrial DNA. Four Anguis species with mostly parapatric distributions occur in the Balkan Peninsula. They show different levels of genetic diversity. A signature of population growth was detected in all four species but with various courses in particular populations. We found a strong correlation between genetic diversity of slow-worm populations and topographic ruggedness of the ranges (mountain systems) they inhabit. Areas with more rugged terrain harbour higher genetic diversity. Conclusions: Phylogeographical pattern of the genus Anguis in the Balkans is concordant with the refugiawithin- refugia model previously proposed for both several other taxa in the region and other main European Peninsulas. While slow-worm populations from the southern refugia mostly have restricted distributions and have not dispersed much from their refugial areas, populations from the extra-Mediterranean refugia in northern parts of the Balkans have colonized vast areas of eastern, central, and western Europe. Besides climatic historical events, the heterogeneous topography of the Balkans has also played an important role in shaping genetic diversity of slow worms.BMC Evolutionary Biology (2016), 16(1): 9
Two newly recognized species of Hemidactylus (Squamata, Gekkonidae) from the Arabian Peninsula and Sinai, Egypt
This is an open access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC-BY),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.A recent molecular phylogeny of the Arid clade of the genus Hemidactylus revealed that the recently described H. saba and two unnamed Hemidactylus species from Sinai, Saudi Arabia and Yemen form a well-supported monophyletic group within the Arabian radiation of the genus. The name 'Hemidactylus saba species group' is suggested for this clade. According to the results of morphological comparisons and the molecular analyses using two mitochondrial (12S and cytb) and four nuclear (cmos, mc1r, rag1, rag2) genes, the name Hemidactylus granosus Heyden, 1827 is resurrected from the synonymy of H. turcicus for the Sinai and Saudi Arabian species. The third species of this group from Yemen is described formally as a new species H. ulii sp. n. The phylogenetic relationships of the members of 'Hemidactylus saba species group' are evaluated and the distribution and ecology of individual species are discussed. © JiĆĂ Ć mĂd et al.The study was supported by the NAKI project of the Ministry of Culture of the Czech Republic (# DF12P01OVV021 MKÄR to JĆ and JM), by grant CGL2012-36970 to SC from the Ministerio de EconomĂa y Competitividad, Spain (co-funded by FEDER). We are thankful to the Deanship of academic research at Taif University for funding the sample collection in Saudi Arabia (Grant no. 1-433-2108) and to Omer Baeshen, Environment Protection Agency, Sana'a, Republic of Yemen for issuing the collecting permit (Ref 10/2007).Peer Reviewe
Bringing Authoring Tools for Intelligent Tutoring Systems and Serious Games Closer Together: Integrating GIFT with the Unity Game Engine
In an effort to bring intelligent tutoring system (ITS) authoring tools closer to content authoring tools, the authors are working to integrate GIFT with the Unity game engine and editor. The paper begins by describing challenges faced by modern intelligent tutors and the motivation behind the integration effort, with special consideration given to how this work will better meet the needs of future serious games. The next three sections expand on these major hurdles more thoroughly, followed by proposed design enhancements that would allow GIFT to overcome these issues. Finally, an overview is given of the authorsâ current progress towards implementing the proposed design. The key contribution of this work is an abstraction of the interface between intelligent tutoring systems and serious games, thus enabling ITS authors to implement more complex training behaviors
No ecological opportunity signal on a continental scale?:Diversification and life-history evolution of african true toads (Anura: Bufonidae)
The niche-filling process predicted by the âecological opportunityâ (EO) model is an often-invoked mechanism for generating exceptional diversity in island colonizers. Whether the same process governs lineage accumulation and trait disparity during continental colonization events is less clear. Here, we test this prediction by investigating the rate dynamics and trait evolution of one of Africa's most widespread amphibian colonizers, the true toads (Bufonidae). By reconstructing the most complete molecular phylogeny of African Bufonidae to date, we find that the diversification of lineages in Africa best conforms to a constant rate model throughout time and across subclades, with little support for EO. Evolutionary rates of life-history traits have similarly been constant over time. However, an analysis of generalists and specialists showed a shift toward higher speciation rates associated with habitat specialization. The overall lack of EO signal can be interpreted in a number of ways and we propose several explanations. Firstly, methodological issues might preclude the detection of EO. Secondly, colonizers might not experience true EO conditions and due to the size, ecological heterogeneity and age of landmasses, the diversification processes might be more complex. Thirdly, lower speciation rates of habitat generalists may have affected overall proliferation of lineages
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009aâb; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
Amphibians recorded in the Bamenda Highlands, Cameroon
An endemics species of Amphibians were recorded in the Bamenda Highlands, Cameroon
Inter-species and intra-species variability of Hyla savignyi and Hyla arborea
Department of ZoologyKatedra zoologieFaculty of SciencePĆĂrodovÄdeckĂĄ fakult
Phenotypic and molecular approaches in the systematics of the Palearctic and Neotropic tree frogs, Hyla and Osteocephalus (Amphibia: Hylidae)
The systematics and taxonomy of tree frogs of the family Hylidae has undergone turbulent changes both at higher (subfamilies, genera) and lower (species) level during the last decades. The original approach used morphological characters to distinguish tree frogs. It has been completed by bioacoustics, since the advertisement calls of the males were in some cases found to represent an important behavioural reproductive barrier and therefore useful for systematic evaluations. However, a completely new impulse was given to systematics by the introduction of modern genetic methods. These methods have allowed to distinguish not only morphologically but even acoustically cryptic taxa. The most reliable method to distinguish tree frogs at present is a combination of data from the different disciplines. The present dissertation thesis aims to evaluate the systematics of tree frogs of the genus Hyla from Eastern Europe and the Middle East as well as the systematics of the Amazonian genus Osteocephalus using a combination of morphological, bioacoustic and molecular approaches. The thesis is composed of a general introduction, three published papers, two manuscripts under reviews and a conclusion chapter. The first three papers deal with the phenotypic (morphological plus bioacustic) approach in systematic..
A new minute species of Pristimantis (Amphibia: Anura: Craugastoridae) with a large head from the Yanachaga-Chemillén National Park in central Peru, with comments on the phylogenetic diversity of Pristimantis occurring in the Cordillera Yanachaga
We describe a new minute species of the genus Pristimantis, P. boucephalus sp. nov., from the Yanachaga-ChemillĂ©n National Park, RegiĂłn Pasco, Peru. The description is based on a freshly collected male specimen found at 2950 m a.s.l. in a cloud forest and four previously unidentified museum specimens consisting of two adult males, one subadult female and a juvenile from the Yanachaga-ChemillĂ©n National Park. The new species is mainly characterized by a snoutâvent length of 13.4â14.5 mm in adult males (n = 3), and 12.5 mm in the only known subadult female, and is compared morphologically and genetically with other taxonomically and biogeographically relevant species of Pristimantis. The new species is characterized by its small size, disproportionally large head with short snout, absence of a tympanic annulus and membrane, and reddish-copper iris. Phylogenetically it belongs to a speciose clade, an as yet unnamed species group, comprising both montane (Andes, Guiana Shield) and lowland (Amazon) taxa from the northern part of South America. The new species is genetically close to the sympatric P. cruciocularis. Species of Pristimantis occurring in the Cordillera Yanachaga region in the Andes of central Peru are members of six divergent phylogenetic lineages.We describe a new minute species of the genus Pristimantis, P. boucephalus sp. nov., from the Yanachaga-ChemillĂ©n National Park, RegiĂłn Pasco, Peru. The description is based on a freshly collected male specimen found at 2950 m a.s.l. in a cloud forest and four previously unidentified museum specimens consisting of two adult males, one subadult female and a juvenile from the Yanachaga-ChemillĂ©n National Park. The new species is mainly characterized by a snoutâvent length of 13.4â14.5 mm in adult males (n = 3), and 12.5 mm in the only known subadult female, and is compared morphologically and genetically with other taxonomically and biogeographically relevant species of Pristimantis. The new species is characterized by its small size, disproportionally large head with short snout, absence of a tympanic annulus and membrane, and reddish-copper iris. Phylogenetically it belongs to a speciose clade, an as yet unnamed species group, comprising both montane (Andes, Guiana Shield) and lowland (Amazon) taxa from the northern part of South America. The new species is genetically close to the sympatric P. cruciocularis. Species of Pristimantis occurring in the Cordillera Yanachaga region in the Andes of central Peru are members of six divergent phylogenetic lineages.</p
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