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1.
Mol Phylogenet Evol ; 134: 35-49, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30703516

RESUMO

The process of species diversification is often associated with niche shifts in the newly arising lineages so that interspecific competition is minimized. However, an opposing force known as niche conservatism causes that related species tend to resemble each other in their niche requirements. Due to the inherent multidimensionality of niche space, some niche components may be subject to divergent evolution while others remain conserved in the process of speciation. One such possible component is the species' climatic niche. Here, we test the role of climatic niche evolution on the diversification of the Old World cat snakes of the genus Telescopus. These slender, nocturnal snakes are distributed in arid and semiarid areas throughout Africa, southwest Asia and adjoining parts of Europe. Because phylogenetic relationships among the Telescopus species are virtually unknown, we generated sequence data for eight genetic markers from ten of the 14 described species and reconstructed a time-calibrated phylogeny of the genus. Phylogenetic analysesindicate that the genus is of considerably old origin that dates back to the Eocene/Oligocene boundary. Biogeographical analyses place the ancestor of the genus in Africa, where it diversified into the species observed today and from where it colonized Arabia and the Levant twice independently. The colonization of Arabia occurred in the Miocene, that of the Levant either in the Late Oligocene or Early Miocene. We then identified temperature and precipitation niche space and breadth of the species included in the phylogeny and examined whether there is phylogenetic signal in these climatic niche characteristics. Despite the vast range of the genus and its complex biogeographic history, most Telescopus species have similar environmental requirements with preference for arid to semiarid conditions. One may thus expect that the genus' climatic niche will be conserved. However, our results suggest that most of the climatic niche axes examined show no phylogenetic signal, being indicative of no evolutionary constraints on the climatic niche position and niche breadth in Telescopus. The only two variables with positive phylogenetic signal (temperature niche position and precipitation niche breadth) evolved under the Brownian motion model, also indicating no directional selection on these traits. As a result, climatic niche evolution does not seem to be the major driver for the diversification in Telescopus.


Assuntos
Evolução Biológica , Clima , Colubridae/classificação , Filogeografia , África , Animais , Arábia , Teorema de Bayes , Calibragem , Filogenia , Análise de Componente Principal , Chuva , Temperatura , Fatores de Tempo
2.
Mol Phylogenet Evol ; 127: 288-303, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29551523

RESUMO

Members of the snake subfamily Aparallactinae occur in various habitats throughout sub-Saharan Africa. The monophyly of aparallactine snakes is well established, but relationships within the subfamily are poorly known. We sampled 158 individuals from six of eight aparallactine genera in sub-Saharan Africa. We employed concatenated gene-tree analyses, divergence dating approaches, and ancestral-area reconstructions to infer phylogenies and biogeographic patterns with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). As a result, we uncover several cryptic lineages and elevate a lineage of Polemon to full species status. Diversification occurred predominantly during the Miocene, with a few speciation events occurring subsequently in the Pliocene and Pleistocene. Biogeographic analyses suggested that the Zambezian biogeographic region, comprising grasslands and woodlands, facilitated radiations, vicariance, and dispersal for many aparallactines. Moreover, the geographic distributions of many forest species were fragmented during xeric and cooler conditions, which likely led to diversification events. Biogeographic patterns of aparallactine snakes are consistent with previous studies of other sub-Saharan herpetofauna.


Assuntos
Clima Desértico , Lagartos/anatomia & histologia , Lagartos/classificação , Filogenia , Filogeografia , África Subsaariana , Animais , DNA Mitocondrial/genética , Funções Verossimilhança , Lagartos/genética , Serpentes/anatomia & histologia , Serpentes/genética
3.
Proc Biol Sci ; 284(1851)2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28356450

RESUMO

How evolutionary novelties evolve is a major question in evolutionary biology. It is widely accepted that changes in environmental conditions shift the position of selective optima, and advancements in phylogenetic comparative approaches allow the rigorous testing of such correlated transitions. A longstanding question in vertebrate biology has been the evolution of terrestrial life histories in amphibians and here, by investigating African bufonids, we test whether terrestrial modes of reproduction have evolved as adaptations to particular abiotic habitat parameters. We reconstruct and date the most complete species-level molecular phylogeny and estimate ancestral states for reproductive modes. By correlating continuous habitat measurements from remote sensing data and locality records with life-history transitions, we discover that terrestrial modes of reproduction, including viviparity evolved multiple times in this group, most often directly from fully aquatic modes. Terrestrial modes of reproduction are strongly correlated with steep terrain and low availability of accumulated water sources. Evolutionary transitions to terrestrial modes of reproduction occurred synchronously with or after transitions in habitat, and we, therefore, interpret terrestrial breeding as an adaptation to these abiotic conditions, rather than an exaptation that facilitated the colonization of montane habitats.


Assuntos
Bufonidae/fisiologia , Meio Ambiente , Reprodução , Animais , Evolução Biológica , Filogenia
4.
PLoS One ; 14(4): e0214889, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30995262

RESUMO

Atractaspidines are poorly studied, fossorial snakes that are found throughout Africa and western Asia, including the Middle East. We employed concatenated gene-tree analyses and divergence dating approaches to investigate evolutionary relationships and biogeographic patterns of atractaspidines with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). We sampled 91 individuals from both atractaspidine genera (Atractaspis and Homoroselaps). Additionally, we used ancestral-state reconstructions to investigate fang and diet evolution within Atractaspidinae and its sister lineage (Aparallactinae). Our results indicated that current classification of atractaspidines underestimates diversity within the group. Diversification occurred predominantly between the Miocene and Pliocene. Ancestral-state reconstructions suggest that snake dentition in these taxa might be highly plastic within relatively short periods of time to facilitate adaptations to dynamic foraging and life-history strategies.


Assuntos
Viperidae/classificação , Viperidae/genética , Estruturas Animais/anatomia & histologia , Estruturas Animais/fisiologia , Animais , Citocromos b/genética , Evolução Molecular , Genes Mitocondriais , Genes RAG-1 , Genes mos , NADH Desidrogenase/genética , Filogenia , Comportamento Predatório , RNA Ribossômico 16S/genética , Fatores de Tempo , Viperidae/fisiologia
5.
Zootaxa ; 4462(4): 483-496, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-30313454

RESUMO

Telescopus pulcher is an enigmatic colubrid snake only known from the holotype and paratype specimens described from 'Migiurtinia' in Puntland (Somalia) in 1935. Herein we recorded the third and fourth-ever known specimens of this species from the Toon village, Woqooyi Galbeed Region, and 15 km southeast of Sheikh, Saahil Region, Somaliland. The species is endemic to Somaliland and adjoining parts of Ethiopia and Puntland. Data on morphology and natural history, as well as the first photographs of live specimens are provided. We also provide a detailed description of the paratype. The coloration of the species resembles that of the vipers of the genus Echis and we hypothesize that T. pulcher mimics these common and sympatric vipers in the Horn of Africa.


Assuntos
Colubridae , Serpentes , Animais , Etiópia , Lagartos , Somália
7.
PLoS One ; 13(2): e0190389, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29414999

RESUMO

In the present work, we use an exceptional database including 5,359 records of 101 species of Oman's terrestrial reptiles together with spatial tools to infer the spatial patterns of species richness and endemicity, to infer the habitat preference of each species and to better define conservation priorities, with especial focus on the effectiveness of the protected areas in preserving this unique arid fauna. Our results indicate that the sampling effort is not only remarkable from a taxonomic point of view, with multiple observations for most species, but also for the spatial coverage achieved. The observations are distributed almost continuously across the two-dimensional climatic space of Oman defined by the mean annual temperature and the total annual precipitation and across the Principal Component Analysis (PCA) of the multivariate climatic space and are well represented within 17 out of the 20 climatic clusters grouping 10% of the explained climatic variance defined by PC1 and PC2. Species richness is highest in the Hajar and Dhofar Mountains, two of the most biodiverse areas of the Arabian Peninsula, and endemic species richness is greatest in the Jebel Akhdar, the highest part of the Hajar Mountains. Oman's 22 protected areas cover only 3.91% of the country, including within their limits 63.37% of terrestrial reptiles and 50% of all endemics. Our analyses show that large areas of the climatic space of Oman lie outside protected areas and that seven of the 20 climatic clusters are not protected at all. The results of the gap analysis indicate that most of the species are below the conservation target of 17% or even the less restrictive 12% of their total area within a protected area in order to be considered adequately protected. Therefore, an evaluation of the coverage of the current network of protected areas and the identification of priority protected areas for reptiles using reserve design algorithms are urgently needed. Our study also shows that more than half of the species are still pending of a definitive evaluation by the International Union for Conservation of Nature (IUCN).


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/métodos , Répteis/classificação , Animais , Clima , Ecossistema , Omã
8.
Zootaxa ; 4117(4): 529-42, 2016 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-27395191

RESUMO

Hemidactylus laevis, a gekkonid lizard originally described from the Gaan Libah Mountains in Somaliland, is recorded herein from Erigavo, Sanaag Region, in the same state, which represents the second-ever known specimen and locality for this species in more than 100 years since its description. The species is endemic to Somaliland. Data on morphology and natural history, as well as the first life photographs are provided. Based on morphological data we conclude the species to be closely related to H. laticaudatus. Additionally, H. fragilis from southern Somalia and extreme south-east Ethiopia is resurrected from the synonymy of H. frenatus based on morphological data.


Assuntos
Lagartos/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Ecossistema , Etiópia , Feminino , Lagartos/anatomia & histologia , Lagartos/crescimento & desenvolvimento , Masculino , Tamanho do Órgão , Somália
9.
Zootaxa ; 3835(1): 33-58, 2014 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-25081434

RESUMO

A molecular phylogeny of the sphaerodactylid geckos of the genus Pristurus is inferred based on an alignment of 1845 base pairs (bp) of concatenated mitochondrial (12S) and nuclear (acm4, cmos, rag1 and rag2) genes for 80 individuals, representing 18 of the 23-26 species, and the three subspecies of P. rupestris. The results indicate that P. rupestris is polyphyletic and includes two highly divergent clades: the eastern clade, found in coastal Iran and throughout the Hajar Mountain range in northern Oman and eastern UAE; and the western clade, distributed from central coastal Oman, through Yemen, Saudi Arabia and north to southern Jordan. Inferred haplotype networks for the four nuclear genes show that the eastern and western clades of "P. rupestris" are highly differentiated and do not share any alleles. Moreover, although the two clades are differentiated by a morphological multivariate analysis, no one character or set of characters was found to be diagnostic. Based on the molecular analysis of specimens from the type locality of P. rupestris rupestris, the name P. rupestris is applied to the eastern clade. The name that should apply to the western clade cannot be clarified until morphological and genetic data for "P. rupestris" is available from the vicinity of Bosaso, Somalia, and therefore we refer to it as Pristurus sp. 1. The phylogenetic tree of Pristurus supports the hypothesis that P. celerrimus is sister to all the other species in the analyses and that the Socotra Archipelago was independently colonized a minimum of two times.


Assuntos
Lagartos/classificação , Filogenia , Distribuição Animal , Animais , DNA Mitocondrial/genética , Lagartos/genética , Oriente Médio , Somália
10.
Syst Parasitol ; 59(1): 71-4, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15318022

RESUMO

Coprological examination of nine bush vipers Atheris chlorechis imported from Ghana revealed the presence of a new coccidian species belonging to Eimeria Schneider, 1875. Thin walled oöcysts of Eimeria atheridis n. sp. are spherical to slightly subspherical, 22.8 (19-26) x 22.5 (19-25) microm, without micropyle, polar granule and oöcyst residuum. Sporocysts are elongately ellipsoidal, 17.1 (15-19) x 7.5 (6-8) microm, with a dome like, relatively flat Stieda body. Sporozoites possess two refractile bodies and distinct transversal striation. Based on the presence of a Stieda body the species described herein clearly belongs to the Eimeria ( sensu stricto ).


Assuntos
Eimeria/ultraestrutura , Viperidae/parasitologia , Animais , Fezes , Gana , Microscopia de Interferência , Oocistos/ultraestrutura
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