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Dive into the research topics where Aziz Avcı is active.

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Featured researches published by Aziz Avcı.


Amphibia-reptilia | 2005

Age, size and growth of the southern crested newt Triturus karelinii (Strauch 1870) in a population from Bozdag (Western Turkey)

Kurtuluş Olgun; Nazan Üzüm; Aziz Avcı; Claude Miaud

We studied the characteristics of bone growth assessed by skeletochronology in a southern crested newt Triturus karelinii (Urodela) population from Western Turkey. The timing and patterns of bone arrested growth were observed using the phalanges of juveniles and adults that were caught in spring at a breeding site. A metamorphosis line was found in the juveniles. In some adults, a classical succession of single lines of arrested growth was observed in about 50% of the cross sections. However, the other adults exhibited a succession of double lines of arrested growth in their phalanges. Due to the arid summer and cold winter climate in the Bozdag region (1200 m a.s.l.), we argue that in this last case, the lines of arrested growth were deposited during both the summer (aestivation) and winter (wintering). Body length, age and growth were similar in males and females. The age of maturity was 3 to 4 years old and longevity was 8 and 11 years in males and females respectively. Body length and age among taxonomically related large bodied newts of the T. cristatus complex were reported from populations experiencing various environmental conditions. Body length and age at maturity were similar to that observed in other newt species. However, longevity seems to be lower than expected in the T. karelinii studied population. We hypothesized that the arid climate of Bozdag could cause a higher mortality risk during the terrestrial phase of the life cycle. Studying more populations exposed to various conditions is clearly needed to assess interpopulational variation of these life-history traits in this newt species.


Evolution Letters | 2017

A genomic footprint of hybrid zone movement in crested newts

Ben Wielstra; Terry Burke; Roger K. Butlin; Aziz Avcı; Nazan Üzüm; Emin Bozkurt; Kurtuluş Olgun; Jan W. Arntzen

Speciation typically involves a stage in which species can still exchange genetic material. Interspecific gene flow is facilitated by the hybrid zones that such species establish upon secondary contact. If one member of a hybridizing species pair displaces the other, their hybrid zone would move across the landscape. Although theory predicts that moving hybrid zones quickly stagnate, hybrid zones tracked over one or a few decades do not always follow such a limitation. This suggests that hybrid zones have the potential to traverse considerable distances over extended periods of time. When hybrid zones move, introgression is predicted to result in biased gene flow of selectively neutral alleles, from the receding species into the advancing species. We test for such a genomic footprint of hybrid zone movement in a pair of crested newt species (genus Triturus) for which we have a priori support for westward hybrid zone movement. We perform a multilocus phylogeographical survey and conduct Bayesian clustering analysis, estimation of ancestry and heterozygosity, and geographical cline analysis. In a 600 km wide area east of the present day hybrid zone a genomic footprint constitutes empirical evidence consistent with westward hybrid zone movement. The crested newt case suggests that hybrid zone movement can occur over an extensive span of time and space. Inferring hybrid zone movement provides fundamental insight into historical biogeography and the speciation process, and we anticipate that hybrid zones will prove to be far more mobile than currently appreciated.


Molecular Phylogenetics and Evolution | 2016

Phylogeny and diversification of mountain vipers (Montivipera, Nilson et al., 2001) triggered by multiple Plio-Pleistocene refugia and high-mountain topography in the Near and Middle East.

Nikolaus Stümpel; Mehdi Rajabizadeh; Aziz Avcı; Wolfgang Wüster; Ulrich Joger

The Near and Middle East is a hotspot of biodiversity, but the region remains underexplored at the level of genetic biodiversity. Here, we present an extensive molecular phylogeny of the viperid snake genus Montivipera, including all known taxa. Based on nuclear and mitochondrial data, we present novel insights into the phylogeny of the genus and review the status of its constituent species. Maximum likelihood methods revealed a montane origin of Montivipera at 12.3Mya. We then analyzed factors of mountain viper diversity. Our data support substantial changes in effective population size through Plio-Pleistocene periods. We conclude that climatic oscillations were drivers of allopatric speciation, and that mountain systems of the Near and Middle East have strongly influenced the evolution and survival of taxa, because climatic and topographical heterogeneities induced by mountains have played a crucial role as filters for dispersal and as multiple refugia. The wide diversity of montane microhabitats enabled mountain vipers to retain their ecological niche during climatic pessima. In consequence the varied geological and topographical conditions between refugia favoured genetic isolation and created patterns of species richness resulting in the formation of neoendemic taxa. Our data support high concordance between geographic distributions of Montivipera haplotypes with putative plant refugia.


Molecular Phylogenetics and Evolution | 2016

A reinvestigation of phylogeny and divergence times of the Ablepharus kitaibelii species complex (Sauria, Scincidae) based on mtDNA and nuDNA genes

Eirini Skourtanioti; Paschalia Kapli; Çetin Ilgaz; Yusuf Kumlutaş; Aziz Avcı; Faraham Ahmadzadeh; Jelka Crnobrnja-Isailović; Iulian Gherghel; Petros Lymberakis; Nikos Poulakakis

Morphological and DNA data support that the East Mediterranean snake-eyed skink Ablepharus kitaibelii represents a species complex that includes four species A. kitaibelii, A. budaki, A. chernovi, and A. rueppellii, highlighting the need of its taxonomic reevaluation. Here, we used Bayesian and Maximum Likelihood methods to estimate the phylogenetic relationships of all members of the complex based on two mitochondrial (cyt b, 16S rRNA) and two nuclear markers (MC1R, and NKTR) and using Chalcides, Eumeces, and Eutropis as outgroups. The biogeographic history of the complex was also investigated through the application of several phylogeographic (BEAST) and biogeographic (BBM) analyses. Paleogeographic and paleoclimatic data were used to support the inferred phylogeographic patterns. The A. kitaibelli species complex exhibits high genetic diversity, revealing cases of hidden diversity and cases of non-monophyletic species such as A. kitaibelii and A. budaki. Our results indicate that A. pannonicus branches off first and a group that comprises specimens of A. kitaibelli and A. budaki from Kastelorizo Island group (southeast Greece) and southwest Turkey, respectively is differentiated from the rest A. kitaibelli and A. budaki populations and may represent a new species. The estimated divergence times place the origin of the complex in the Middle Miocene (∼16Mya) and the divergence of most currently recognized species in the Late Miocene. The inferred ancestral distribution suggests that the complex originated in Anatolia, supposing that several vicariance and dispersal events that are related with the formation of the Mid-Aegean Trench, the Anatolian Diagonal and the orogenesis of the mountain chains in southern and eastern Anatolia have led to current distribution pattern of A. kitaibelii species complex in the Balkans and Middle East.


Zoology in The Middle East | 2014

Modelling the potential distribution of the Bridled Skink, Trachylepis vittata (Olivier, 1804), in the Middle East

Razieh Fattahi; Gentile Francesco Ficetola; Nasrullah Rastegar-Pouyani; Aziz Avcı; Yusuf Kumlutaş; Çetin Ilgaz; Seyyed Saeed Hosseinian Yousefkhani

The Bridled Skink, Trachylepis vittata, is widespread in the Middle East and eastern coastal Mediterranean areas and inhabits foothills throughout the arid regions of the Middle East. With the help of more than 146 distribution records from Iran, Turkey, Syria, Israel, Jordan, Cyprus, Egypt, Lebanon and Libya, we analysed the influence of climate on the distribution pattern. According to the Maximum Entropy model, the most influential factors that determined T. vittata distribution are: precipitation of coldest quarter, Normalised Difference Vegetation Index (NDVI) and precipitation in the warmest quarter. The model suggests that the western slopes of the Zagros Mountains in Iran and slopes in the southern regions of Anatolia around the Mediterranean Sea are suitable for this species. The species is associated with areas with intermediate NDVI (150-180) (a measure of primary productivity), high winter precipitation (>300 mm) and dry summer (<50mm). The association with rainy winter limits the presence of the species in lowlands. The Zagros Mountains may act as a biogeographic barrier that limits the species dispersal eastward, because of their scarce precipitation.


Italian Journal of Zoology | 2011

Body size and age structure of a breeding population portion of the Urmia salamander, Neurergus crocatus Cope, 1862 (Caudata: Salamandridae)

Nazan Üzüm; Aziz Avcı; Nurhayat Özdemir; Çetin Ilgaz; Kurtuluş Olgun

Abstract Recently, the Urmia salamander, Neurergus crocatus Cope, 1862 was classified as a vulnerable species. The age structure of a breeding population portion of N. crocatus from Turkey was studied by using skeletochronology performed on the phalanges. According to the analysis of the age structure based on counting lines of arrested growth (LAGs), ages ranged from 5 to 14 years (mean = 9.4 ± 2.3 years) for males and from 8 to 17 years (mean = 11.6 ± 2.2 years) for females in N. crocatus. The mean snout–vent length was 69.2 ± 3.6 mm in males and 76.2 ± 3.8 in females. The sexual dimorphism index was 0.10. The difference between the sexes in age and size was statistically significant.


Amphibia-reptilia | 2011

Description of four new Asaccus Dixon and Anderson, 1973 (Reptilia: Phyllodactylidae) from Iran and Turkey

Farhang Torki; Faraham Ahmadzadeh; Çetin Ilgaz; Aziz Avcı; Yusuf Kumlutaş

One new Asaccus from the Anatolian plateau and three new Asaccus from the Iranian plateau are described as follows. (1) Asaccus barani sp. nov.: diagnosed by strongly heterogeneous dorsal tubercles; (2) Asaccus iranicus sp. nov.: diagnosed by small body size and digits (forelimbs) parallel joint to palm; (3) Asaccus tangestanensis sp. nov.: by having enlarged trihedral tubercles all over the dorsal body; (4) Asaccus zagrosicus sp. nov.: secondary postmentals are not in contact with lowerlabials (100% of specimens). Other important data on the new Asaccus are given in detail in the text.


Amphibia-reptilia | 2013

Incongruence between taxonomy and genetics: three divergent lineages within two subspecies of the rare Transcaucasian rat snake (Zamenis hohenackeri)

Aziz Avcı; Václav Gvoždík; David Jandzik

Two morphologically differentiated subspecies with presumably allopatric distribution have traditionally been recognized in the rare Transcaucasian rat snake, Zamenis hohenackeri: Z. h. hohenackeri (Caucasus region and E Turkey, NW Iran and N Iraq) and Z. h. tauricus (S Anatolia and Levant). Both subspecies are sometimes considered just colour forms of a monotypic species. We used sequences of the mitochondrial gene cytochrome b to find out whether both subspecies are also genetically differentiated, or whether their haplotypes form a cluster without clear subdivision. We found that the species forms three divergent lineages: one corresponds to the nominotypic subspecies, another comprises an individual from the region of the type locality of Z. h. tauricus in southern Anatolia and the third, with no available name and separated from the previous by the Amanos (Nur) Mountains, is distributed in the Levant. The pattern of divergence and distribution of the lineages correspond to other species of amphibians and reptiles, demonstrating that similar geo-climatic events presumably formed genetic variation and triggered speciation processes in this region.


Amphibia-reptilia | 2014

First comprehensive insights into nuclear and mitochondrial DNA based population structure of Near East mountain brook newts (Salamandridae: genus Neurergus) suggest the resurrection of Neurergus derjugini

Ralf Hendrix; Jürgen Fleck; Willi Schneider; Christoph Schneider; Daniel Geller; Aziz Avcı; Kurtuluş Olgun; Sebastian Steinfartz

Due to their extraordinary coloration, mountain brook newts of the genus Neurergus found in the Near East have fascinated herpetologists since their initial description more than 150 years ago. Although the monophyly of Neurergus newts within the Salamandridae has been unambiguously shown for mitochondrial genes, and recent comprehensive molecular phylogenies placed Neurergus as a sister taxon of banded newts (genus Ommatotriton), we know almost nothing about the structure and relatedness of populations at the intraspecific level. In this study, we therefore analysed sequence variation of a mitochondrial DNA segment (covering a partial region of the control region and the 12S ribosomal RNA) from more than 100 individuals and of two nuclear genes (KIAA and SACS) for a representative subset of individuals originating from nine distinct populations, representing N. strauchii, N. crocatus and N. microspilotus. We also studied individuals of N. derjugini, a taxon that has long been synonymized as N. crocatus, and of which individuals have not been accessible to the scientific community since its original description in 1916. Our results suggest high genetic diversity of populations within species for the mitochondrial DNA marker, while the resolution of applied nuclear genes did not go beyond the level of species. For N. strauchii and N. crocatus, two species that inhabit the largest geographic ranges within the genus, we found a high proportion of diversity both within and between populations for the mitochondrial control region. Individuals of N. microspilotus and N. derjugini only displayed considerable genetic differentiation for one nuclear gene (SACS), while only very little or none genetic differentiation could be found for the mitochondrial control region and the KIAA gene, respectively. As both taxa are also morphologically not well differentiated, we suggest on the basis of the current dataset to taxonomically synonymize N. microspilotus due to priority reasons as N. derjugini. It can be therefore concluded that the most accurate taxonomy of the genus Neurergus should consider N. crocatus, N. strauchii, N. kaiseri and N. derjugini as valid taxonomic units at the species level.


Acta Herpetologica | 2010

Electrophoretic Comparison of Blood-serum Proteins of Apathya cappadocica (Sauria, Lacertidae) Subspecies from Anatolia

Çetin Ilgaz; Aziz Avcı; Yusuf Kumlutaş; Hüseyin Arikan

Blood-serum proteins of the known subspecies of Apathya cappadocica (Werner, 1902) were studied comparatively by polyacrylamide disc gel electrophoresis. In order to obtain useful biochemical data for classification, differences between the electrophoreograms of the samples included in the morphologically different subspe - cies were distinguished qualitatively and quantitatively. These comparisons indicated that electrophoretic results supported morphological discrimination of the known subspecies of A. cappadocica.

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Çetin Ilgaz

Karadeniz Technical University

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Kurtuluş Olgun

Adnan Menderes University

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Nazan Üzüm

Adnan Menderes University

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Emin Bozkurt

Adnan Menderes University

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Nikos Poulakakis

American Museum of Natural History

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Petros Lymberakis

American Museum of Natural History

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Paschalia Kapli

American Museum of Natural History

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Can Yilmaz

Adnan Menderes University

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