Phenotypic selection in common toad (Bufo bufo)

One of the most important problems for evolutionary biologists is to investigate the patterns and strength of phenotypic selection acting on quantitative traits in natural populations. Measurement of selection is complicated by the presence of correlations between characters; selection on a particular trait produces not only a direct effect, but indirect effects as well. Despite the growing body of phenotypic selection studies in a variety of taxa, studies on amphibians are still sparse. The aim of this study was to estimate patterns and strength of selection acting on a set of correlated characters in a natural population of Bufo bufo from the vicinity of Belgrade, Serbia. Morphological traits (body length, fore- and hind leg length) were measured, while fitness was assayed as fecundity and gonad weight for females and males, respec­tively. The regression approach was used to estimate selection differentials and gradients. Selection patterns differed between the sexes - linear selection differentials showed significant total directional selection for body size in females, but not in males. In males, differentials were significant for both fore- and hind leg lengths. Sample size did not permit identification of significant nonlinear (quadratic) selection.Jedan od najvažnijih problema za evolucione biologe je procena obrazaca i intenziteta fenotipske selekcije koja deluje na kvantitativne osobine u prirodnim populacijama. Procenu selekcije komplikuje i prisustvo korelacije između osobina; selekcija koja deluje na datu osobinu ima ne samo direktan efekat na tu osobinu, već i indirektan na raspodelu korelisanih osobina. Uprkos rastućoj količini informacija o fenotipskoj selekciji kod različitih taksona, studije na vodozemcima su još uvek vrlo retke. Cilj ovog rada bio je da se procene obrasci i intenzitet selekcije koja je delovala na skup korelisanih osobina u prirodnoj populaciji Bufo bufo iz okoline Beograda. Merene su morfološke osobine(dužina tela, dužina prednjih i zadnjih ekstremiteta); fitnes je procenjen preko fekunditeta kod ženki, odnosno težine gonada kod mužjaka. Regresioni metod je primenjen za procenu selekcionih diferencijala i gradijenata. Obrasci selekcije su se razlikovali među polovima - linearni selekcionih Diferencijali ukazuju na značajnu ukupnu direkcionu selekciju za veličinu tela kod ženki, ali ne i kod mužjaka. Kod mužjaka, diferencijali su bili značajni i za prednje i za zadnje ekstremitete. Zbog veličine uzorka nije bilo moguće naći značajnu nelinearnu(kvadratnu) selekciju.nul

Effect of climatic conditions on post-hibernation body condition and reproductive traits of Bufo bufo females

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Assessment of age and intersexual size differences in Bufo bufo

Numerous studies have underlined the complex nature of relationship between age, size, and reproductive traits in anurans. One of the most intriguing problems for evolutionary biologists is intersexual difference in body size (SSD). For testing various hypotheses about SSD, we need reliable estimates of its extent (the important issue being the choice of trait for analysis) as well as the accurate determination of individual age. The measures of SSD may be subject to error if estimated from populations with unknown age distribution; amphibians continue to grow throughout their life and SSD is linked to sex differences in traits such as age at maturity and lifespan. In the present paper, we analyze problems involved in accurate determination of age structure and factors that may lead to under- or overestimation of individual age, as well as the problem of appropriate choice of traits, in the light of our experience and results of investigating populations of common toad (Bufo bufo) in the vicinity of Belgrade.Brojne studije istakle su složenu prirodu odnosa između starosti, veličine tela i reproduktivnih osobina kod bezrepih vodozemaca. Za evolucione biologe jedan od najintrigantnijih problema je interseksualna razlika u veličini tela (SSD). Za testiranje hipoteza koje se tiču SSD, neophodne su tačne procene njene veličine (izuzetno je važno pitanje izbora osobina koje se koriste u toj analizi), kao i precizno određivanje starosti. Procena SSD može biti pogrešna ako nije poznata uzrasna struktura date populacije; vodozemci nastavljaju da rastu tokom života, a SSD je povezana sa interseksualnim razlikama u osobinama kao što su vreme polnog sazrevanja i dužina života. U ovom radu analiziramo probleme vezane za tačnu procenu uzrasne strukture i činioce koji mogu da dovedu do precenjenih ili potcenjenih vrednosti, kao i probleme adekvatnog izbora osobina za analizu, s obzirom na naša iskustva i rezultate proučavanja populacija Bufo bufo iz okoline Beograda.Projekat ministarstva br. 172

"It All Ended in an Unsporting Way": Serbian Football and the Disintegration of Yugoslavia, 1989-2006

Part of a wider examination into football during the collapse of Eastern European Communism between 1989 and 1991, this article studies the interplay between Serbian football and politics during the period of Yugoslavia's demise. Research utilizing interviews with individuals directly involved in the Serbian game, in conjunction with contemporary Yugoslav media sources, indicates that football played an important proactive role in the revival of Serbian nationalism. At the same time the Yugoslav conflict, twinned with a complex transition to a market economy, had disastrous consequences for football throughout the territories of the former Yugoslavia. In the years following the hostilities the Serbian game has suffered decline, major financial hardship and continuing terrace violence, resulting in widespread nostalgia for the pre-conflict era

Assessment of age and intersexual size differences in Bufo bufo

Numerous studies have underlined the complex nature of relationship between age, size, and reproductive traits in anurans. One of the most intriguing problems for evolutionary biologists is intersexual difference in body size (SSD). For testing various hypotheses about SSD, we need reliable estimates of its extent (the important issue being the choice of trait for analysis) as well as the accurate determination of individual age. The measures of SSD may be subject to error if estimated from populations with unknown age distribution; amphibians continue to grow throughout their life and SSD is linked to sex differences in traits such as age at maturity and lifespan. In the present paper, we analyze problems involved in accurate determination of age structure and factors that may lead to under- or overestimation of individual age, as well as the problem of appropriate choice of traits, in the light of our experience and results of investigating populations of common toad (Bufo bufo) in the vicinity of Belgrade.Brojne studije istakle su složenu prirodu odnosa između starosti, veličine tela i reproduktivnih osobina kod bezrepih vodozemaca. Za evolucione biologe jedan od najintrigantnijih problema je interseksualna razlika u veličini tela (SSD). Za testiranje hipoteza koje se tiču SSD, neophodne su tačne procene njene veličine (izuzetno je važno pitanje izbora osobina koje se koriste u toj analizi), kao i precizno određivanje starosti. Procena SSD može biti pogrešna ako nije poznata uzrasna struktura date populacije; vodozemci nastavljaju da rastu tokom života, a SSD je povezana sa interseksualnim razlikama u osobinama kao što su vreme polnog sazrevanja i dužina života. U ovom radu analiziramo probleme vezane za tačnu procenu uzrasne strukture i činioce koji mogu da dovedu do precenjenih ili potcenjenih vrednosti, kao i probleme adekvatnog izbora osobina za analizu, s obzirom na naša iskustva i rezultate proučavanja populacija Bufo bufo iz okoline Beograda.Projekat ministarstva br. 172

Activity patterns and habitat preference of eastern Hermann’s tortoise(Testudo hermanni boettgeri) in Serbia

We analyzed variation in the distribution of eastern Hermann’s tortoise (Testudo hermanni boettgeri) in a complex landscape consisting of both natural and human-altered habitats in a temperate climate region in Serbia. Our results indicated nonrandom distribution of tortoises within different habitat types with large and medium effect size for year and activity pattern, respectively. Additionally, the tortoises expressed relatively weak preference for habitats modified by human activity (e.g., vineyards, orchards, or gardens). The results suggested that these tortoises preferred some particular habitats more than others when performing specific activities. They also did not exhibit the same distribution pattern among habitats over consequent years. In other words, they were not randomly distributed among habitat types with regard to specific activity or year. The information on preferences in complex habitat systems is important for the conservation management of eastern Hermann’s tortoise and should be considered when planning activities related to sustainable development within the region of study

Evaluating taxonomic inflation: towards evidence-based species delimitation in Eurasian vipers (Serpentes: Viperinae)

International audienceThe designation of taxonomic units has important implications for the understanding and conservation ofbiodiversity. Eurasian vipers are a monophyletic group of viperid snakes (Serpentes, Viperinae), currently comprising fourgenera (Daboia, Macrovipera, Montivipera and Vipera) and up to 40 species. Taxonomic units have been described usinga wide variety of methods and criteria, and consequently, considerable controversy still surrounds the validity of somecurrently listed species. In order to promote a consensus- and evidence-based taxonomy of Eurasian vipers, we analysedpublished mitochondrial and nuclear DNA sequences for this group to reconstruct phylogenetic relationships among currentlyrecognized viper species.We also compiled information on external morphology to assess their morphological distinctiveness.Phylogenetic inference based on mtDNA sequences shows contrasting levels of divergence across genera and species andidentifies several instances of non-monophyly in described species. Nuclear DNA sequences show extremely low levels ofgenetic variation, with a widespread pattern of allele sharing among distant species, and even among genera. Revision ofmorphological data shows that most species designations rely on scalation traits that overlap extensively among species ofthe same genus. Based on our combined assessment, we recognize 15 taxa as valid species, three taxa which likely representspecies complexes, 17 taxa of doubtful validity as species, and five taxa for which species status is maintained but furtherresearch is highly recommended to assess taxonomic arrangements. We stress the need to implement integrative taxonomicapproaches for the recognition of evidence-based taxonomic units in Eurasian viper

Priority research needs to inform amphibian conservation in the Anthropocene

The problem of global amphibian declines has prompted extensive research over the last three decades. Initially, the focus was on identifying and characterizing the extent of the problem, but more recently efforts have shifted to evidence‐based research designed to identify best solutions and to improve conservation outcomes. Despite extensive accumulation of knowledge on amphibian declines, there remain knowledge gaps and disconnects between science and action that hamper our ability to advance conservation efforts. Using input from participants at the ninth World Congress of Herpetology, a U.S. Geological Survey Powell Center symposium, amphibian on‐line forums for discussion, the International Union for Conservation of Nature Assisted Reproductive Technologies and Gamete Biobanking group, and respondents to a survey, we developed a list of 25 priority research questions for amphibian conservation at this stage of the Anthropocene. We identified amphibian conservation research priorities while accounting for expected tradeoffs in geographic scope, costs, and the taxonomic breadth of research needs. We aimed to solicit views from individuals rather than organizations while acknowledging inequities in participation. Emerging research priorities (i.e., those under‐represented in recently published amphibian conservation literature) were identified, and included the effects of climate change, community‐level (rather than single species‐level) drivers of declines, methodological improvements for research and monitoring, genomics, and effects of land‐use change. Improved inclusion of under‐represented members of the amphibian conservation community was also identified as a priority. These research needs represent critical knowledge gaps for amphibian conservation although filling these gaps may not be necessary for many conservation actions

Effects of Environmental Disturbance on Phenotypic Variation: An Integrated Assessment of Canalization, Developmental Stability, Modularity, and Allometry in Lizard Head Shape

When populations experience suboptimal conditions, the mechanisms involved in the regulation of phenotypic variation can be challenged, resulting in increased phenotypic variance. This kind of disturbance can be diagnosed by using morphometric tools to study morphological patterns at different hierarchical levels and evaluate canalization, developmental stability, integration, modularity, and allometry. We assess the effect of urbanization on phenotypic variation in the common wall lizard (Podarcis muralis) by using geometric morphometrics to assess disturbance to head shape development. The head shapes of urban lizards were more variable and less symmetric, suggesting that urban living is more likely to disturb development. Head shape variation was congruent within and across individuals, which indicated that canalization and developmental stability are two related phenomena in these organisms. Furthermore, urban lizards exhibited smaller mean head sizes, divergent size-shape allometries, and increased deviation from within-group allometric lines. This suggests that mechanisms regulating head shape allometry may also be disrupted. The integrated evaluation of several measures of developmental instability at different hierarchical levels, which provided in this case congruent results, can be a powerful methodological guide for future studies, as it enhances the detection of environmental disturbances on phenotypic variation and aids biological interpretation of the results.Ministry of Education, Science, and Technological Development (MESTD) of the Republic of Serbia {[}173025]; Fundacao para a Ciencia e a Tecnologia (FCT; Portugal) {[}FCOMP-01-0124-FEDER-007062, PTDC/BIA-BEC/101256/2008]; project ``Biodiversity, Ecology, and Global Change{''}; North Portugal Regional Operational Programme (ON.2-O Novo Norte) under the National Strategic Reference Framework (NSRF) through the European Regional Development Fund (ERDF); FCT under Programa Operacional Potencial Humano-Quadro de Referencia Estrategico Nacional {[}SFRH/BPD/68493/2010]; European Social Fund; Portuguese Ministerio da Educacao e Ciencia; MESTD; FC