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BACKGROUND AND AIMS: Diversity in pappus shapes and size in Asteraceae suggests an adaptive response to dispersion challenges adjusting diaspore to optimal phenotypic configurations. Here, by analysing the relationship among pappus-cypsela size relationships, flight performance and pappus types in an evolutionary context, we evaluate the role of natural selection acting on the evolution of diaspore configuration at a macro-ecological scale in the daisy family. METHODS: To link pappus-cypsela size relationships with flight performance we collected published data on these traits from 82 species. This allowed us to translate morphometric traits in flight performance for 150 species represented in a fully resolved backbone phylogeny of the daisy family. Through ancestral reconstructions and evolutionary model selection we assessed whether flight performance was associated with and constrained by different pappus types. Additionally, we evaluated, through phylogenetic regressions, whether species with different pappus types exhibited evolutionary allometric pappus-cypsela size relationships. RESULTS: The setose pappus type had the highest flight performances and represented the most probable ancestral state in the family. Stepwise changes in pappus types independently led from setose to multiple instances of pappus loss with associated reduction in flight performance. Flight performance evolution was best modelled as constrained by five adaptive regimes represented by specific pappus types which correspond with specific optimal diaspore configurations that are distinct in pappus-cypsela allometric relationships. CONCLUSIONS: Evolutionary modelling suggests natural selection as the main factor of diaspore configuration changes which proceeded towards five optima, often overcoming constraints imposed by allometric relationships and favouring evolution in certain directions. With the perspective that natural selection is the main process driving the observed patterns, various biotic and abiotic are suggested as principal drivers of transitions in diaspore configurations along space and time in the daisy family history. Results also allow discussion of evolutionary changes in a historical context.

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We assess the Tropical Niche Conservatism Hypothesis in the genus Escallonia in South America using phylogeny, paleoclimate estimation and current niche modelling. We tested four predictions: (1) the climatic condition where the ancestor of Escallonia grew is megathermal; (2) the temperate niche is a derived condition from tropical clades; (3) the most closely related species have a similar current climate niche (conservation of the phylogenetic niche); and (4) there is a range expansion from the northern Andes to high latitudes during warm times. Our phylogenetic hypothesis shows that Escallonia originated 52.17 ± 0.85 My, in the early Eocene, with an annual mean temperature of 13.8 °C and annual precipitation of 1081 mm, corresponding to a microthermal to mesothermal climate; the species of the northern and central tropical Andes would be the ancestral ones, and the temperate species evolved between 32 and 20 My in a microthermal climate. The predominant evolutionary models were Brownian and Ornstein-Uhlenbeck. There was phylogenetic signal in 7 of the 9 variables, indicating conservation of the climatic niche. Escallonia would have originated in the central and southern Andes and reached the other environments by dispersion.

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Introduction: Body size is an essential trait for endotherms to face the physiological requirements of cold, so there is a tendency to large body size at high altitudes and latitudes, known as Bergmann's rule. However, the validity of this ecomorphological rule to small-bodied endotherms across altitudinal gradients is poorly known. Objective: To understand the effects of environmental variation on body size, we assessed whether interspecific variation in body size of small tropical endotherms follows Bergmann's rule along tropical altitudinal gradients. Methods: We compiled data on elevational ranges and body masses for 133 species of hummingbirds of Colombia. We then assessed the association between body mass and mid-point of the altitudinal distribution using phylogenetic generalized least squares (PGLS) analyses under different evolutionary models. Results: We found a decelerating rate of evolution for body size since the Early Burst model of evolution provided a better fit to body mass data. For elevational range, we found a slow and constant rate since Pagel's lambda model provided a better fit to the mid-point of the altitudinal distribution data. Besides, phylogenetic regression analysis indicated that body mass and the altitudinal range of hummingbirds are associated through the phylogeny, with a positive but slight association (R2= 0.036). Conclusions: We found that body mass and altitude of hummingbirds are positively related, which is in agreement with expectations under Bergmann's rule. However, this association was weaker than expected for small and non-passerine birds like hummingbirds. Thus, our results suggest that environmental changes across altitudinal gradients do not strongly influence body mass in small tropical endotherms as hummingbirds.

Introducción: El tamaño corporal es un rasgo importante para determinar la respuesta de los endotermos a los requerimientos que exigen las zonas frías, por lo cual se espera una tendencia hacia el incremento del tamaño corporal al aumentar la altitud y la latitud. Sin embargo, se conoce poco acerca de la validez de esta regla ecomorfológica, conocida como la regla de Bergmann, para endotermos pequeños en gradientes altitudinales tropicales. Objetivo: Con el fin de entender los efectos de la variación ambiental sobre el tamaño corporal, se evaluó sí la variación interespecífica en la masa corporal de endotermos tropicales pequeños se ajusta a la regla de Bergmann a lo largo de gradientes de elevación. Métodos: Se compilaron datos sobre los rangos de distribución altitudinal y los tamaños corporales de 133 especies de colibríes en Colombia. Posteriormente, se evaluó la asociación entre la masa corporal y el punto medio de distribución altitudinal de los colibríes mediante análisis de mínimos cuadrados generalizados filogenéticos (PGLS) bajo diferentes modelos evolutivos. Resultados: La evolución de la masa corporal se ajustó mejor a un modelo de evolución Early Burst, mientras que el rango de elevación al modelo evolutivo lambda de Pagel; lo que indica que la tasa de evolución es desacelerada para el tamaño del cuerpo, mientras es lenta y constante para el rango de elevación. Además, el análisis de regresión filogenética indica que la masa corporal y el rango de elevación están positiva y ligeramente asociados (R2 = 0.036). Conclusiones: De acuerdo con lo esperado por la regla de Bergmann, los resultados indican que los colibríes tienden a ser más grandes a mayores altitudes. Sin embargo, esta asociación es más débil de lo esperado para aves no paseriformes de tamaño pequeño como los colibríes.Por lo tanto, los resultados sugieren que las variaciones ambientales a lo largo de gradientes de elevación no tienen una influencia fuerte sobre el tamaño corporal de endotermos pequeños como los colibríes.

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Papaya (Carica papaya L.) is one of the main tropical fruits consumed in Brazil. The country is also one of the main papaya exporters, but one of the factors hindering its production lies on foliar diseases such as papaya black spot, which is caused by fungus Asperisporium caricae. This pathogen is widely distributed in the main producing regions of the Brazilian coastal area. Phylogeographic studies contribute to the knowledge about the genetic diversity and geographical distribution of genealogical lineages (haplotypes) and help better understanding the reproductive and evolutionary processes of closely related species or of a single species. Such information is useful in studies about phytopathogenic fungi because it enables identifying the most prevalent genealogical lineages in a given location, as well as inferring dispersal routes and providing information on the origin and frequency of exotic material introduction events. Results in this type of study can significantly help developing new disease control strategies. Literature still lacks studies on the Papaya x A. caricae pathosystem. Based on the phylogenetic and phylogeographic analysis applied to nucleotide sequences of the Internal transcribed spacer (ITS) gene, we herein address the genealogical and dispersal events recorded for this pathogen in order to better understand its evolution in, and adaptation to, Brazilian orchards. Three haplotypes were identified among the A. caricae isolates; their distribution was mostly related to the geographic distance between sample collection regions rather than to any reproductive or evolutionary processes presented by the species. The low variability among the herein studied isolates may result from the physiological specialization (survival exclusively associated with the host plant) and from the regional transport of contaminated fruits (with lesions and spores), besides the low contribution of reproductive events, which corroborate the lack of knowledge about the sexual stages of A. caricae.

O mamoeiro (Carica papaya L.), é uma das principais frutas tropicais consumidas no Brasil. O país é um dos principais exportadores de mamão e um dos gargalos da produção mundial está diretamente ligado à ocorrência de doenças foliares, podendo-se destacar a pinta-preta do mamoeiro, causada pelo fungo Asperisporium caricae. O patógeno está amplamente distribuído nas principais regiões produtoras, as quais englobam grande parte do litoral Brasileiro. Estudos filogeográficos contribuem não só para oconhecimento da diversidade genética e da distribuição geográfica das linhagens genealógicas (haplótipos), como também contribuem para o conhecimento dos processos reprodutivos e evolutivos de uma espécie ou de espécies estreitamente relacionadas. No estudo de fungos fitopatogênicos, tais informações são úteis para identificar linhagens genealógicas mais prevalentes em um determinado local, inferir as rotas de dispersão e fornecer informações sobre a origem e frequência dos eventos de introdução de material exótico. Este tipo de estudo produz resultados que podem colaborar significativamente na elaboração de novas estratégias de controle da doença. Não existe, até o presente momento, este tipo de estudo para o patossistema Mamoeiro x A. caricae. Neste trabalho, por meio da análise filogenética e filogeográfica, a partir de sequências nucleotídicas do gene Internal transcribed spacer (ITS), discutimos os eventos genealógicos e de dispersão deste patógeno com o intuito de compreender melhor sua evolução e adaptação nos pomares brasileiros. Dentre os isolados de A. caricae foram identificados 3 haplótipos, sendo sua distribuição relacionada mais ao distanciamento geográfico das regiões das coletas das amostras do que a eventuais processos reprodutivos ou evolutivos da espécie. Acredita-se que a baixa variabilidade dentre os isolados estudados seja explicada pela especialização fisiológica (sobrevivência exclusivamente associada à planta hospedeira) e ao transporte regional de frutos contaminados (com lesões e esporos), sendo baixa a contribuição de eventos reprodutivos, o que corrobora o desconhecimento de fase sexual de A. caricae.

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Understanding how the climatic niche of species evolved has been a topic of high interest in current theoretical and applied macroecological studies. However, little is known regarding how species traits might influence climatic niche evolution. Here, we evaluated patterns of climatic niche evolution in turtles (tortoises and freshwater turtles) and whether species habitat (terrestrial or aquatic) influences these patterns. We used phylogenetic, climatic and distribution data for 261 species to estimate their climatic niches. Then, we compared whether niche overlap between sister species was higher than between random species pairs and evaluated whether niche optima and rates varied between aquatic and terrestrial species. Sister species had higher values of niche overlap than random species pairs, suggesting phylogenetic climatic niche conservatism in turtles. The climatic niche evolution of the group followed an Ornstein-Uhlenbeck model with different optimum values for aquatic and terrestrial species, but we did not find consistent evidence of differences in their rates of climatic niche evolution. We conclude that phylogenetic climatic niche conservatism occurs among turtle species. Furthermore, terrestrial and aquatic species occupy different climatic niches but these seem to have evolved at similar evolutionary rates, reinforcing the importance of habitat in understanding species climatic niches and their evolution.

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Abstract: Fishes exhibit the greatest diversity of species among vertebrates, offering a number of relevant models for genetic and evolutionary studies. The investigation of sex chromosome differentiation is a very active and striking research area of fish cytogenetics, as fishes represent one of the most vital model groups. Neotropical fish species show an amazing variety of sex chromosome systems, where different stages of differentiation can be found, ranging from homomorphic to highly differentiated sex chromosomes. Here, we draw attention on the impact of recent developments in molecular cytogenetic analyses that helped to elucidate many unknown questions about fish sex chromosome evolution, using excellent characiform models occurring in the Neotropical region, namely the Erythrinidae family and the Triportheus genus. While in Erythrinidae distinct XY and/or multiple XY-derived sex chromosome systems have independently evolved at least four different times, representatives of Triportheus show an opposite scenario, i.e., highly conserved ZZ/ZW system with a monophyletic origin. In both cases, recent molecular approaches, such as mapping of repetitive DNA classes, comparative genomic hybridization (CGH), and whole chromosome painting (WCP), allowed us to unmask several new features linked to the molecular composition and differentiation processes of sex chromosomes in fishes.

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Evolutionary radiations on continents are less well-understood and appreciated than those occurring on islands. The extent of ecological influence on species divergence can be evaluated to determine whether a radiation was ultimately the outcome of divergent natural selection or else arose mainly by nonecological divergence. Here, we used phylogenetic comparative methods to test distinct hypotheses corresponding to adaptive and nonadaptive evolutionary scenarios for the morphological evolution of sigmodontine rodents. Results showed that ecological variables (diet and life-mode) explain little of the shape and size variation of sigmodontine skulls and mandibles. A Brownian model with varying rates for insectivory versus all other diets was the most likely evolutionary model. The insectivorous sigmodontines have a faster rate of morphological evolution than mice feeding on other diets, possibly due to stronger selection for features that aid insectivory. We also demonstrate that rapid early-lineage diversification is not accompanied by high morphological divergence among subclades, contrasting with island results. The geographic size of continents permits spatial segregation to a greater extent than on islands, allowing for allopatric distributions and escape from interspecific competition. We suggest that continental radiations of rodents are likely to produce a pattern of high species diversification coupled with a low degree of phenotypic specialization.

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Background: Phylogenetic analyses are an essential part in the exploratory assessment of nucleic acid and amino acid sequences. Particularly in virology, they are able to delineate the evolution and epidemiology of disease etiologic agents and/or the evolutionary path of their hosts. The objective of this review is to help researchers who want to use phylogenetic analyses as a tool in virology and molecular epidemiology studies, presenting the most commonly used methodologies, describing the importance of the different techniques, their peculiar vocabulary and some examples of their use in virology. Review: This article starts presenting basic concepts of molecular epidemiology and molecular evolution, emphasizing their relevance in the context of viral infectious diseases. It presents a session on the vocabulary relevant to the subject, bringing readers to a minimum level of knowledge needed throughout this literature review. Within its main subject, the text explains what a molecular phylogenetic analysis is, starting from a multiple alignment of nucleotide or amino acid sequences. The different software used to perform multiple alignments may apply different algorithms. To build a phylogeny based on amino acid or nucleotide sequences it is necessary to produce a data matrix based on a model for nucleotide or amino acid replacement, also called evolutionary model. [...]

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Background: Phylogenetic analyses are an essential part in the exploratory assessment of nucleic acid and amino acid sequences. Particularly in virology, they are able to delineate the evolution and epidemiology of disease etiologic agents and/or the evolutionary path of their hosts. The objective of this review is to help researchers who want to use phylogenetic analyses as a tool in virology and molecular epidemiology studies, presenting the most commonly used methodologies, describing the importance of the different techniques, their peculiar vocabulary and some examples of their use in virology. Review: This article starts presenting basic concepts of molecular epidemiology and molecular evolution, emphasizing their relevance in the context of viral infectious diseases. It presents a session on the vocabulary relevant to the subject, bringing readers to a minimum level of knowledge needed throughout this literature review. Within its main subject, the text explains what a molecular phylogenetic analysis is, starting from a multiple alignment of nucleotide or amino acid sequences. The different software used to perform multiple alignments may apply different algorithms. To build a phylogeny based on amino acid or nucleotide sequences it is necessary to produce a data matrix based on a model for nucleotide or amino acid replacement, also called evolutionary model. [...](AU)

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Eigenfunction analyses have been widely used to model patterns of autocorrelation in time, space and phylogeny. In a phylogenetic context, Diniz-Filho et al. (1998) proposed what they called Phylogenetic Eigenvector Regression (PVR), in which pairwise phylogenetic distances among species are submitted to a Principal Coordinate Analysis, and eigenvectors are then used as explanatory variables in regression, correlation or ANOVAs. More recently, a new approach called Phylogenetic Eigenvector Mapping (PEM) was proposed, with the main advantage of explicitly incorporating a model-based warping in phylogenetic distance in which an Ornstein-Uhlenbeck (O-U) process is fitted to data before eigenvector extraction. Here we compared PVR and PEM in respect to estimated phylogenetic signal, correlated evolution under alternative evolutionary models and phylogenetic imputation, using simulated data. Despite similarity between the two approaches, PEM has a slightly higher prediction ability and is more general than the original PVR. Even so, in a conceptual sense, PEM may provide a technique in the best of both worlds, combining the flexibility of data-driven and empirical eigenfunction analyses and the sounding insights provided by evolutionary models well known in comparative analyses.