Abstract.-We propose a new method to estimate and correct for phylogenetic inertia in comparative data analysis. The method, called phylogenetic eigenvector regression (PVR) starts by performing a principal coordinate analysis on a pairwise phylogenetic distance matrix between species. Traits under analysis are regressed on eigenvectors retained by a broken-stick model in such a way that estimated values express phylogenetic trends in data and residuals express independent evolution of each species. This partitioning is similar to that realized by the spatial autoregressive method, but the method proposed here overcomes the problem of low statistical performance that occurs with autoregressive method when phylogenetic correlation is low or when sample size is too small to detect it. Also, PVR is easier to perform with large samples because it is based on well-known techniques of multivariate and regression analyses. We evaluated the performance of PVR and compared it with the autoregressive method using real datasets and simulations. A detailed worked example using body size evolution of Carnivora mammals indicated that phylogenetic inertia in this trait is elevated and similarly estimated by both methods. In this example, Type I error at a = 0.05 of PVR was equal to 0.048, but an increase in the number of eigenvectors used in the regression increases the error. Also, similarity between PVR and the autoregressive method, defined by correlation between their residuals, decreased by overestimating the number of eigenvalues necessary to express the phylogenetic distance matrix. To evaluate the influence of c1adogram topology on the distribution of eigenvalues extracted from the double-centered phylogenetic distance matrix, we analyzed 100 randomly generated c1adograms (up to 100 species). Multiple linear regression of log transformed variables indicated that the number of eigenvalues extracted by the broken-stick model can be fully explained by c1adogram topology. Therefore, the broken-stick model is an adequate criterion for determining the correct number of eigenvectors to be used by PVR. We also simulated distinct levels of phylogenetic inertia by producing a trend across 10, 25, and 50 species arranged in "comblike" c1adograms and then adding random vectors with increased residual variances around this trend. In doing so, we provide an evaluation of the performance of both methods with data generated under different evolutionary models than tested previously. The results showed that both PVR and autoregressive method are efficient in detecting inertia in data when sample size is relatively high (more than 25 species) and when phylogenetic inertia is high. However, PVR is more efficient at smaller sample sizes and when level of phylogenetic inertia is low. These conclusions were also supported by the analysis of 10 real datasets regarding body size evolution in different animal clades. We concluded that PVR can be a useful alternative to an autoregressive method in comparative data analysis.

We propose a new method to estimate and correct for phylogenetic inertia in comparative data analysis. The method, called phylogenetic eigenvector regression (PVR) starts by performing a principal coordinate analysis on a pairwise phylogenetic distance matrix between species. Traits under analysis are regressed on eigenvectors retained by a broken-stick model in such a way that estimated values express phylogenetic trends in data and residuals express independent evolution of each species. This partitioning is similar to that realized by the spatial autoregressive method, but the method proposed here overcomes the problem of low statistical performance that occurs with autoregressive method when phylogenetic correlation is low or when sample size is too small to detect it. Also, PVR is easier to perform with large samples because it is based on well-known techniques of multivariate and regression analyses. We evaluated the performance of PVR and compared it with the autoregressive method using real datasets and simulations. A detailed worked example using body size evolution of Carnivora mammals indicated that phylogenetic inertia in this trait is elevated and similarly estimated by both methods. In this example, Type I error at a = 0.05 of PVR was equal to 0.048, but an increase in the number of eigenvectors used in the regression increases the error. Also, similarity between PVR and the autoregressive method, defined by correlation between their residuals, decreased by overestimating the number of eigenvalues necessary to express the phylogenetic distance matrix. To evaluate the influence of c1adogram topology on the distribution of eigenvalues extracted from the double-centered phylogenetic distance matrix, we analyzed 100 randomly generated c1adograms (up to 100 species). Multiple linear regression of log transformed variables indicated that the number of eigenvalues extracted by the broken-stick model can be fully explained by c1adogram topology. Therefore, the broken-stick model is an adequate criterion for determining the correct number of eigenvectors to be used by PVR. We also simulated distinct levels of phylogenetic inertia by producing a trend across 10, 25, and 50 species arranged in "comblike" c1adograms and then adding random vectors with increased residual variances around this trend. In doing so, we provide an evaluation of the performance of both methods with data generated under different evolutionary models than tested previously. The results showed that both PVR and autoregressive method are efficient in detecting inertia in data when sample size is relatively high (more than 25 species) and when phylogenetic inertia is high. However, PVR is more efficient at smaller sample sizes and when level of phylogenetic inertia is low. These conclusions were also supported by the analysis of 10 real datasets regarding body size evolution in different animal clades. We concluded that PVR can be a useful alternative to an autoregressive method in comparative data analysis.

In this paper, we used geostatistical approaches to describe bi‐dimensional spatial patterns in species richness of South American birds of prey (Falconiformes and Strigiformes). They indicated strong spatial patterns both across latitude and longitude, for the two groups. These patterns were then correlated with those expected by a bi‐dimensional null model constructed to take into account South America continental edges. As considerable departures from the null model were observed, there may be other ecological or evolutionary explanations for spatial patterns in species richness. Variation seems to be related to habitat heterogeneity across the continent, especially when considering differences between habitats in the central and south‐eastern portion of the continent and in the Andean region. This supports previous conclusions that habitat type and heterogeneity affect species richness and abundance at different spatial scales.

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O presente estudo objetivou realizar o monitoramento do córrego Cascavel, localizado em Goiânia, através de análises físico-químicas e microbiológicas da água de superfície. Foram selecionados quatro pontos, a partir dos quais as amostras foram coletadas, no período de março a setembro de 2006. Foram identificadas diversas fontes poluidoras para o córrego, dentre as quais se destacam a exploração desordenada do solo e a presença de esgotos domésticos, apontados como responsáveis pelos níveis elevados de matéria orgânica e coliformes, indicadores de contaminação de origem fecal na água, considerando-se os parâmetros de corpos d’água classe 2 presentes na Resolução CONAMA nº 357/2005.

During the last few years, many models have been proposed to link microevolutionary processes to macroevolutionary patterns, defined by comparative data analysis. Among these, Brownian motion and Ornstein-Uhlenbeck (O-U) processes have been used to model, respectively, genetic drift or directional selection and stabilizing selection. These models produce different curves of pairwise variance between species against time since divergence, in such a way that different profiles appear in phylogenetic correlograms. We analyzed variation in body length among 19 species of South American owls, by means of phylogenetic correlograms constructed using Moran's I coefficient in four distance classes. Phylogeny among species was based on DNA hybridization. The observed correlogram was then compared with 500 correlograms obtained by simulations of Brownian motion and O-U over the same phylogeny, using discriminant analysis. The observed correlogram indicates a phylogenetic gradient up to 45 mya, when coefficients tend to stabilize, and it is similar to the correlograms produced by the O-U process. This is expected when we consider that body size of organisms is correlated with many ecological and life-history traits and subjected to many constraints that can be modeled by the O-U process, which has been used to describe evolution under stabilizing selection.

Knowledge of different groups of zooplankton has been a powerful tool for assessing changes in aquatic ecosystems caused by various impactful activities such as introduction of exotic species, siltation and contamination by domestic and industrial waste water, deforestation and others. This study aimed to evaluate the water quality and detect the effects of a lotic environment of this community. The samples were collected during the period from April to September 2006. Water samples for qualitative and quantitative analysis of zooplankton were collected by vertical hauls the entire water column, using -If a cylinder-conical net of 35 mm mesh width. Samples were collected in the stream Cascavel in Goiânia, Goiás. The analysis of the zooplankton community stream Cascavel revealed the presence of several groups in the body of water. The study also showed the importance of these living things in water quality and its relationship to the physical and chemical factors. KEYWORDS: water quality, zooplancton, cascavel stream ZOOPLANCTON COMO INDICADOR DE POLUIÇÃO NO CORREGO CASCAVEL,GOIÂNIA, GOIÁS RESUMO O conhecimento dos diferentes grupos de zooplâncton tem sido um poderoso instrumento para avaliar modificações causadas nos ecossistemas aquáticos por várias atividades impactantes como introdução de espécies exóticas, assoreamento e contaminação por esgotos domésticos e industriais, desmatamento entre outras. O presente estudo teve por objetivo avaliar a qualidade da água e detectar os efeitos de um ambiente lótico sobre esta comunidade. As amostras foram coletadas durante o período de abril a setembro de 2006. As amostras de água para a análise quali-quantitativa do zooplâncton foram coletadas por meio de arrastos verticais Rev. TREE DIMENSIONAL, ProFloresta -Goiânia, v.1 n.2; p. 2016 80 de toda coluna d'água, utilizando -se uma rede cilindro-cônica de 35 mm de abertura de malha. As coletas foram realizadas no córrego Cascavel em Goiânia, Goiás. A análise da comunidade zooplanctônica do córrego Cascavel revelou a presença de vários grupos no corpo d'água. O estudo mostrou também a importância destes seres vivos na qualidade da água e a sua relação com os fatores físico-químicos. PALAVRAS-CHAVE: zooplancton, córrego cascavel, qualidade da água.