Papers by Fernanda Cassemiro
South American freshwater fish diversity shaped by Andean uplift since the Late Cretaceous&#160
<p><strong>South America is home to the highest fresh... more <p><strong>South America is home to the highest freshwater fish biodiversity on Earth.</strong><strong> The hotspot of species richness is located in the western Amazon Basin, and richness decreases downstream along the Amazon River towards the mouth at the Atlantic coast</strong><strong>. This pattern contradicts the commonly observed positive relationship between stream size and biodiversity in river systems across the world</strong><strong>. We investigate the role of river capture events caused by Andean mountain building and repeated episodes of flooding in western Amazonia in shaping the modern-day richness pattern of freshwater fishes in South America. To this end, we combine a reconstruction of river networks since 80 million years ago with a model simulating dispersal, allopatric speciation and extinction over the dynamic landscape of rivers and lakes. We show that Andean mountain building and consequent numerous small river capture events in western Amazonia caused freshwater habitats to be highly dynamic, leading to high diversification rates and exceptional richness. The history of marine incursions and lakes, including the Miocene Pebas megawetland system in western Amazonia, played a secondary role. This study is a major step towards the understanding of the processes involved in the interactions between the solid Earth, landscapes, and life of extraordinary biodiverse South America.</strong></p>
Oecologia Australis, Jun 30, 2010
Há um contínuo debate na literatura ecológica sobre os mecanismos que determinam os padrões espac... more Há um contínuo debate na literatura ecológica sobre os mecanismos que determinam os padrões espaciais da riqueza de espécies. Uma das tentativas de encontrar explicações para esses padrões é a Teoria Metabólica da Ecologia (MTE-Metabolic Theory of Ecology). A MTE assume que os padrões de distribuição de espécies estão relacionados à temperatura e que esta interfere no metabolismo dos indivíduos. Neste trabalho, mostraremos que, embora controversa em vários aspectos, a MTE difere das demais hipóteses desenvolvidas para explicar os gradientes de riqueza por fazer predições precisas em relação aos padrões de riqueza de espécies em ampla escala e propõe que uma variável ambiental influencia primariamente esses padrões (temperatura). Essas predições tornam a teoria testável e falseável, o que tem tornado a MTE alvo de constantes debates na ecologia nos últimos anos. Desta forma, neste artigo analisaremos a repercussão da MTE na literatura científica através de análises cienciométricas, descreveremos os princípios básicos dessa teoria e apontaremos suas principais vantagens e falhas ao tentar explicar os padrões latitudinais de riqueza de espécies. Apesar da MTE muito citada nos principais periódicos sobre ecologia, ela não se aplica à maioria dos processos ecológicos, pois não leva em consideração fatores fundamentais que, geralmente, regem os padrões de diversidade. Palavras-chave: Riqueza de espécies; cienciometria; gradiente de temperatura; taxa metabólica; macroecologia. ABSTRACT DIVERSITY GRADIENTS AND THE METABOLIC THEORY OF ECOLOGY. There is an ongoing debate about the mechanisms involved in the origin and maintenance of geographical patterns in species richness. An attempt to explain these patterns is the Metabolic Theory of Ecology (MTE) was proposed. The MTE assumes that species richness patterns are related to environmental temperature, which influences on individual metabolism. In this paper, we show that although controversial in some aspects, the MTE differs from other theories by making precise predictions about species richness patterns in large spatial scale and proposing that an environmental variable (temperature) influences these patterns. These predictions make the theory testable and falsifiable, which has caused a considerable debate in Ecology in the last years. Thus, here we analyze the MTE impact on the scientific literature, via a scientometric analyses, as well as describing the basic principles of this theory and point out their main advantages and disadvantages. Although MTE has being highly cited by main ecology journals, it does not apply to most of ecological processes, because it does not consider fundamental features that, in general, drive the diversity patterns.
Global Ecology and Biogeography, Jul 14, 2021
Aim: We aimed to dissect the spatial variation of the direct and indirect effects of climate and ... more Aim: We aimed to dissect the spatial variation of the direct and indirect effects of climate and productivity on global species richness of terrestrial tetrapods. Location: Global. Time period: Present. Major taxa studied: Terrestrial tetrapods. Methods: We used a geographically weighted path analysis to estimate and map the direct and indirect effects of temperature, precipitation and primary productivity on species richness of terrestrial tetrapods across the globe. Results: We found that all relationships shift in magnitude, and even in direction, among taxonomic groups, geographical regions and connecting paths. Direct effects of temperature and precipitation are generally stronger than both indirect effects mediated by productivity and direct effects of productivity. Main conclusions: Richness gradients seem to be driven primarily by effects of climate on organismal physiological limits and metabolic rates rather than by the amount of productive energy. Reptiles have the most distinct relationships across tetrapods, with a clear latitudinal pattern in the importance of temperature versus water.
Ecography, Aug 3, 2012
Attempts to explain the origin of species diversity gradients often lack generality across geogra... more Attempts to explain the origin of species diversity gradients often lack generality across geographic regions or taxa. One possible reason for this is that species respond diff erently to the same environmental descriptors (e.g. climate) across geographical space, i.e. the diversity-environment relationship is spatially nonstationary. Here we evaluate the spatial nonstationarity of the relationships between amphibian species richness and variables representing three primary climatic hypotheses: historical climate variability, seasonality and productivity. We formulated nonstationary explicit predictions for the taxon based on its ecophysiological attributes. We employed two global approaches that assume stationarity-standard non-spatial OLS regression and spatial eigenvector mapping (SEVM)-and compared them with a nonstationary partial GWR (Geographically Weighted Regression), which allows the investigation of the relative contributions of each predictor regionally, helping to portray large-scale patterns. Although productivity was a better correlate to species richness than the other factors in both global and local approaches, no single hypothesis fully explained the worldwide pattern of species richness. Spatial nonstationarity was present in all relationships, and substantial fractions of the variation in the data were unexplained due to collinearity. We discuss some noteworthy regional cases and propose that the history of exposure to specifi c environmental conditions is responsible for geographical diff erences in the amphibian-climate relationships, as stated by the niche conservatism hypothesis. Finally, we argue that there is a trade-off in the selection of the spatial scale analysed-regional vs global-regarding the generality vs the explanatory power of the resulting pattern of species richness.
Spatially explicit paleoclimate reconstruction of South America for the last 800 thousand years
For each 500-year time interval from 800 Ka (years ago) to the present (1600 time steps), we used... more For each 500-year time interval from 800 Ka (years ago) to the present (1600 time steps), we used a paleoclimate model to assign to each of the 4820 map cells an estimate of the mean temperature of the warmest and coolest quarters and the mean daily precipitation of the wettest and driest quarters. These four factors, on two environmental axes (annual temperature and annual precipitation) characterize the changing climate in each grid cell over the time-course of the simulation.The database consists of the paleoclimate data used in this simulation. It is composed of one text file for each climate variable: (1) minimum annual precipitation, (2) maximum annual precipitation, (3) minimum annual temperature, and (4) maximum annual temperature. Within each file, each row represents a single map cell (4820 in total). The first two columns are the geographical coordinates of each grid cell (latitude and longitude in decimal degrees). The succeeding columns describe the climate variable at each time slice of the series, at successive 500-year intervals. Each column is labeled Tx, where x is thousands of years before present. For example, column "T795.5" of file "PrecipAvgAnnualMax.txt" contains the map cell data for maximum annual precipitation at 795.5kya.
Deviations from predictions of the metabolic theory of ecology can be explained by violations of assumptions
Ecology, Dec 1, 2010
The metabolic theory of ecology (MTE) is based on models derived from the first principles of the... more The metabolic theory of ecology (MTE) is based on models derived from the first principles of thermodynamics and biochemical kinetics. The MTE predicts that the relationship between temperature and species richness of ectotherms should show a specific slope. Testing the validity of this model, however, depends on whether empirical data do not violate assumptions and are obtained within contour conditions. When dealing with richness gradients, the MTE must be empirically tested only for ectothermic organisms at high organization levels and when their body size as well as abundance does not vary with temperature gradients. Here we evaluate whether the magnitude of the deviations in slope expected from the MTE to empirical data for New World amphibians is due to the violations of model assumptions and to lack of generality due to restricting contour conditions. We found that the MTE correctly predicted biodiversity patterns only at higher levels of organization and when assumptions of the basic model were not violated. Approximately 60% of the deviations from the MTE‐predicted slope across amphibian families were due to violations of the model assumptions. The hypothesis that richness patterns are a function of environmental temperature is too restrictive and does not take complex environmental and ecological processes into account. However, our results suggest that it may be possible to obtain multiple derivations of the MTE equation if idiosyncrasies in spatial and biological/ecological issues that are essential to understanding biodiversity patterns are considered.
Ecology of Freshwater Fish, Mar 1, 2008
This study aims to analyse whether Satanoperca pappaterra changes its feeding habit throughout on... more This study aims to analyse whether Satanoperca pappaterra changes its feeding habit throughout ontogenetic development, and whether morphological ontogenetic patterns are related to its feeding habit and food capture. We collected 258 individuals in the Cuiabá river basin (Brazil) for analyses. There was a weak relationship between diet and body size, as evidenced by size class and multivariate analyses, and niche breadth did not vary strongly during ontogenetic development. Eight morphometric variables were measured in each individual. We found an isometric relationship for mouth height and width, and for head length. We found positive allometry for snout length and body height in relation to body length, whereas this relationship for intestine length and eye diameter showed negative allometry. These results suggest that morphology and consequently diet vary weakly during ontogenetic development of S. pappaterra.
Hydrobiologia, Dec 20, 2017
The invasion of tilapia can result in substantial impacts on native communities. Thus, understand... more The invasion of tilapia can result in substantial impacts on native communities. Thus, understanding the spatial dynamics of invasions may help prevent future introductions and mitigate impacts. This study estimated the environmentally suitable areas for occurrence of eight tilapia species (genera Coptodon, Oreochromis, Pelmatolapia, and Sarotherodon) in the Americas and their invasive potential using Ecological Niche Models (ENMs). The United States is the most invaded country, receiving all tilapia species. In South America, the southeast and south regions of Brazil are highlighted as the areas where two species are concentrated. The ENMs predicted that all tilapia species have high invasive potential in the Americas, and despite having more tilapias in North America, South and Central Americas are more susceptible to tilapia invasion. All South American basins were predicted to harbor tilapia species that have not yet arrived on the subcontinent. Our study evidences the need to implement management measures and governmental policies in the Americas to deal with problems caused by tilapia introductions. In North America, the focus is on the control of tilapia populations and in Central and South America priority should be given to contention of introduction processes.
Research Square (Research Square), Jan 12, 2021
A primary goal of biodiversity research is to uncover the processes acting in space and time to c... more A primary goal of biodiversity research is to uncover the processes acting in space and time to create the global distribution of species richness. However, we currently lack an understanding of how recent versus ancient biodiversity dynamics shape patterns of diversity for most groups. Here, we introduce a method to partition lineage turnover into recent and ancestral components, and use it to identify hotspots of turnover at the global scale for 8,296 bird species. Counter to the tropical niche conservatism hypothesis, we find extra-tropical regions such as Greenland and the Sahara are hotspots of ancestral turnover, while areas with high climatic variation such as (sub)tropical mountains and biome transitions are recent turnover hotspots. We can now quantify the relative contribution of contemporary and ancient lineage dynamics to assemblage structure, which
Oecologia Australis, 2008
Nesse trabalho exploramos os aspectos teóricos da Teoria Neutra da Biodiversidade e Biogeografi a... more Nesse trabalho exploramos os aspectos teóricos da Teoria Neutra da Biodiversidade e Biogeografi a (TNB) proposta por Hubbell (2001), apresentando juntamente um estudo cienciométrico sobre o impacto dessa teoria na comunidade científi ca, seus avanços, principais críticas e algumas perspectivas. A TNB pode facilitar o desenvolvimento de hipóteses nulas testáveis principalmente em comunidades nas quais características espaciais explícitas desempenham um papel marcante, representando uma importante ferramenta conceitual e analítica. A premissa mais provocativa da TNB é que os organismos de todas as espécies têm propriedades ecológicas idênticas. Isso choca com a visão clássica de organização das comunidades por nicho ecológico e até mesmo com a teoria da evolução pela seleção natural. O livro no qual Hubbell apresentou a TNB teve (e ainda tem) grande repercussão na literatura científi ca. Até os dias atuais, essa publicação foi citada por 1.128 artigos, em 239 periódicos científi cos, classifi cados em 21 diferentes categorias de assuntos diferentes. Apesar do impacto em diferentes áreas do conhecimento, Hubbell (2001) foi mais discutido entre ecólogos e biólogos da conservação. As críticas contra a TNB são abundantes, principalmente acerca de seu principal axioma (a equivalência ecológica das espécies). A despeito das críticas, e do fato de que TNB tenha sido refutada em vários estudos, pesquisas recentes corroboram suas predições, apresentando avanços teóricos e novas ferramentas analíticas. Ademais, até mesmo os críticos consideram a TNB uma teoria elegante, facilmente testável e útil para o desenvolvimento teórico na ecologia.
Maximum annual precipitation reconstruction at successive 500-year intervals in South America
Freshwater Biology, Dec 19, 2020
1. Climate change and species invasions pose serious threats to biodiversity. Daphnia lumholtzi S... more 1. Climate change and species invasions pose serious threats to biodiversity. Daphnia lumholtzi Sars, 1885, a cladoceran species native to Africa, Asia, and Oceania, has How to cite this article: Mantovano T, Bailly D, Ferreira JHD, et al. A global analysis of the susceptibility of river basins to invasion of a freshwater zooplankton (Daphnia lumholtzi).
Neotropical Ichthyology, 2016
Relationship between diet and morphology of cichlid were analyzed considering that the trophic ap... more Relationship between diet and morphology of cichlid were analyzed considering that the trophic apparatus determines differential food use among species. Cichlasoma dimerus and Satanoperca pappaterra showed a generalist diet, while Chaetobranchopsis australis and Crenicichla vittata consumed zooplankton and fish, respectively. Significant correlation between morphology and diet was not found, but C. australis differed from the others species in the upper mouth and longer gill rakers. The morphology data and food size segregated the cichlids into three groups. The first was comprised by C. australis, which has many and longer gill rakers and a more protractile mouth, the second by C. vittata, which have a larger and more-protruded mouth and the third by S. pappaterra and C. dimerus, with a smaller and lower mouth. The latter two groups have more widely spaced gill rakers and consumed larger food. Overall, our results showed different patterns of species grouping when considering morphological or diet data. However, to C. australis the gill rakers determine both the type and size of food. A relação entre dieta e morfologia de ciclídeos foi analisada considerando que o aparato trófico determina o uso diferencial dos recursos alimentares entre as espécies. Cichlasoma dimerus e Satanoperca pappaterra, apresentaram dieta generalista, enquanto Chaetobranchopsis australis e Crenicichla vittata, consumiram zooplâncton e peixes, respectivamente. Nenhuma correlação significativa foi encontrada entre a morfologia e a dieta, entretanto, C. australis se distanciou das demais espécies, por apresentar boca superior e rastros branquiais longos e numerosos. Os dados de morfologia e tamanho do alimento consumido segregaram os ciclídeos em três grupos. O primeiro foi composto por C. australis, que possui rastros branquiais longos e numerosos, além de maior protractibilidade da boca, o segundo por C. vittata, que tem maior amplitude e protrusão da boca e o terceiro por S. pappaterra e C. dimerus que possuem boca pequena e inferior. Os dois últimos grupos apresentaram ainda, maior distância entre os rastros e consumiram alimentos maiores. Nossos resultados mostraram que, quando somente os dados morfológicos são considerados, as espécies foram agrupadas de forma diferente do que quando apenas os dados de dieta foram considerados. Entretanto, para C. australis os rastros branquiais determinam o tipo e tamanho do alimento.
Assessing the role of deep-time Andean and Amazonian landscape evolution on the development of biodiversity
AGU Fall Meeting Abstracts, Dec 1, 2019
Drivers of phylogenetic structure in Amazon freshwater fish assemblages
Journal of Biogeography, 2021
Phylogenetic relatedness among species can provide useful information on the diversification hist... more Phylogenetic relatedness among species can provide useful information on the diversification history and past dispersal events that may have shaped contemporary assemblages. Here, using of the most comprehensive fish occurrence database currently available and a global molecular phylogeny of ray‐finned fishes, we evaluate the respective roles of historical and contemporary processes in generating and maintaining fish assemblage phylodiversity patterns among 97 sub‐drainages covering the Amazon River basin.
Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna
Proceedings of the National Academy of Sciences
Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet... more Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes—the most species-rich continental vertebrate fauna on Earth—to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades. Five abrupt shifts in net diversification rates occurred during the Paleogene and Miocene (between 30 and 7 Ma) in association with major landscape evolution events. Net diversification accelerated from the Miocene to the Recent (c. 20 to 0 Ma), with Western Amazonia having the highest rates of in situ diversification, which led to it being an important source of species dispersing to other re...
Neotropical Ichthyology, 2016
Relationship between diet and morphology of cichlid were analyzed considering that the trophic ap... more Relationship between diet and morphology of cichlid were analyzed considering that the trophic apparatus determines differential food use among species. Cichlasoma dimerus and Satanoperca pappaterra showed a generalist diet, while Chaetobranchopsis australis and Crenicichla vittata consumed zooplankton and fish, respectively. Significant correlation between morphology and diet was not found, but C. australis differed from the others species in the upper mouth and longer gill rakers. The morphology data and food size segregated the cichlids into three groups. The first was comprised by C. australis, which has many and longer gill rakers and a more protractile mouth, the second by C. vittata, which have a larger and more-protruded mouth and the third by S. pappaterra and C. dimerus, with a smaller and lower mouth. The latter two groups have more widely spaced gill rakers and consumed larger food. Overall, our results showed different patterns of species grouping when considering morph...
Biodiversity - The Dynamic Balance of the Planet, 2014
Iheringia. Série Zoologia, 2013
Neste estudo, usamos dois tipos de modelagem de distribuição de espécies (correlativo e mecanísti... more Neste estudo, usamos dois tipos de modelagem de distribuição de espécies (correlativo e mecanístico), com o objetivo de avaliar o efeito das mudanças climáticas sob a distribuição geográfica de Rhinella granulosa (Spix, 1824), espécie inserida principalmente no bioma Caatinga. Avaliamos a predição, levantada por outros autores, de que espécies de anfíbios distribuídos em climas quentes terão suas distribuições espaciais restringidas por aumento da temperatura considerando cenários futuros. Na abordagem correlativa, os resultados mostraram que as distribuições espaciais geradas pelo modelo de distância Euclidiana foram mais conservativas, ou seja, as áreas que apresentaram menor distância do nicho ótimo se restringiram às áreas de distribuição real da espécie (Caatinga) e às pequenas regiões que abrangem o bioma Cerrado. A abordagem mecanística apresentou resultados menos conservativos, onde o habitat indicado como adequado para R. granulosa está contido em grande parte da América do...
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Papers by Fernanda Cassemiro