
Sara VarelaUniversity of Vigo | UVIGO · Faculty of Biology
Sara Varela
PhD
About
99
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Introduction
Paleobiogeographer/paleoecologist
Publications
Publications (99)
Ecological niche modelling is applied broadly in ecology to model a species’ niche and map suitable habitat. The approach links species’ occurrences with environmental predictors to statistically derive response curves. Although commonly applied to study extant taxa, ecological niche modelling is an emerging method in palaeobiology, providing oppor...
The resource‐use hypothesis, proposed by E.S. Vrba, states that habitat fragmentation caused by climatic oscillations would affect particularly biome specialists (species inhabiting only one biome), which might show higher speciation and extinction rates than biome generalists. If true, lineages would accumulate biome‐specialist species. This effec...
The Baynunah Formation has produced a diverse assemblage of plant, invertebrateInvertebrate, and vertebrate fossils that provides the only window onto the terrestrial late Miocene record of the Arabian Peninsula. This chapter reviews and revises the age, biogeography, environments, and ecology of the Baynunah fauna. Biochronological estimates indic...
Climate change is reaching several tipping points, likely resulting in habitat shifts at a global scale. Such changes could have serious consequences for migratory species. For instance, climatic changes may impact the distribution of breeding and non-breeding ranges, resulting in longer migration distances for some species. The flycatchers (Tyrann...
The field of distributional ecology has seen considerable recent attention, particularly surrounding the theory, protocols, and tools for Ecological Niche Modeling (ENM) or Species Distribution Modeling (SDM). Such analyses have grown steadily over the past two decades—including a maturation of relevant theory and key concepts—but methodological co...
Dinosaurs dominated Mesozoic terrestrial ecosystems globally. However, whereas a pole-to-pole geographic distribution characterized ornithischians and theropods, sauropods were restricted to lower latitudes. Here, we evaluate the role of climate in shaping these biogeographic patterns through the Jurassic–Cretaceous (201–66 mya), combining dinosaur...
Citizen science has become a powerful tool for collecting big data on biodiversity. However, concerns have been raised about potential biases in these new datasets. We aimed to test whether citizen science bird databases have more biases than professional scientific databases. Our hypotheses were 1) citizen science databases will have more data on...
Asian cobras (genus Naja ) are venomous snakes distributed from the Middle East to Southeast Asia. Because cobras often live near humans settlements, they are responsible for a large part of snakebite incidents and as such pose a challenge for public health systems. In the light of growing human populations, correctly mapping the present and future...
The Baynunah Formation has produced a diverse assemblage of plant, invertebrate, and vertebrate fossils that provides the only window onto the terrestrial late Miocene record of the Arabian Peninsula. This chapter reviews and revises the age, biogeography, environments, and ecology of the Baynunah fauna. Biochronological estimates indicate an age o...
Our understanding of the emergence and dispersal of the earliest tool-making hominins has been revolutionised in the last decade, with sites in eastern Africa and China pushing records of both events several hundred thousand years earlier than previously thought. In recent years, climate and environmental factors have been considered by many as pri...
Aim
Mammals on islands often undergo remarkable evolutionary changes. The acquisition of ‘low gear’ locomotion, namely short and robust limb elements, has been typically associated with the island syndrome in large mammals and, especially, ruminants. Here we provide an investigative framework to examine biotic and abiotic selective factors hypothes...
The impact of mass extinctions on the body sizes of animals has received considerable attention and debate, as to whether the reduced size of post-extinction organisms is due to the selective extinction of large species, absence of large species as a stochastic effect of low-diversity faunas, or a size decrease within surviving genera and species....
The Baynunah Formation has produced a diverse assemblage of plant, invertebrate, and vertebrate fossils that provides the only window onto the terrestrial late Miocene record of the Arabian Peninsula. This chapter reviews and revises the age, biogeography, environments, and ecology of the Baynunh fauna. Biochronological estimates suggest an age of...
1. Seagrasses such as Zostera marina L. play a key role in coastal ecosystems, enhancing biodiversity, productivity and carbon sequestration. Despite their ecological relevance, their distribution is, to date, insufficiently documented and it is estimated that only a quarter of their global extent is mapped.
2. This study aims to develop a new met...
El conjunto de ideas, métodos y programas informáticos que se conoce como “Modelado de Nicho Ecológico” (MNE)—y el relacionado “Modelado de Distribución de Especies” (MDS)—han sido objeto de intensa exploración e investigación en las últimas décadas. A pesar de existir al menos cuatro síntesis publicadas, este campo ha crecido tanto en complejidad,...
Poorly known species may be cryptically endangered, especially when they inhabit fragmented and threatened habitats. Heart-tongued frogs (genus Phyllodytes, family Hylidae, Lophyohylinae) comprise 17 species of poorly known frogs that have obligatory associations with tank bromeliads. The distributions of all species are restricted to a small, extr...
Eight years of excavation work by the Olduvai Geochronology and Archaeology Project (OGAP) has produced a rich vertebrate fauna from several sites within Bed II, Olduvai Gorge, Tanzania. Study of these as well as recently re-organized collections from Mary Leakey's 1972 HWK EE excavations here provides a synthetic view of the faunal community of Ol...
Starry stonewort (Nitellopsis obtusa) is an alga that has emerged as an aquatic invasive species of concern in the United States. Where established, starry stonewort can interfere with recreational uses of water bodies and potentially have ecological impacts. Incipient invasion of starry stonewort in Minnesota provides an opportunity to predict fut...
Table A. Correlation matrix of environmental variables. Table B. Summary of model evaluations.
(DOCX)
Climate has played a key role in shaping the geographic patterns of biodiversity. The imprint of Quaternary climatic fluctuations is particularly evident on the geographic distribution of Holarctic faunas, which dramatically shifted their ranges following the alternation of glacial-interglacial cycles during the Pleistocene. Here, we evaluate the e...
Full text: rdcu.be/tIj5.
The end of the Pliocene marked the beginning of a period of great climatic variability and sea-level oscillations. Here, based on a new analysis of the fossil record, we identify a previously unrecognized extinction event among marine megafauna (mammals, seabirds, turtles and sharks) during this time, with extinction rates...
En 2016 implementamos un sistema de seminarios de enseñanza en formato de videos libres y accesibles desde internet, con la finalidad de dar a conocer de forma sencilla y en castellano, las bases conceptuales y aplicaciones de la ecología espacial y los modelos de nicho ecológico en estudios de ecología, conservación biológica, epidemiología y agro...
Studying the changes in species ranges during the last glaciation event is an important step towards the understanding of the observed patterns of intra-specific genetic variability. We focused on bumblebees, an interesting biological model to address these questions because cold-adapted species are likely to have experienced different geographical...
Abstract.—In 2016, we implemented a system of seminars for teaching, in open access video format available via the Internet, aiming to show in Spanish and in simple form the conceptual bases and applications of ecological niche modeling in studies of ecology, biological conservation, epidemiology, and agro-biodiversity, as well as its implementatio...
Drought is a global issue that is exacerbated by climate change and increasing anthropogen-ic water demands. The recent occurrence of drought in California provides an important opportunity to examine drought response across ecosystem classes (forests, shrublands, grasslands, and wetlands), which is essential to understand how climate influences ec...
Most scientific papers are not reproducible: it is really hard, if not impossible, to understand how results are derived from data, and being able to regenerate them in the future (even by the same researchers). However, traceability and reproducibility of results are indispensable elements of highquality science, and an increasing requirement of m...
Many studies predict that climate change will cause species movement and turnover, but few have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenarios span...
Species movement under different AOGCM models and RCP in the 2050s.
Y axis presents different AOGCM models. X axis presents different RCP models. The arrow and wind rose are same as Fig. 1.
Distribution change under climate change using Megophrys major as an example.
The figure was generated using R (http://www.R-project.org/), ggplot2 (http://had.co.nz/ggplot2/boo) and raster (http://CRAN.R-project.org/package=raster) softwares, and the maps were created using data downloaded from the GADM database (http://www.gadm.org/) for free use...
Scientific classification and IUCN category of 134 amphibian species analyzed.
Species movement under different AOGCM models and RCP in the 2070s.
Y axis presents different AOGCM models. X axis presents different RCP models. The arrow and wind rose are same as Fig. 1.
In recent years, changes have been detected in the climatic niches of several non-native species. In spite of this, and although Ecological Niche Models (ENMs) assume species show climatic niche conservatism, most studies still use ENM to assess the risks of invasion by alien species. In this study, we tested how niche expansion of the pond slider...
It lived millions of years ago and was three times as large as the great white shark: the megalodon. So far its extinction has been explained with the onset of an ice age. However, researchers at the University of Zurich have now come to the conclusion that responsibility for the decline of the monster shark lays not with the climate, but with othe...
Given its catastrophic consequences, the extinction of apex predators has long been of interest to modern ecology. Despite major declines, no present-day species of marine apex predator has yet become extinct. Because of their vulnerability, understanding the mechanisms leading to their extinction in the past could provide insight into the natural...
1. Climate change and deforestation are suggested to be the main
drivers of decline in pollinators. Forest-dependent species are expected to be the
most affected and Euglossa marianae Nem�esio (Hymenoptera: Apidae), an endemic
species of the highly fragmented Brazilian Atlantic Forest (AF), is believed
to be declining as a consequence of human impa...
Many studies predict that climate change will cause species movement and turnover, but few studies have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenar...
Many studies predict that climate change will cause species movement and turnover, but few studies have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenar...
Currently, researcher use Worldclim variables (worldclim.org) to calibrate ecological niche models (ENM) and then, they project those ENM into past
or future climatic scenarios to map the species potential distribution in the past or in the future. The main problem of this approach is that past and
future climatic scenarios are based on General Cir...
Idealmente deberíamos organizar nuestros “scripts” de R en forma
de paquetes en cada proyecto que desarrollásemos, de manera
rutinaria, al igual que organizamos y guardamos los datos de
campo o del laboratorio en un Excel (como poco) y no los dejamos
anotados a lápiz en hojas sueltas. Hadley Wickham, uno de los
programadores en R más activos del mo...
The impacts of unpredictable ecological perturbations are often assessed via measurements of environmental change only after the event has occurred. Temporal series of satellite images provide a cost-effective way to gather information before ecological perturbations occur. However, in previous studies, the disturbances have neither been always cen...
Studies in biogeography and macroecology have been increasing massively since climate and biodiversity databases became easily accessible. Climate simulations for past, present, and future have enabled macroecologists and biogeographers to combine data on species’ occurrences with detailed information on climatic conditions through time to predict...
data freely availabe at http://ecoclimate.org/
The goal of EcoClimate is to provide an open database of processed climatic simulations in a suitable resolution and user-friendly format for macroecological and biogeographical studies. Our database includes all climate models currently available from CMIP5 and PMIP3 projects for past, present, and...
Orchid bees compose an exclusive Neotropical pollinators group, with bright body coloration. Several of those species build their own nests, while others are reported as nest cleptoparasites. Here, the objective was to evaluate whether the inclusion of a strong biotic interaction, such as the presence of a host species, improved the ability of spec...
Ecological niche models are widely used for mapping the distribution of species during the
last glacial maximum (LGM). Although the selection of the variables and General Circulation
Models (GCMs) used for constructing those maps determine the model predictions, we still
lack a discussion about which variables and which GCM should be included in th...
The fossil record acts as a time machine, providing data on the morphology, ecology and biogeography of ancient species. Therefore, ideally, fossil data should be included in evolutionary, macroecological and biogeographical studies. However, paleontological data are often not used in biological research, in part because of the difficulty of extrac...
Orchid bees compose an exclusive Neotropical pollinators group, with bright body colora- tion. Several of those species build their own nests, while others are reported as nest clep- toparasites. Here, the objective was to evaluate whether the inclusion of a strong biotic interaction, such as the presence of a host species, improved the ability of...
Durante los pasados días 21 de Julio a 8 de Agosto tuvo lugar
el taller Open Science for Synthesis organizado por el National
Center for Ecological Analysis and Synthesis (NCEAS, University
of California Santa Bárbara) y el Renaissance Computing Institute
(RENCI, University of North Carolina), que se celebró simultáneamente
en Santa Barbara (Califo...
Proyecto AVIS1 is an open access citizen science database that stores information collected by
amateur ornithologists about bird occurrences and abundance in Spain. Proyecto AVIS was launched in
2005 and today stores data from 415 species (ca. 90% of bird species in Spain); it covers 30% of the
Spanish territory, including the Canary Islands in the...