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Grabaciones en vídeo de los seminarios de la EBD
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Mostrando el intervalo 61 - 80 de 80 resultados.
Nombre Tamaño Descargas
27_04_2017, Bruno Suarez
Título: Assembly patterns of mammal communities in a fragmented agroecosystem Resumen: The recognition of the structure of ecological communities is the main objective of community ecology. Observed patterns are fundamental to know the relative importance of the different factors that determine the structure of these ecological communities. This is because once the pattern is recognized, the question is to investigate which are the underlying processes causing that pattern. Currently, species local coexistence is better understood considering not only environmental factors or interactions among species, but also the regional distribution of the species under study. The general aim of the Thesis is to describe the assembly patterns of mammal communities in a fragmented agroecosystem and infer possible underlying processes that may cause these patterns. To do this, we follow a regional-to-local perspective.
267,4MB 73
27_04_2017, Fran Oficialdegui
Invasión del cangrejo rojo americano, Procambarus clarkii: origen, mecanismos responsables de su éxito invasor y consecuencias de la invasión. Resumen: Las invasiones biológicas son consideradas, hoy en día, una de las principales y más severas causas de pérdida de biodiversidad, y específicamente, en ecosistemas dulceacuícolas. Desde un punto de vista multidisciplinar, esta tesis se centra en el estudio de una de las especies invasoras más conocidas y extendidas a lo largo de todo el mundo: el cangrejo rojo americano (Procambarus clarkii). En grandes líneas, los objetivos son (1) conocer la historia de la invasión en Europa desde un punto de vista filogeográfico, la estructura y conectividad entre las distintas poblaciones; (2) estudiar la expresión de proteínas para saber cómo los individuos hacen frente a nuevas condiciones abióticas; (3) evaluar la compleja interacción entre dos especies invasora de cangrejo (Procambarus clarkii y Pacifastacus leniusculus); y finalmente, evaluar las consecuencias de la invasión sobre (4) especies de macroinvertebrados, (5) anfibios a causa de la quitridiomicosis y (6) otras especies de cangrejos nativos europeos a consecuencia de la afanomicosis o peste del cangrejo.
310,1MB 72
27_07_2017, Gregorio Moreno Rueda
The cost of begging: Does it exist? And if so, is it necessary to guarantee honest parent-offspring communication? Several theoretical models on the evolution of begging predicts that begging must be costly to be an honest, and evolutionarily stable, signal of need. However, the empirical search for begging cost has been unsuccessful, with proposed costs of begging, such as energy, attraction of predators, or reduced growth, not being universal or sufficient to explain the evolution of begging. Nonetheless, recent research points to a cost of begging in the form of reduced immunocompetence. Laboratory experiments with an array of bird species repetitively support the contention of a negative correlation between begging effort and immunocompetence. Moreover, my co-workers and I have shown that the negative impact of begging on immune system is not compensated by the increased ingest of food in fiercely begging nestlings. Furthermore, in a long-term field experiment, we have modified begging behaviour of pied flycatcher (Ficedula hypoleuca) nestlings, finding that begging level is under natural selection, and that its trade-off with immune system is key for understanding the impact of begging on fitness. In overall, although the subjacent cause of the relationship between begging and immune system remains unclear, recent findings suggest that offspring begging exaggeratedly may incur in an immunological cost, which has shaped the evolution of begging. However, these empirical results, demonstrating that begging is associated with a “cost”, do not demonstrate that such a cost is necessary for begging to be honest and evolutionarily stable. Begging, as other behaviours, might be inevitably associated to physiological processes, conducing to unavoidable trade-offs. In fact, several mathematical models predict that cheap begging may be honest and evolutionarily stable. The model in which I am working, as other models, predicts that begging does not require be costly to be honest, but the cost increases information contained in the signal.
315,5MB 85
27_10_2015 Thomas Lenormand, Measures of fitness opening the Pandora’s box
Although there is no difficulty in theory in estimating fitnesses, in practice, the difficulties are virtually insuperable” (Lewontin, 1974).Fitness is a key concept in evolutionary biology. In many models, this is a quantity that can be defined without (too much) ambiguity. When it comes to test these models of evolution and measure fitness empirically, however, many difficulties arise, in addition to these definitional problems. In this presentation, I will try to summarize and provide an overview of these issues. I will present different approaches to measure fitness in the lab or in the field, distinguishing 'forward' and 'backward' methods. To illustrate each case, I will use examples from my work that include some of the most precise estimates that have been obtained to date. I will finally relate the problems of fitness measures to important debates in evolutionary biology.
288,6MB 28
27_10_2016, Maria Lumbierres
Título: Modelling the biomass of Doñana's marsh vegetation using land surface phenology Resumen: Doñana marsh is one of the most important wetlands in Europe; however, it is under extreme human pressure. Remote sensing techniques have proved to be an effective method for modeling and monitoring biomass. The main objective of this project was to model the Doñana marsh biomass, to study the vegetation dynamics of the last 15 years and at the same time to predict the biomass in the future. This project consisted in four different steps: first, to mode the phenological curve, second, to calibrate the metrics of the phenological curve with the biomass production, third, to validate the model, and fourth, to map the biomass and analyze the main patterns of distribution and production. The results showed that it was possible to model the biomass production on the marsh using the NDVI; however it was clear that the high variability of the marsh made the process of modelling challenging. This variability is the result of a highly dynamic ecosystem that interplays water, soil, vegetation, and the presence of cattle. We hope this research can be a starting point to a more deeply research into the Doñana marsh biomass and be a tool for scientifically based management of the cattle in the marsh.?
495,9MB 238
28_005_2015, Jonathan Evans, Why and how do sperm find their way to particular conspecific egs
, Why (and how) do sperm find their way to particular conspecific eggs?Sexual selection (essentially the competition for mates) is traditionally studied in highly mobile organisms with complex behavioural repertoires, sophisticated visual systems, and obvious adaptations that function in the context of increasing reproductive fitness. It is far less obvious how sexual selection operates in organisms that are immobile (e.g. clamped to the seabed) and release gametes seemingly haphazardly into the external environment (i.e. sessile or sedentary external fertilizers). Indeed, Charles Darwin comically dismissed the possibility of sexual selection in such taxa in his original treatise of the topic, arguing that these organisms have ‘too low mental powers’ to be capable of the subtleties of mate choice and mating competition. The aim of this talk will be to convince you otherwise. I will summarise a series of playful experiments on mussels and sea urchins that led to the observation that these taxa exhibit sophisticated processes of sperm-egg interaction that ultimately facilitate sexual selection at the level of the gamete. Our work on these systems has revealed preliminary insights into the complex patterns of selection on ejaculates and tantalizing evidence that eggs release subtle variations in chemical signals that may facilitate the fusion of genetically compatible gametes. I’ll end the talk with some inevitable speculation on the mechanisms that might drive these processes, with the firm hope that someone far more qualified than me will put me on the right track.
304,3MB 55
28_04_2016 Alazne Diez, Olfactory clues related to mosquito attraction
Vector-borne pathogens play an important role in the regulation of wild populations and are model systems for ecological and evolutionary studies. The evolution of these systems is the result of triangular affairs between the parasite, the vector (mosquito) and the vertebrate host. Vectors present important interspecific and interpopulation differences in their feeding behaviour and consequently, interact with their pathogens with different frequencies. As model systems, we will use two multi-host/multi-vector pathogens (Plasmodium and West Nile virus), both transmitted by mosquitoes, and Turdus merula and Passer domesticus like a host. In particular, we will analyse how different host individual characteristics may affect vector attraction and how the heterogeneity on host attractiveness may affect the transmission dynamics of pathogens. We will focus special attention of odorant bird, the feeding behaviour of mosquitoes (mammals vs birds) and the influence of the parasite in the vector and host behaviour. This information may increase our understanding on the dynamics of transmission of numerous vector borne diseases, including pathogens potentially dangerous for humans and wildlife.
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28_05_2016 Jiayue Yan
Epidemiological models for the transmission of infectious diseases used to assume that different hosts are equally appealing to their vectors, that vectors and hosts interact randomly and tended to ignore the impact of host-trait heterogeneity on disease transmission. However, recent studies have shown that mosquitoes feed disproportionately on some host species in relation to what may be expected from their relative abundance. This phenomenon may dramatically alter the host-pathogen contact rate and thus the transmission dynamics of infectious diseases. My thesis will focus on identifying the impact of host morphology, infection status and condition of the attractiveness for blood-seeking mosquitoes. First, we will review what sort of traits may serve as searching cues for host-seeking mosquitoes. Second, we will investigate the relationship between different bird traits (e.g. morphology, metabolism, infection status,) and mosquito attraction at intra- and interspecific levels. Finally, how the competence of different bird species as host of West Nile virus is related to taxonomy and immune system characteristics. By far, we have achieved some preliminary results but your suggestions will be highly welcome for our upcoming works.
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28_09_2017, Camila Mazzoni
Can RAD-Seq help sea turtle conservation? Leibniz Institute for Zoo and Wildlife Research , Berlin. Department of Evolutionary Genetics From vulnerable to critically endangered, the seven existing sea turtle species have long suffered from anthropogenic actions, such as overhunting/poaching, large-scale fishing activities, pollution and habitat degradation. Different phenomena such as hybridization and extreme low molecular diversity have been detected for some populations in different studies, but it is unclear how the recent pressures have been involved in changes in the evolutionary history of sea turtles. The amount and diversity of molecular markers available to study such influences is still very low and analyses lack statistical confidence in many cases due to low variation and/or high levels of shared SNPs. We have decided to use one single genomic approach that can boost the number and variety of nuclear molecular markers available for all sea turtle species. Assuming a deceleration of evolutionary rates in sea turtles, we have used the same Double-Digest Restriction Associated DNA (ddRAD) sequencing methodology for the five sea turtle species with worldwide distribution and generated thousands of new molecular markers that will be useful for a large number of important conservational questions, such as levels of population structuring and composition of mixed-stock. The approach we present in this study is a simple but effective solution to largely deepen the knowledge upon ddRAD data produced that can be transferred to virtually any given species or population
662,9MB 9
29_09_2015, Eduardo de la Peña, Interacciones planta_suelo en sistemas naturales, mecanismos de funcionamiento e implicaciones para conservación y manejo de ecosistemas
Eduardo de la Peña (IHSM-CSIC/ Univ. Gent), A pesar de la inmensa diversidad de especies que habitan en el suelo y de su importancia funcional tanto a nivel de comunidad como de ecosistema, la teoría ecológica ha tenido principalmente en cuenta las interacciones que ocurren en la parte aérea de las plantas dando menor importancia a lo que ocurre en el suelo. Sin embargo, durante la última década se ha revelado la importancia que tienen las interacciones planta-suelo sobre diferentes procesos que se dan en la parte aérea. Estos estudios han demostrado que estas interacciones son imprescindibles no sólo para entender la dinámica de la comunidad vegetal sino también las respuestas de otros niveles tróficos como son los herbívoros foliares, sus enemigos naturales, polinizadores, etc. Durante mi presentación analizaré este tipo de relaciones en algunos sistemas naturales (dunas costeras, brezales atlánticos, bosques templados caducifolios) que ilustran la importancia de estas interacciones para el funcionamiento y dinámica de la comunidad vegetal y sus implicaciones en el manejo y la restauración de ecosistemas
306,7MB 65
29_10_2015, Isabelle Chuine, Let the niche be functional
Let the niche be functional, Isabelle Chuine (Centre d’Ecologie Fonctionnelle et Evolotive, Montpellier). Hutchinson definition of the niche has had a tremendous impact on niche modelling and inspired the most prolific species distribution models (SDMs) ever. Those models, called correlative SDM, relate statistically the species presence/absence to various environmental descriptors. They are very much specific and precise, but lack some generality and realisms in the sense of Levins. In this talk I propose another definition of the niche based on species traits and present a new generation of SDMs, namely process-based SMDs, that I use to predict the geographical distribution of forest tree species in Europe. Process-based models are sometimes less precise than correlative models, but are more realistic and more general. I will present some recent results on projections of species future distribution changes as well as projections of past changes (Holocene). Finally I will present how such models can be used to study the impact of phenotypic plasticity on range size and distribution changes, as well as current and future selection gradient of key adaptive traits.
356,6MB 48
30_04_2015 Miguel Clavero, De cómo es que el cangrejo autóctono no es autóctono
Puede ocurrir que se pierda la noción del carácter exótico de especies que se introdujeron hace mucho tiempo. Pareciera que cangrejos de río los hubiera habido en España de siempre, porque aquí estaban al menos desde antes de que naciera la persona más vieja que haya conocido la persona de más edad que viva hoy. Pero la revisión de la información generada desde diversas disciplinas muestra que una introducción desde Italia es la única explicación parsimoniosa para la presencia de Astropotamobius italicus (el “cangrejo autóctono”, tiene su gracia) en la península ibérica.
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30_11_2017, Jorge Doña
The diversification history of highly host-specific symbionts: the case of bird feather mites Since Heinrich Fahrenholz proposed his rule back in 1913, the idea of symbionts speciating following host speciation (i.e., cospeciating) has dominated research on parasite evolutionary ecology. Recent studies, however, have shown that host-shift speciation (speciation after switching to a new host species) is almost as relevant as cospeciation in explaining symbiont diversification. The relative importance of these processes is highly variable among host-symbiont systems and ranges from strict cospeciation to extensive host-switching, according to system features such as the mode of transmission of symbionts: permanent and vertically transmitted symbionts, such as bird feather mites, belong to the extreme end of the continuum in which cospeciation alone should explain symbiont diversification. In this thesis, we have first developed tools for the study of feather mites, and we have investigated key aspects of their ecology relevant to understand their evolution. Then, with the help of this knowledge and tools, we studied the diversification history of feather mites in a macroecological context. In this talk, I will give an overview of these results and of ongoing works. Overall, I will show the unexpected relevance of host-shift speciation on the diversification history of feather mites. And, lastly, in the light of ecological fitting theory, I will discuss why host-shift speciation should no longer be considered irrelevant even for permanent and highly host-specific symbionts.
317,1MB 4
31_05_2017, Eline Lorenzen
Título: Biogeographic insights from past and present megafauna DNA Resumen: Next-generation DNA sequencing has revolutionized the way we can study evolutionary and ecological processes using genomic data. In this talk, I will show how genomic data can be used in an evolutionary and ecological context, to understand the past and present diversity, distribution, and dynamics of megafauna (large mammal) species and communities. I will discuss how DNA retrieved from ancient material including the bones, teeth and gut content of Late Pleistocene megafauna can be used to infer the past ecology and population dynamics of extinct species, and demonstrate how DNA extracted from sediments can be used to reconstruct the palaeoenvironments once inhabited by these Ice Age giants. Furthermore, using genome-wide data from the polar bear, I will demonstrate how population genomics has been used to estimate the age of the species, reconstruct the joint demographic history of polar bear and brown bear, and identify candidate genes under positive selection in the polar bear lineage that have enabled the species to survive the extreme conditions of life in the High Arctic.
527,9MB 64
7_06_2017, Ian Newton
Título: Bird migration Resumen: Dr. Ian Newton earned a Ph.D. at Oxford University under the tutelage of David Lack. He has been interested in birds since his childhood. As a teenager he became particularly fascinated by finches, and undertook doctoral and post-doctoral studies on them. His interest in that group has continued to the present time. Beginning in the 1970s, Dr. Newton conducted extensive research on the long-term impacts of organochlorine pesticides on several raptor species, and on the population ecology of the Eurasian Sharrowhawk. His 30-year study of a Eurasian Sparrowhawk population nesting in southern Scotland has resulted in what many consider to be the most detailed and longest-running study of any population of birds of prey. In 1979, he produced the classic book, “Population Ecology of Raptors,” and a comprehensive monograph on the Eurasian Sparrowhawk followed in 1986. Dr. Newton’s research in avian population ecology focuses on the factors that limit bird numbers and distributions, including pesticide impacts. From 1989-2000, Ian headed the Avian Biology Section at the Monks Wood Research Station, and has continued his research on raptors since his “retirement” in 2000. He has authored, or co-authored, 13 books, published over 300 technical papers, and made frequent television and radio appearances. He has served as President of the British Ornithologists’ Union and the British Ecological Society, as Chairman of the Royal Society for the Protection of Birds in the United Kingdom, and of The Peregrine Fund in the United States. He is the current Chairman of the British Trust for Ornithology. Dr. Newton has received numerous awards, including Order of the British Empire, the Union Medal and Goodman-Salvin Medal of the British Ornithologists’ Union, and the Elliot Coues Award of the American Ornithologists’ Union.
704,3MB 70
8_06_2017, Jonathan Wright
Título: Life history evolution in a changing world: /r/- versus /K/-selection and the adaptive alignment of pace-of-life syndromes Resumen: This presentation describes a novel perspective on life history evolution that combines recent advances in /r/- versus /K/-selection theory with behavioural ecology theory on pace-of-life syndromes (POLS). These theories predict phenotypic co-variation in life history, physiological, morphological and behavioural traits as a continuum from the fast reproducing short-lived bold, aggressive and highly dispersive /r/-selected types at one end of the POLS to the slow reproducing long-lived cautious, shy, plastic and socially-responsive /K/-selected types at the other. We propose that such variation in life histories and the associated individual differences in behaviour can be explained through their eco-evolutionary dynamics with population density – a single and ubiquitous selective component that is present in all biological systems. Contrasting regimes of environmental stochasticity are expected to affect population density in time and space and create differing patterns of fluctuating /r/- versus /K/-selection, and this generates variation in fast versus slow life-histories within and between populations. We therefore predict that a major axis of phenotypic and genetic co-variation in life history, physiological, morphological and behavioural traits (i.e. the POLS) should align with the major trade-off in the multivariate fitness landscape created by these fluctuations in /r/- versus /K/-selection. Phenotypic plasticity and/or genetic (co-)variation generated along this major axis in life history trait co-variation is thus expected to facilitate rapid and adaptively coordinated changes in various aspects of life history within and between populations and/or species. In addition, negative frequency-dependent selection on the different individual types, such as on fast aggressive /r/-types of individuals when at high densities, could further exaggerate phenotypic variation along the POLS caused by fluctuations in population density. The /r/- vs /K/-selection POLS framework presented here therefore provides a series of clear and testable predictions, the results of which will further our fundamental understanding of life history evolution and thus our ability to predict natural population dynamics in the face of environmental change.
578,9MB 17
8_11_2001, Xim Cerda
la temperatura como factor clave de la organizacion de las comunidades de hormigas en Doñana
189MB 29
9_03_2017, Ruben Bernardo
Título: Population dynamics of voles: Characterization and modelling of global spatio-temporal patterns Resumen: The understanding of the population fluctuations of rodents, especially voles, is fundamental because their ecological, healthy and economic importance. The literature shows a high variety in schools of thought about what the drivers of the population fluctuations are. However no study provides information about the general causes of the population fluctuations. Therefore the global goal of the Thesis is to identify the general trends and drivers of the population fluctuations of voles. Nevertheless, the specific goals of the Thesis are: (1) to provide a public and standardized database with the capture-recapture data of most of the vole populations sampled since 60s; (2) to describe the survival and reproductive rates of the different populations and species; (3) to identify the general drivers of the population changes; and (4) to detect early warning signals of vole outbreaks.
183,7MB 71
9_03_2017, Setefilla Buenavista
Título: Desafíos para la persistencia de grandes felinos Neotropicales en paisajes dinámicos dominados por la actividad humana Resumen: Las actividades humanas generan grandes y acelerados cambios globales, cuyos impactos en la naturaleza aumentan conforme crece la presión antrópica. Como consecuencia, la biodiversidad se encuentra amenazada a lo largo y ancho del planeta, siendo un gran número de especies las que han desaparecido o en las que han disminuido sus poblaciones. Sin embargo, recientemente se están proporcionando evidencias a favor de la recuperación del nivel de abundancia y distribución histórica de algunos grandes mamíferos terrestres debido a la recolonización de ciertos ambientes humanizados. La finalidad de este proyecto de tesis es conocer qué efecto tendrán sobre especies con altos requerimientos espaciales, los cambios en el uso del paisaje por motivos socioeconómicos que ocurren en la actualidad y la presencia de nuevas presas provenientes de reintroducciones. Para ello, se analizará si los grandes felinos Neotropicales como el jaguar y el puma, pueden hacer uso de hábitats y de presas producto de la humanización del medio natural. Nuestra hipótesis inicial de trabajo es que la combinación de ciertos cambios en las actividades humanas podría tener un efecto positivo en la recuperación de las poblaciones de estos grandes felinos neotropicales en paisajes humanizados, al reducir los conflictos socioeconómicos que enfrentan a los depredadores con la población rural, y a su vez permitir la persistencia de sus poblaciones en hábitats más favorables para estas especies. Por lo tanto, la viabilidad poblacional de estas especies amenazadas podría modificarse en las áreas más transformadas de su distribución, mejorando su estado de conservación.
290,5MB 70
9_07_2017, Santiago Montero
Ponente: Santiago Montero-Mendieta Title: A genomic view on the diversification of neotropical frogs Abstract: The genus Oreobates is a clade of Neotropical frogs of which very little is known. More than half of the 24-named species have been described in the last ten years. They are distributed across a wide range of habitats and altitudes in South America. Unfortunately, some Oreobates species have been only found once. This is particularly a problem for traditional phylogeography and phylogenetics studies based on data from a few orthologous loci from multiple individuals. With the increasing usage of high throughput sequencing we are now able to sequence big amounts of orthologous loci, allowing the use of less individuals. In organisms with big genome sizes, such as amphibians, a common way to obtain a reduced representation of the genome is by transcriptome sequencing. Using a transcriptome-based exon capture approach, in my PhD thesis I will use thousands of orthologous genes to study evolution rates, demographic history and adaptation patterns on the frogs of the genus Oreobates. The results of this project will allow us to solve questions such as: “Is the evolution rate lower in the highland Oreobates species?”, “Is the genetic diversity larger in montane Oreobates species?” or “Are there any genes related to adaptation to dry forest in Oreobates?”.
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Mostrando el intervalo 61 - 80 de 80 resultados.