29 ott. 2019 - Roberto Arrigoni

20191029 Seminario Arrigoni

Verso una nuova sistematica dei coralli integrando genomica, morfologia ed analisi filogenetiche

Presenta: Roberto Arrigoni

Joint Research Centre (JRC) – Ispra (VA)

Un'accurata definizione delle specie e delle loro relazioni filogenetiche costituisce una questione fondamentale per la biologia evoluzionistica e per la sistematica, ed inoltre presenta importanti implicazioni per le strategie di conservazione. In ambiente marino, i coralli duri (Cnidaria, Scleractinia) sono i principali biocostruttori delle scogliere coralline, ecosistemi tra i più ricchi di biodiversità al mondo ma contemporaneamente tra i più fragili ed in declino. Le sclerattinie risultano tuttavia estremamente difficili da identificare a causa della loro elevata plasticità fenotipica e variazione morfologica geografica. In questo seminario, verranno presentati alcuni esempi di come, all'interno di un robusto contesto filogenetico, l'integrazione tra tecnologie di Next Generation Sequencing, tassonomia classica, e nuovi caratteri morfologici ed ecologici stia portando ad una più chiara definizione dei confine tra specie e delle loro relazioni nei coralli. In particolare, verranno mostrati i vantaggi della tecnica di rappresentazione ridotta del genoma RADseq rispetto all'applicazione dei classici geni barcoding. Inoltre, i dati mostrati presenteranno interessanti risvolti biogeografici e paleontologici, ed in termini di biodiversità criptica.

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8 ott. 2019 - Roberto Sacchi

20191008 Seminario Sacchi

La funzione delle proteine nei segnali chimici di una lucertola polimorfica

Presenta: Roberto Sacchi

Università di Pavia, Dipartimento di Scienze della Terra e dell'Ambiente, Laboratorio di Acque Interne

Le lucertole sono buoni modelli per studiare la comunicazione chimica negli animali in quanto possiedono ghiandole epidermiche che producono secrezioni cerose usate come segnali in diversi contesti sociali. Questi secreti sono una miscela di lipidi e proteine assai complesse. I lipidi sono coinvolti per trasmettere informazioni sulla qualità e sulle condizioni individuali, mentre non è chiara la funzione delle proteine. I pochi dati disponibili suggeriscono che la loro funzione sia quella di trasmettere informazioni relative all'identità del segnalatore. Le ricerche condotte negli ultimi tre anni sulla Lucertola muraiola (Podarcis muralis) hanno dimostrato che le proteine dei secreti delle ghiandole femorali sono effettivamente utilizzate come segnali di identità o di strategia, ma il quadro che ne emerge è probabilmente molto più complesso.

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10 sett. 2019 - Jacob Brodersen

20190910 Seminario Brodersen

On the causes and consequences of intraspecific phenotypic variation in aquatic ecosystems

Presenta: Jacob Brodersen

Department of Fish Ecology & Evolution, Eawag Swiss Federal Institute of Aquatic Science and Technology
Institute of Ecology & Evolution; University of Bern

An overarching goal of modern biology is to understand how individual phenotypic variation originates, how it is maintained and how it influences the surrounding ecosystem. Associated studies need a trans-disciplinary approach, integrating evolutionary biology with spatial-, trophic- and behavioral ecology. Although the theme is applicable across ecosystems and organisms, it is particularly well studied in freshwater fish, which further makes the research relevant for a multitude of applied topics in aquatic ecology.
Dr Brodersen is paying particular close attention to subjects regarding animal movement and migration. Migration can be seen as a behavioral trait, of which intra- and interpopulation variation is important for both evolution and ecosystem dynamics. It is clear that animal movement and migration plays a particular role in adaptive and non-adaptive speciation, as it both affects selection in one or multiple habitats and in itself controls gene flow and spatio-temporal isolation between populations. Interestingly, this intra- and interspecific variation in movement can be caused by both underlying genetic differences and environmental influence and behavioral canalization e.g. through social interactions. It is hence a subject that opens up for a large integration of ecology, ethology and evolution and further understanding of eco-evolutionary interactions.
In this talk Dr Brodersen will present his own research on the topic and he will end with explaining the relevance of this work in ecosystem management and conservation.

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17 giu. 2019 - Roberto Camassa

20190617 Seminario Camassa

Sedimentation and aggregation in stratified water
(with preliminary data from field experiment in Gokyo lakes, Sagarmatha National Park)

Presenta: Roberto Camassa

University of North Carolina

Particle settling through density stratified fluids experience hydrodynamic interactions that can significantly alter their behavior with respect to their homogeneous fluids counterpart. These are ultimately due to the complex interplay between diffusion, advection, and geometry (through physical boundary conditions). This talk will review results from an ongoing investigation of the relative and overall importance of some newly identified mechanisms that govern the settling and aggregation behavior of particles under different conditions. Preliminary water column sampling data from a field experiment in the Gokyo lake II and IV, Sagarmatha National Park, will be presented.

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30 mag. 2019 - Paulo Castro

20190530 Seminario Castro

Freshwater mussels vs climate change: to be or not to be?

Presenta: Paulo Castro

Department of Biology, University of Minho, Portugal

Humans are now appropriating more than 50% of freshwater runoff, many species are overexploited, ecosystems are polluted, over 1 million dams globally widespread fragment rivers and species introductions in freshwater ecosystems. In ecosystems already disturbed, climate change will most likely exacerbate this state. Freshwater mussels (FM: Bivalvia: Unionida) are one of the most imperiled faunal groups on Earth, and their conservation is urgent. Indeed, FM are responsible for numerous important ecosystem services (e.g. water purification), and are a link for the interaction of other aquatic organisms (e.g. pelagic-benthic processes). In addition, due to their high vulnerability, FM can be used as a model organism to assess how may climate change, and its interaction with other stressors, affect freshwater ecosystems. This project is focused on assessing the limits and responses of native mussels to climate change, with a multidisciplinary approach including physiology, phenology, distribution and molecular tools (gene expression and genetic diversity). Composition and salinity of the copepod Leptodiaptomus cf. sicilis from one of the hyposaline lakes will be shown.

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