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Mitchell, Edward

Nom
Mitchell, Edward
Affiliation principale
Site web
Fonction
Professeur ordinaire
Email
edward.mitchell@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/357
_
0000-0003-0358-506X

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  • Publication
    Accès libre
    Checklist, diversity and distribution of testate amoebae in Chile
    Fernández, Leonardo D
    ;
    Lara, Enrique 
    ;
    Mitchell, Edward 
    Bringing together more than 170 years of data, this study represents the first attempt to construct a species checklist and analyze the diversity and distribution of testate amoebae in Chile, a country that encompasses the southwestern region of South America, countless islands and part of the Antarctic. In Chile, known diversity includes 416 testate amoeba taxa (64 genera, 352 infrageneric taxa), 24 of which are here reported for the first time. Species−accumulation plots show that in Chile, the number of testate amoeba species reported has been continually increasing since the mid-19th century without leveling off. Testate amoebae have been recorded in 37 different habitats, though they are more diverse in peatlands and rainforest soils. Only 11% of species are widespread in continental Chile, while the remaining 89% of the species exhibit medium or short latitudinal distribution ranges. Also, species composition of insular Chile and the Chilean Antarctic territory is a depauperated subset of that found in continental Chile. Nearly, the 10% of the species reported here are endemic to Chile and many of them are distributed only within the so-called Chilean biodiversity hotspot (ca. 25°S-47°S). These findings are here thoroughly discussed in a biogeographical and evolutionary context.
  • Publication
    Accès libre
    Dispersal limitations and historical factors determine the biogeography of specialized terrestrial protists
    Singer, David 
    ;
    Mitchell, Edward 
    ;
    Payne, Richard J
    ;
    Blandenier, Quentin 
    ;
    Duckert, Clément
    ;
    Fernández, Leonardo D
    ;
    Fournier, Bertrand 
    ;
    Hernández, Cristián E
    ;
    Granath, Gustaf
    ;
    Rydin, Håkan
    ;
    Bragazza, Luca
    ;
    Koronatova, Natalia G
    ;
    Goia, Irina
    ;
    Harris, Lorna I
    ;
    Kajukało, Katarzyna
    ;
    Kosakyan, Anush 
    ;
    Lamentowicz, Mariusz
    ;
    Kosykh, Natalia P
    ;
    Vellak, Kai
    ;
    Lara, Enrique 
    Recent studies show that soil eukaryotic diversity is immense and dominated by micro‐organisms. However, it is unclear to what extent the processes that shape the distribution of diversity in plants and animals also apply to micro‐organisms. Major diversification events in multicellular organisms have often been attributed to long‐term climatic and geological processes, but the impact of such processes on protist diversity has received much less attention as their distribution has often been believed to be largely cosmopolitan. Here, we quantified phylogeographical patterns in Hyalosphenia papilio, a large testate amoeba restricted to Holarctic Sphagnum‐dominated peatlands, to test if the current distribution of its genetic diversity can be explained by historical factors or by the current distribution of suitable habitats. Phylogenetic diversity was higher in Western North America, corresponding to the inferred geographical origin of the H. papilio complex, and was lower in Eurasia despite extensive suitable habitats. These results suggest that patterns of phylogenetic diversity and distribution can be explained by the history of Holarctic Sphagnum peatland range expansions and contractions in response to Quaternary glaciations that promoted cladogenetic range evolution, rather than the contemporary distribution of suitable habitats. Species distributions were positively correlated with climatic niche breadth, suggesting that climatic tolerance is key to dispersal ability in H. papilio. This implies that, at least for large and specialized terrestrial micro‐organisms, propagule dispersal is slow enough that historical processes may contribute to their diversification and phylogeographical patterns and may partly explain their very high overall diversity.
  • Publication
    Accès libre
    Soil protistology rebooted: 30 fundamental questions to start with
    Geisen, Stefan
    ;
    Mitchell, Edward 
    ;
    Wilkinson, David M
    ;
    Adl, Sina
    ;
    Bonkowski, Michael
    ;
    Brown, Matthew W
    ;
    Fiore-Donno, Anna Maria
    ;
    Heger, Thierry 
    ;
    Jassey, Vincent E.J
    ;
    Krashevska, Valentyna
    ;
    Lahr, Daniel J.G
    ;
    Marcisz, Katarzyna
    ;
    Mulot, Matthieu 
    ;
    Payne, Richard
    ;
    Singer, David 
    ;
    Anderson, Roger O
    ;
    Charman, Dan J
    ;
    Ekelund, Flemming
    ;
    Griffiths, Bryan S
    ;
    Rønn, Regin
    ;
    Smirnov, Alexey
    ;
    Bass, David
    ;
    Belbahri, Lassaâd 
    ;
    Berney, Cédric
    ;
    Blandenier, Quentin 
    ;
    Blandenier, Quentin
    ;
    Chatzinotas, Antonis
    ;
    Clarholm, Marianne
    ;
    Dunthorn, Micah
    ;
    Feest, Alan
    ;
    Fernández, Leonardo D
    ;
    Foissner, Wilhelm
    ;
    Fournier, Bertrand 
    ;
    Gentekaki, Eleni
    ;
    Hájek, Michal
    ;
    Helder, Johannes
    ;
    Jousset, Alexandre
    ;
    Koller, Robert
    ;
    Kumar, Santosh
    ;
    La Terza, Antonietta
    ;
    Lamentowicz, Mariusz
    ;
    Mazei, Yuri
    ;
    Santos, Susana S
    ;
    Seppey, Christophe V.W
    ;
    Spiegel, Frederick W
    ;
    Walochnik, Julia
    ;
    Winding, Anne
    ;
    Lara, Enrique 
    Protists are the most diverse eukaryotes. These microbes are keystone organisms of soil ecosystems and regulate essential processes of soil fertility such as nutrient cycling and plant growth. Despite this, protists have received little scientific attention, especially compared to bacteria, fungi and nematodes in soil studies. Recent methodological advances, particularly in molecular biology techniques, have made the study of soil protists more accessible, and have created a resurgence of interest in soil protistology. This ongoing revolution now enables comprehensive investigations of the structure and functioning of soil protist communities, paving the way to a new era in soil biology. Instead of providing an exhaustive review, we provide a synthesis of research gaps that should be prioritized in future studies of soil protistology to guide this rapidly developing research area. Based on a synthesis of expert opinion we propose 30 key questions covering a broad range of topics including evolution, phylogenetics, functional ecology, macroecology, paleoecology, and methodologies. These questions highlight a diversity of topics that will establish soil protistology as a hub discipline connecting different fundamental and applied fields such as ecology, biogeography, evolution, plant-microbe interactions, agronomy, and conservation biology. We are convinced that soil protistology has the potential to be one of the most exciting frontiers in biology.