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Adaptive radiation of the genus Rattus
Skalíková, Hana ; Frynta, Daniel (advisor) ; Mazoch, Vladimír (referee)
Rats are an important group of rodents originating and living mainly in southeast Asia. They are important pests and reservoirs of zoonosis. Yet, about many species we only have basic information. Here, I summarized available information about 66 species of the genus Rattus and 10 species of the genus Bandicota, Diplothrix, Limnomys, Nesokia and Tarsomys. I focused on distribution, ecology and morphology (body lenght, tail lenght, hind food lenght and ear lenght) and their mutual relationships. The body lenght differs beetwen phylogenetic lineages and beetwen habitats. The other morphological characters (tail lenght, hind food lenght and ear lenght) correlated with body lenght. Further, I describe an adaptive radiation of rats. Rats are separated into several lineages, diferring in their geographic distribution and ecology. Moreover, many species are commensal, that is benefiting from close relationship with humans. Commensalism species can be found in several lineages of rats, therefore commensalism probably developped independently more than once. The commencalism was origined several times. I discuse why are some commensal species more successful than others. Key words: adaptive radiation, Bandicota, commensal species, ecomorphology, Rattus, rodents, southeast Asia
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Adaptive radiation of the genus Rattus
Skalíková, Hana ; Frynta, Daniel (advisor) ; Mazoch, Vladimír (referee)
Rats are an important group of rodents originating and living mainly in southeast Asia. They are important pests and reservoirs of zoonosis. Yet, about many species we only have basic information. Here, I summarized available information about 66 species of the genus Rattus and 10 species of the genus Bandicota, Diplothrix, Limnomys, Nesokia and Tarsomys. I focused on distribution, ecology and morphology (body lenght, tail lenght, hind food lenght and ear lenght) and their mutual relationships. The body lenght differs beetwen phylogenetic lineages and beetwen habitats. The other morphological characters (tail lenght, hind food lenght and ear lenght) correlated with body lenght. Further, I describe an adaptive radiation of rats. Rats are separated into several lineages, diferring in their geographic distribution and ecology. Moreover, many species are commensal, that is benefiting from close relationship with humans. Commensalism species can be found in several lineages of rats, therefore commensalism probably developped independently more than once. The commencalism was origined several times. I discuse why are some commensal species more successful than others. Key words: adaptive radiation, Bandicota, commensal species, ecomorphology, Rattus, rodents, southeast Asia
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The Potential of computed tomography in the research of vertebrates
Piskáčková, Anna ; Frýdlová, Petra (advisor) ; Minařík, Martin (referee)
This thesis explores and classifies the capacities of computed tomography (CT) and mainly microcomputed tomography (micro-CT) in vertebrate research. The thesis pursues the application of the method in imaging the particular structures, tries to gain a knowledge as wide as possible about the studied tissues of vertebrates and about the resolution achieved with micro-CT and evaluates the optimal employment of this method. The aim of this thesis is to propose particular structures ideal for employment of this progressive method with high resolution in morphological, ecomorphological and phylogenetical context of research in vertebrate zoology. At present computed tomography is commonly used diagnostic method, which is employed not only in the medical and veterinary practice but also in biological research. The advantage of computed tomography is it's speed and the fact that it isn't invasive. CT and micro-CT can display mineralized tissues but also soft tissues with used of contrast agents. By micro-CT we create accurate three-dimensional projections of little structures. This can be helpful for example in research of spatially complex skulls and skeletons of even very small vertebrates. At first the thesis tries to map the principles of CT and mikro-CT, the history and the potential of the technique...
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Ecological links between morphology and habitat selection in passerines
Bovšková, Denisa ; Hořák, David (advisor) ; Klvaňa, Petr (referee)
The thesis is focused on relations between avian morphology and habitat selection. This is a summary of comparative studies, dealing this problematics in closely related groups of passerines. Generally, we can classify species to two main groups according to habitat preferences. Aerial species have longer wings probably as a result of adaptation on move in the air and open spaces. In contrast, ground species have generally longer legs as adaptation for running on the ground and pedal locomotion. Longer tarsi are also documented in ground species living in vegetation cover. Species which prefer tall vegetation have short leg probably for better move in branches. Less pronounced morphological differences further reflect habitat preferences at smaller spatial scales within habitat types mentioned above. In addition, some studies reveal that morphological variation reported frequently as reflecting adaptations to feeding preferences shows some links to environmental variation (substrate structure) independent of diet composition, such as bill morphology. Powered by TCPDF (www.tcpdf.org)
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