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Bird Appearances and Similarities
Figura, Roman ; Komárek, Stanislav (advisor) ; Daněk, Tomáš (referee) ; Jaroš, Filip (referee)
The presented work deals with a striking, yet usually neglected phenomenon by researchers, the similarity between the forms of different (closely unrelated) bird taxa. It mainly concerns visual signs of the body surface, the work also deals with other signs, including behavioral ones. The thesis demonstrates that these are not a few curious similarities, but a truly robust phenomenon, which apparently cannot be fully explained from a unifying point of view. Only some characters, which the work deals with, help their bearers to crypsis, aposematism or mimesis. In many other cases, their function is unknown. They can carry different functions in the life of their bearers, but it is often not possible to determine a single cause of their occurrence. In terms of the information contained, the work belongs to the largest works dealing with this topic known to the author.
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Fylogeneze a taxonomie vybraných druhů sinic čeledi Merismopediaceae s využitím metody single cell sequencing
POKORNÝ, Jan
Thanks to new molecular methods, which have been used for revision of many traditional cyanobacterial taxa, their real systematic positions have become clearer. Merismopediaceae is a relatively understudied group of Cyanobacteria, therefore many subordinate taxa have not been sufficiently molecularly reviewed. In this thesis standard molecular methods of the polyphasic approach were used on environmental isolates as well as cultured strains of Merismopediaceae taxa. Subsequent phylogeny analysis based on 16S rRNA gene shows the polyplyly of genera Merismopedia and Eucapsis. The thesis also includes the very first molecular evidence of the taxonomic position of the genus Microcrocis.
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Morphological, behavioural and physiological adaptations of island-dwelling birds
Krpcová, Alena ; Albrecht, Tomáš (advisor) ; Mikula, Ondřej (referee)
Morphological, behavioural and physiological adaptations of island-dwelling birds Alena Krpcová prof. Tomáš Albrecht, Ph.D. Abstract Islands represent a model system of evolutionary biology. They are isolated environments in which specific ecological conditions often operate differently than on the mainland. In this context, island taxa develop unique morphological, physiological and behavioural adaptations, collectively referred to as island syndromes, through convergent evolution. This thesis aims to provide an overview of selected island syndromes that have been detected in a large group of vertebrates typically inhabiting islands, the birds (Aves). Attention is paid to body size, wing length and associated flightlessness, as well as changes in life strategies (life span, offspring care, clutch size and egg size), antipredatory behaviour and island tameness, and finally the relationship between the above-mentioned island syndromes and the extinction of island species caused by humans and the invasive organisms that accompany them. Factors operating in island environments that may influence the evolution of selected island syndromes are discussed, and it is suggested that reduced predation pressure on islands and an energetic trade-offs between investments in survival, defence and reproduction could be...
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