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Molecular cztogenetic analysis of adaptive radiation in the gecko genus Paroedura (Squamata:Gekkota)
Koubová, Martina ; Kratochvíl, Lukáš (advisor) ; Šťáhlavský, František (referee)
Paroedura genus includes 17 described species endemic to Madagascar and the Comoros Islands, where they went through a significant adaptive radiation. The genus Paroedura is monophyletic and well supported hypothesis on phylogenetic relationships among its species was published. Species vary considerably in body size and morphology and in preferences for habitat, some species live in sympatry. The genus Paroedura belongs to cytogenetically poorly studied family Gekkonidae which exhibits high variability in modes of sex determination and in comparison with basal gecko lineages, also considerable variability in the chromosome number and morphology. Karyotypes of only two species of the genus (P. picta, P. sp.) have been published. The aim of my thesis was to describe karyotypes of both sexes in all available species of the genus using conventional and molecular cytogenetic methods, to perform the phylogenetic analysis of karyotype evolution and chromosomal rearrangements in the genus, to assess the role of these rearrangements in the speciation of the genus and to detect sex chromosomes. I acquired karyotypes of both sexes in nine species representing the most of major phylogenetic lineages of the genus. According to the results, species can be divided into three groups according to diploid...
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The role of hybridization in animal evolution
Šárová, Markéta ; Reifová, Radka (advisor) ; Černá Bolfíková, Barbora (referee)
There is a growing number of studies showing that interspecific hybridization and gene introgression have a creative role in the evolution of animals. These studies emphasize that hybridization and a gene introgression represent an important source of a genetic variability. Within the process of adaptive introgression, adaptive traits may spread among species and help them to colonize new environments. Interspecific hybridization may also contribute to the emergence of new phenotypes and evolutionary novelties and thus contribute to adaptive radiations. Hybridization can be also a cause of parallel evolutions in many organisms. Another way how hybridization affects evolution is related to a speciation. Hybrid speciation could be one of ways how new species arise, and in this way increase the biodiversity. However in many cases the hybridization has an opposite impact on species richness and present a danger of species extinction by hybridization. The aim of this bachelor thesis is to explain and discuss the above described processes, introduces selected examples of animals related to these processes, and finally evaluate the role of interspecies hybridization in animal evolution. Key words: interspecific hybridization, adaptive introgression, adaptive radiation, parallel evolution, hybrid speciation
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Molecular cztogenetic analysis of adaptive radiation in the gecko genus Paroedura (Squamata:Gekkota)
Koubová, Martina ; Kratochvíl, Lukáš (advisor) ; Šťáhlavský, František (referee)
Paroedura genus includes 17 described species endemic to Madagascar and the Comoros Islands, where they went through a significant adaptive radiation. The genus Paroedura is monophyletic and well supported hypothesis on phylogenetic relationships among its species was published. Species vary considerably in body size and morphology and in preferences for habitat, some species live in sympatry. The genus Paroedura belongs to cytogenetically poorly studied family Gekkonidae which exhibits high variability in modes of sex determination and in comparison with basal gecko lineages, also considerable variability in the chromosome number and morphology. Karyotypes of only two species of the genus (P. picta, P. sp.) have been published. The aim of my thesis was to describe karyotypes of both sexes in all available species of the genus using conventional and molecular cytogenetic methods, to perform the phylogenetic analysis of karyotype evolution and chromosomal rearrangements in the genus, to assess the role of these rearrangements in the speciation of the genus and to detect sex chromosomes. I acquired karyotypes of both sexes in nine species representing the most of major phylogenetic lineages of the genus. According to the results, species can be divided into three groups according to diploid...
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