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Temperate flora of Patagonia and specific points of its evolution
Koubek, Matěj ; Ptáček, Jan (advisor) ; Šrámková, Gabriela (referee)
Patagonia is one of the few regions in the Southern Hemisphere with a temperate climate, and therefore provides a unique environment for studying the evolution of the local flora. Patagonian plants, like their temperate counterparts in the Northern Hemisphere, show higher rates of polyploidy. Polyploidy is a widespread condition among plants that plays a key role in the adaptation of species to various extreme stress conditions. Climatic characteristics, glaciations or volcanic activity, for example, are factors influencing the distribution of organisms. This work focuses on the study of the Patagonian flora, in particular on alpine and steppe species and their biogeography in relation to the climate and geology of the area. It also discusses the relationship between polyploidy and this distribution. Specifically, this work focuses on the widely distributed model species Azorella prolifera, which exhibits three ploidy levels. However, we have zero knowledge of the occurrence of individual cytotypes. The distribution and properties of polyploids have not been studied to a sufficient level in the Southern Hemisphere. Only a fraction of the papers dealing with this issue focus specifically on Patagonian plants. A more comprehensive insight into this topic may lead to a better understanding of the...
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Evolutionary processes underlying plant diversification in the tropical Andean highlands
Aparicio Vásquez, Diana Libeth ; Sklenář, Petr (advisor) ; Hughes, Colin (referee) ; Šmarda, Petr (referee)
The highlands in the northern Andes, which are known as the páramo, are recognized worldwide for their unique and species-rich flora. Many páramo plant groups underwent radiations, which have been shown to be very recent and outstandingly fast. These radiations have usually been linked to (1) the uplift of the northern Andes, which provided new ecological opportunities in the highlands that originated in this process, (2) Quaternary climate change that produced range shifts of the páramo, resulting in periods of páramo contraction and isolation, during cold periods, and periods of páramo expansion and connection, during warm periods (3) the Andean physiographical and ecological heterogeneity, which provides extent oppornuties for isolation and for ecological divergence. In spite of increasing research efforts to understand the evolution of the páramo flora, the actual processes underlying species diversification remain unclear. The main aim of this thesis is to contribute to the understanding of these processes. We use three different approaches in two different study systems: (1) A population genetics approach, which remains rare among páramo plant studies, focuses on three páramo Lupinus species (Lupinus alopecuroides, L. nubigenus, L. microphyllus). These species belong to one of the best...
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Evolutionary processes underlying plant diversification in the tropical Andean highlands
Aparicio Vásquez, Diana Libeth ; Sklenář, Petr (advisor) ; Hughes, Colin (referee) ; Šmarda, Petr (referee)
The highlands in the northern Andes, which are known as the páramo, are recognized worldwide for their unique and species-rich flora. Many páramo plant groups underwent radiations, which have been shown to be very recent and outstandingly fast. These radiations have usually been linked to (1) the uplift of the northern Andes, which provided new ecological opportunities in the highlands that originated in this process, (2) Quaternary climate change that produced range shifts of the páramo, resulting in periods of páramo contraction and isolation, during cold periods, and periods of páramo expansion and connection, during warm periods (3) the Andean physiographical and ecological heterogeneity, which provides extent oppornuties for isolation and for ecological divergence. In spite of increasing research efforts to understand the evolution of the páramo flora, the actual processes underlying species diversification remain unclear. The main aim of this thesis is to contribute to the understanding of these processes. We use three different approaches in two different study systems: (1) A population genetics approach, which remains rare among páramo plant studies, focuses on three páramo Lupinus species (Lupinus alopecuroides, L. nubigenus, L. microphyllus). These species belong to one of the best...
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Anatomy and functional ecology of tropical alpine plants in South America
Gorčicová, Barbora ; Sklenář, Petr (advisor) ; Stančík, Daniel (referee)
The bachelor thesis discusses the plants in the páramo. The first part describes unique environment located at high altitudes of the tropical South America, the páramo. The uniqueness of the environment is caused by several basic conditions. The most important ones are significant daily temperature fluctuations, tropical climate stability during the whole year and high altitude. Anatomy of adapted plants, discussed in the second part of this work, conform to the extreme conditions. There are specific páramo life forms thanks to the uniqueness of the environment. The leaf structure and the vascular system of the plants are significantly modified in terms of anatomy. Although there are quite specific (and therefore interesting) life forms in the páramo, the current knowledge of the plant anatomy is minimal. The last part of the thesis suggests the questions for my future master thesis, which will contribute to better understanding of this underexplored topic.
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Phylogeny and biogeography of Neotropical and African riverine cichlids: multilocus phylogenetic methods in the evolutionary studies
Musilová, Zuzana ; Novák, Jindřich (advisor) ; Bryja, Josef (referee) ; Reichard, Martin (referee)
Summary: The thesis comprises from the introduction and five main parts: three of them are published papers, the rest two are manuscripts prepared for submitting to the scientific journals. The first two are published phylogenetic studies of the cichlasomatine cichlids based on (1) molecular characters, and (2) both morphological and molecular data with the description of a new genus Andinoacara. The third (3) is the already published description of the new species Andinoacara stalsbergi from Peru combining both morphological and phylogenetic approaches and including the detailed phylogeny of the genus Andinoacara. The next unpublished manuscript (4) is the more detailed comprehensive phylogeography of the two non-relative genera (including Andinoacaras) of the trans-Andean cichlids. Including all valid species from the majority of their distribution areas it was reconstructed the ancestral area of both genera in the Choco region, Colombia, and revealed the directions of their distribution spreading. The last (5) unpublished manuscript is the phylogeographical study of the cichlid genus Serranochromis from the headwaters of the totally unknown Central Angola. It showed several evidences of the faunal exchange among the adjacent river systems. Lastly, the thesis is supplemented by several appendices...
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