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Transformation of trace element speciation in disturbed soil profile
Kochergina, Yulia ; Mihaljevič, Martin (advisor) ; Vaněk, Aleš (referee)
Distributions of toxic trace elements were studied in soils before and after disturbation of their profiles.Two areas with different vegetation cover were selected: beech (Fagus sylvatica) and spruce (Picea abies) forests at the Načetín site in the Ore Mts. In the past, this area belonged to places with extreme levels of acidic atmospheric deposition. The studied areas are not placed too far from each other and have thus approximately the same climatic conditions, geological background and pollution input. On the other hand, physicochemical properties of soils (pH, CEC, BS, Ctot, Stot) and concentrations of major and trace elements are different. At selected sites in spruce and beech stand, two soil probes to a depth of 40-50 cm were dug in 2010 and samples of individual soil horizont were collected for chemical analyses (approximately 0.5 kg). Four samples from L, H, A and B horizons were taken in the spruce forest area and five samples from L, H, A, B and C horizons were taken in the beech forest. In 2011, the sites were re-sampled and samples were taken from horizons that were disturbed in 2010, paralleled by samples of undisturbed soil horizons from the same probe sites. Trace element concentrations were determined by ICP-MS, the speciation of individual elements in the soils was determined by...
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Parental conflicts and speciation in the house mouse
Kropáčková, Lucie ; Reifová, Radka (advisor) ; Macholán, Miloš (referee)
Hybridization between closely related species of mammals is often accompanied by abnormal growth of placentas and fetuses. From the perspective of evolutionary biology, our knowledge about the contribution of such interspecies incompatibilities in speciation is still insufficient. In my thesis, I was finding out if abnormal placental and fetal growth contributes to reproductive isolation of two subspecies of house mouse, Mus musculus musculus and M. m. domesticus, which are at an early phase of speciation and in nature they still hybridize. Using two inbred strains derived from M. m. musculus (PWD/Ph, STUS) and two inbred strains derived from M. m. domesticus (C57BL6/J, SCHEST) we performed four different intrasubspecies and four different intersubspecies crosses. We found out that the size of the placenta in hybrids is more influenced by father, while the size of the fetus is more influenced by mother. After elimination influence of weight of mother and father we have not recorded a significant difference in the size of placentas and fetuses in intrasubspecies and intersubspecies crosses. Our results show that hybridization between subspecies of house mouse does not produce abnormalities in prenatal development, as was observed in hybrids between distant species of mice. It is thus possible that...
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Concept of species in bears (Ursidae): practical, historical, and theoretical viewpoint
Wagner, Jan ; Fejfar, Oldřich (advisor) ; Sabol, Martin (referee) ; Musil, Rudolf (referee)
The present thesis surveys topic of taxonomic diversity and phylogeny of bears (Mammalia, Ursidae) and aspects of its contextual setting under effects of changing conceptual and methodological viewpoints. This problem is studied from several perspectives. The historical perspective is represented by a critical overview of the history of specific and infraspecific classification of bears with special respect to mutual influences of this classification and theoretical concepts of species accepted in particular periods. The perspective of material approach is exemplified by a material-based study of taxonomical and phyletic status of selected Pliocene to Middle Pleistocene ursine taxa. Along with deconstruction of some traditional hypotheses this produced a model explaining species diversification in ursine bears and its discussion in terms of factual relevance of included background concepts. In the pre-evolutionary period the bear species were usually understood broadly, as incipient immanent entities, yet exhibiting obvious certain infraspecific variability. This was established using definitions of varieties (mostly not identifiable with present subspecies or infraspecific taxa) considered as unstable modes of particular species. Although, in the post-Darwinian period, the concept and taxonomic...
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Latitudinal gradient of biodiversity and its dependence on rate of ecological processes and evolutionary processes
Krupička, Jan ; Storch, David (advisor) ; Kubička, Lukáš (referee)
Unevenness in the distribution of species diversity on the surface of the earth is one of the most striking phenomena in ecology. Latitudinal gradient of biodiversity could be explained by different rates of evolutionary processes such as speciation and ecological processes that control the ratebof extinction. The goal is to collect and evaluate the literature on the temperature dependence or latitudinal trends in the rates of these processes. Matabolic theory of biodiversity serves as the best explanation of the rates of evolutinary processes and their dependance on temperatur, while an explanation of the rate of ecological process is lacking in empirical data and theories that would put them in relation to temperature and latitude. Explanation by More individual hypotheisis was proved unconvincing.
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Sources of Sorbus aria agg. variation
Bílá, Jana ; Urfus, Tomáš (advisor) ; Chumová, Zuzana (referee)
Genus Sorbus is a very complex group of vascular plants. Various genetic lineages which can be fixed by apomixis are driven by interspecific hybridisation and polyploidy. Species from S. aria agg. have the highest variation probably due to an extra mechanism - introgressive hybridisation. There are several concepts of the aggregate which are usually based on three main species: S. aria, S. umbellatta and S. graeca. Therefore, new microspecies are derived by genome doubling and hybridisation between the main species. Units of the aggregate are assessed differently as the distinction of taxa is very complicated due to the overlap of the morphological variability. The aggregate itself can be sometimes considered as a category for species of uncertain origin or identification. Four species from S. aria agg. occur in the Czech Republic. In addition, the conclusion offers questions that will be addressed in the master's thesis.
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The factors affecting evolutionary diversification
Černá, Vladimíra ; Storch, David (advisor) ; Kratochvíl, Lukáš (referee)
The number of species on the Earth is estimated to lie between five to ten millions. All these species originated from a common ancestor, which appeared on our planet 3,5 bilion years ago. Speciation and extinction are responsible for the current species richness. Evolutionary diversification is the difference between speciation and extinction. There are several methods used to obtain the values of speciation, extinction and diversification rates. I will briefly explain some of these methods, outline the advantages and disadvantages of them. The aim of this paper is to summarize current knowledge of evolutionary diversification and factors that may affect it. In this search I focused on the studies dealing with factors that may affect several groups of organisms. Although many determinants of diversification were found, most of them affect only one group of organisms. Here I did not find any factor that would be common for the majority of taxa. Evolutionary diversification is probably influenced by different factors in different evolutionary lineages. Key words: diversification, speciation, radiation, diversity gradient
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Interspecific hybridization in Acrocephalus warblers.
Majerová, Veronika ; Reifová, Radka (advisor) ; Kotlík, Petr (referee)
Acrocephalus warblers have gone through the adaptive radiation during last severalmillion years, which gave rise to thirty one species occupying mainly Eurasia,Africa and Australia. The majority of species are morphologically very similar,however, they differ in ecological requirements, migration strategy, and song.Interspecific hybridization seems to be quite common among Acrocephaluswarblers, not only between sister species, but also between more distantly relatedtaxa. The main goal of this study was to determine whether this hybridization leadsto gene flow between species and which factors affect the rate of interspecific geneflow. For this purpose we conducted population-genetic analysis in three Europeanspecies of the Acrocephalus warblers of the subgenus Notiocichla: reed warbler (A.scirpaceus), marsh warbler (A. palustris), and blyth's reed warbler (A. dumetorum).Our results based on the analysis of sequence data from eight nuclear loci indicate,that gene flow between the studied species occurs, but only in one direction. Thegene flow is higher between genetically more related species than betweenecologically more similar species. We also estimated that the reed warbler and themarsh warbler diverged approximately 1,1 million years ago. The blyth's warblerand ancestor of the reed and marsh warbler...
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Speciation Analysis of Mercury concentrated on Selective and Sequential Extraction
Martinovský, Václav ; Mihaljevič, Martin (advisor) ; Holý, Martin (referee)
This bachelor thesis deals with methods of speciation analysis of mercury concentrated to selective and sequential extraction of mercury. The first part contains the basic information about characteristics, sources of pollution, toxicity and cycle of mercury in environment. The following part defined term of speciation and speciation analysis. Next chapters are concentrated to description and characterization appropriate and often used extraction reagents and procedures and schemes of selective and sequential extraction methods of speciation analysis. Specific procedures of SEA are described in this thesis and mentioned are their major advantages nad purphose. The last chapter is devoted to listing methods of instrumentation useful to determination of extractable forms of mercury.
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Speciation and isotopic composition of lead in coal samples from selected profile of the Most Basin
Semíková, Hana ; Chrastný, Vladislav (referee) ; Strnad, Ladislav (advisor)
Coal is one of the major energy sources in the world and contains most of the elements from the periodic table. During combustion of coal these elements are released and redistributed. This may lead to environmental problems. Some of these elements are considered to be very dangerous for human and animal health and ecosystems. The knowledge of concentration and speciation of elements in coal is important for the prevention of the adverse environmental phenomena associated with the use of coal. One of the hazardous elements in coal is lead. The purpose of this work is to determine the concentration of lead and its isotopic composition simultaneously with determining the speciation of lead in coal. The ICP-MS method was used to determine the concentration and isotope ratios of lead. A total of 62 samples of subbituminous coal was analyzed. The method of selective extraction analysis BCR was used on 9 samples of subbitumnious coal to identify the speciation of lead in coal. Lead concentrations in coal were measured in the range of 0.25 to 78.84 mg·kg-1 . These concentrations correspond to the average concentrations of lead in most of the coals. Isotope ratio 206 Pb/207 Pb in coal samples ranged from 1.169 to 1.219. Isotopic 208 Pb/206 Pb ratio was measured in the interval 2.047 to 2.093. The isotopic...
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