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Extinction risk and population size
Váňová, Lenka ; Storch, David (advisor) ; Reif, Jiří (referee)
There is generally accepted assumption that the probability of extinction risk increases with decreasing population size. But it's not sure at all, to what extent does this relation really work in real populations. The amount of studies dealing with this topic is on the increase, but still it's necessary to carry on researching. Previous results indicate that inspected connection is indeed true in many populations, in other words, preferential extinction of less abundant populations functions properly. Yet the dependence isn't as unambiguous and strong as expected. Many exceptions are known as well, which demonstrate that low number of individuals doesn't always have to be a disadvantage in terms of survival chance. Such deviations can be found both in paleontological papers and among current populations. For example, mass extinctions represent that kind of a special exception because each of them was probably driven by a different mechanism, so in one case the abundance could be an advantageous trait, whereas in another it was rather disadvantage. In my work, I briefly mention themes referring to extinction in general and subsequently I try to summarize findings about the phenomenon of population size and its connection to extinction risk. On the basis of explorers' ideas and by means of...
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Mountains as islands
Kačabová, Petra ; Storch, David (advisor) ; Ferenc, Michal (referee)
In this paper I deal with island biogeography and its applicability to isolated mountaintops, as an ecological equivalent of true islands. I discuss both true and mountain islands regarding their origin and the influence of long-term climate evolution on Earth. I underline some features of mountain islands, resulting from their topography and the dissimilarities of both types of island barriers. I find that mountain and true island communities might or might not have a number of species in a state of equilibrium, caused by balance between species immigration on island and their extinction. If the number of species on island is not in equilibrium, species extinction is not balanced by species immigration. I consider patterns of island communities, mainly nestedness, which has been frequently studied on mountain, as well as true islands. I discuss distribution patterns concerning invertebrates. And finally, I concentrate on recent methods of moutain island research and discuss mountain island isolation issues in terms of global warming.
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Limitation of species richness
Szostoková, Kateřina ; Storch, David (advisor) ; Šímová, Irena (referee)
Currently we can find two main hypotheses of diversity dynamics in time in literature - bounded and unbounded hypothesis. According to bounded hypothesis diversity is limited, while unbounded hypothesis says that there are no obvious limitations of diversity. Evidence for these main hypotheses comes mainly from paleontological research, studies of phylogeny and comparison of local and regional diversity. None of these approaches give us clear and incontrovertible evidence of diversity limits. The aim of this work is to show some evidence that confirm (or not) limitation of diversity in mentioned kinds of biological research. Also, I would like to point out some critics and imperfections of used methods.
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Proposal for Debt Collection Improvement in the Enterprise
Gerlichová, Veronika ; Kyrych, Vladimír (referee) ; Musilová, Helena (advisor)
Bachelor thesis focuses on the suggestions for the improvement of security systems and debt collection for the selected entrepreneur. Specifies the basic theoretical information on legal, accounting, taxes and economics. In the analytical part is the entrepreneur briefly introduced and evaluated his current state of receivables. An integral part is also putting theory into practice by any proposals for tackling the problem.
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Latest Ludlow chitinozoans from the Prague Basin: significanec for correlations and succession during Kozlowskii/Lau extinction events
Vodička, Jakub ; Fatka, Oldřich (advisor) ; Štorch, Petr (referee)
Two sections, Všeradice and Kosov, represent continuous sedimentary succession situated in the Prague Basin. No detailed research on stratigraphical level equal the N. kozlowskii graptolite zone focusing on chitinozoans, has not yet been conducted in the Prague Basin and is also very scarce globally. Limestone beds, examined for chitinozoans, were not very productive. Chitinozoan reaction on extinction is visible, if we compile data from both sections. The pre-extinct chitinozoan fauna is characterized by the Conochitinidae family. Samples from the post-extinct interval contained no chitinozoas. The interval of fauna recovery is characterized mainly by the Eisenackitina genera. In this interval, global zone for the uppermost Ludfordian, represented by E. barrandei, can be confirmed. In agreement with all the published literature, we have not found E. philipi, index taxa of the former global zone in the Prague Basin. E. lagenomorpha appears stratigraphically only slightly below E. barrandei and therefore it cannot substitute E. philipi, as it is used in Baltika region. chitinozoa, Prague Basin, Kozlowskii, Lau, extinction, Ludfordian, stratigraphy
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Development of the mammal assemblages during Quaternary climatic changes
Havlová, Tereza ; Mazuch, Martin (advisor) ; Nývltová Fišáková, Miriam (referee)
During the Quaternary there was a cyclical alternation of warm and cold periods - interglacials and glacials. Over the past 2.5 million years there was eighteen or twenty these cycles. These climate changes influenced by, except other, Milankovic cycles caused at sea level, extent of glaciation or distribution of vegetation zones. All these factors affected the communities of mammals, their distribution, migration and extinction of some groups of mammals. Area of continental and mountain glaciers expanded as well as levels of the ocean decreased during the glacials. Many species of mammals penetrated into new territory with the emergence of land-bridges a mammals from isolated areas could interact during cold periods. There was a retreat of glaciers and sea level rise and the migration routes through the land bridges was interrupted during the interglacials. Many, mostly island, populations were isolated and they were often developed to new endemic species. Key words: glacial, interglacial, climate changes, distribution, migration, extinction
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Vliv fragmentace a ztráty habitatu na primáty
Sniegon, Arthur F. ; Sedláček, Ondřej (advisor) ; Pluháček, Jan (referee)
Anthropogenic activities and human encroachment may cause profound and often irrevocable changes in an environment. This may result in challenges for most of the wildlife, including our closest extant relatives, non-human primates. Worldwide, primates may be particularly susceptible to human-induced habitat alterations owing to their large body size, social way of life, slow reproduction, large home-ranges, naturally low population densities and often strong dependence on forest cover. Three main phenomena have been described as major threats for primates: loss of the natural habitat and its conversion to human-dominated landscape, fragmentation of the remaining patches of suitable habitat, and commercial bushmeat hunting. Here I review the first two processes. If primates survive the initial disturbance, they are forced to adjust their demographic, behavioural and dietary traits. However, this may not be enough for their persistence in a long term as their genetic diversity might be compromised. Moreover, also parasitic infections may impact severely the disrupted populations. In this thesis, I reviewed the current knowledge in primates demography, population genetics, dietary changes and parasite interactions in altered habitats. Most of the studies examined the African continent and Latin America, a...
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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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The House
Žilinský, Michal ; Zálešák, Jan (referee) ; Mikyta, Svätopluk (advisor)
The house, which has been influencing me since my childhood by its peculiarity is now beeing consumed by vegetation and the ceilings in the interiors are starting to collapse. Termination of romantic settings brings me back to the source of my influences and inspirations – relics of which authenticity I mold into the drawings as fossilized artifacts and black and white documentary video scenes that attest to the aging of the setting in real time.
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Economic Impacts of Winding Up a Company with Liquidation
Švandová, Kateřina ; Kramolišová, Eva (referee) ; Pernica, Martin (advisor)
The thesis deals with legislative aspects of the abolition of corporate insolvency and dealing with the expression of the economic consequences arising from the demise of the organization to key stakeholders (employees, state, creditors). The theoretical part deals with basic concepts related to corporate, legal forms of business characteristics, causes and forms of dissolution and its subsequent liquidation process. The practical part focuses on the company, joint stock company, which is in liquidation and the economic consequences arising from the termination of the business activities of this company for state employees and creditors of the organization.
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