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Industrial melanism in the context of ultraviolet reflectance
Stella, David ; Kleisner, Karel (advisor) ; Reif, Jiří (referee)
This work focuses on the topic known as industrial melanism. The main aim of this thesis is to summarize the knowledge published on this topic. The first mentions about industrial melanism appeared in England in the end of 19th century. Many different hypotheses emerged during the last one hundred years. The work starts with introduction of the fundamental theory of industrial melanism in the context of environmental change during last three hundred years. Furthermore, the historical development of ideas on industrial melanism is given and contemporary hypotheses are discussed. Significantly, work deals with the biological role of UV reflectance in the context of industrial melanism.
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Semantic function of the mammalian tail in the design of anal pole of the body
Baxa, Marek ; Komárek, Stanislav (advisor) ; Kleisner, Karel (referee)
The tail in mammals is an important organ, which in contrast to most vertebrae, doesn't add to the motor function of their bodies. The use of the mamals' tail is much more varied and it can fulfill many different functions. This work includes a survey of these functions and analyzes collected data concerning 553 spieces of mammals across all families. The data includes information about the length of tail, the length of body, body mass, living environment and outer signs on the anal pole of these species. The resulting analysis concludes that the tail length is dependent both on the length of the mammal's body and its living environment. Outward signs of the tail depend on its length as well as the length of the body and the living environment. Distinctive tail ending and tail base probably fulfill a communicative function. The tail is more likely to have communication than cryptic significance.
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Biological meaning and cultural role of human eyes and iris color
Hořejší, Johana ; Kleisner, Karel (advisor) ; Hladký, Vojtěch (referee)
This study focuses on biological and cultural role of human eyes with respect to variation of iris color. It concerns evolution, genetic determination, and anatomy. It studies possible relationships between eye color and predisposition to diseases. Besides biological aspect, it deals with eye as an indicator of attractiveness and tendency to some types of behavior. It also outlines the role of eye in folklore and alternative medicine.
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Ecological factors influencing variability of ultraviolet colouration of flowers
Zitko, Martin ; Kleisner, Karel (advisor) ; Neustupa, Jiří (referee)
Ultraviolet colouration of flowers varies both among and within species. The significance of these patterns and differences among them was usually associated with a visual per- ception of pollinators. In this study we examine the variation of marsh marigold's (Caltha palustris) bull's-eye pattern on a basis of 289 observed individuals from 32 distinct locati- ons. The variation of this pattern is shown to be quite large within separate locations and the pattern is predictably changing according to latitude. This trend of darker colouration towards the equator is an another example of a more widely understood Gloger's rule in the plant kingdom. The effect of ultraviolet radiation appears to be one of the most likely causes of this phenomenon. Hereafter we analyse the weakness of this explanation, the gaps in current knowledge and propose possible directions of further research. Keywords: ultraviolet, bull's-eye, marsh marigold, Caltha palustris, Gloger's rule
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Environmental influences on the shape of ultraviolet signals in genus Gonepteryx (Lepidoptera, Pieridae).
Pecháček, Pavel ; Kleisner, Karel (advisor) ; Zapletalová, Lenka (referee) ; Vrabec, Vladimír (referee)
Like many other animals, butterflies are able to visually perceive the ultraviolet (UV) light; many species even have patterns on their wings which are visible in this part of the electromagnetic spectrum. Over the last forty years, it has been shown that these UV patterns play an important role in behaviour of many butterflies, especially in relation to sexual selection - they are involved in the process of recognising a suitable mate, and likely can signal some of the mate's qualities, such as its age, ability to handle stressful environmental factors, or efficiency in foraging. The patterns may also be used for taxonomical purposes. This dissertation thesis contains a comprehensive research into ultraviolet patterns of the Gonepteryx brimstones, with a primary focus on the issue of environmental influences in relation to the expression of these traits, on the patterns' potential role in sexual selection, or on their evolution. It has been successfully demonstrated that UV patterns of at least some Gonepteryx species are affected by the environment to a strong degree, significantly more than the traits not involved in sexual selection. On the whole, the conclusions made by submitted publications suggest that UV patterns play a role in the sexual selection of the chosen brimstones, though it is not clear...
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Cross-cultural perception of attractiveness and its correlates: the role of visual modalities
Fiala, Vojtěch ; Kleisner, Karel (advisor) ; Třebický, Vít (referee)
This work reviews the literature on the topic of intercultural perception of human attractiveness with special focus on recent videostimuli-using research. The first section introduces several basic perspectives on ecological-evolutionary view of attractiveness. The next section deals with intercultural differences in attractiveness perception dicussing possible explanations of these differences. The third chapter focuses on faces of people of cross-culture origin and usage of composite stimuli and artificially manipulated stimuli in inter-cultural research. The fourth chapter examines the usage of videostimuli in attractiveness research. I also add information about intercultural usage of videostimuli as far as these are available. Finally, I discuss a possible source of result ambiguity and highlight the potential use of videostimuli in intercultural research of attractiveness perception. Keywords Attractiveness, intercultural perception, videostimuli, cross-culture origin, composite images, averageness, masculinity, feminity
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Effects of colour, shape, and pattern contrast of prey on discrimination learning in avian predators
Kišelová, Martina ; Exnerová, Alice (advisor) ; Kleisner, Karel (referee)
Aposematism is a phenomenon in which noxious animals signal their unprofitability to predators by using conspicuous and contrasting visual signals. These visual signals are composed from several components, with the most important being bright colours and contrasting internal patterns. To compare the difficulty of several discriminative stimuli that consist with components of aposematic warning colouration in live animals, experiments were conducted with naive and adult Great Tits (Parus major). The Great Tits were presented with artificial prey, in the form of paper bugs, with the use of a sequential discrimination task; the bugs used differed in colour, shape or internal contrast. Each of the components were tested separately to ensure that the learned or unlearned discrimination task was dependant on the difficulty of the component. The results showed that the birds learned discrimination task when they could use colour or contrast as a cue but if the cue was shaped, they were not successful. These results support the hypothesis that the obvious discriminatory element was colour. Nevertheless, a surprising result emerged when using the discriminatory element of contrast as it was believed that birds are unable to learn the task if they can discriminate only by one contrast. This study not only...
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