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Vliv stavu a funkce imunitního systému na pohlavní výběr u ptáků
Vinkler, Michal ; Albrecht, Tomáš (advisor) ; Kleven, Oddmund (referee) ; Grim, Tomáš (referee)
Evolution is a most fascinating feature of all living things in our world. The means of organismal evolution are diverse, comprising mainly of natural and sexual selection. Both of these phenomena may contribute to evolutionary adaptations in health and disease. The questions of immunity impact on the process of sexual selection and sexual selection for increased anti-parasite resistance are wide issues of the present research in natural sciences. Their clarification requires multidisciplinarily-based investigation combining a variety of partial results into a single united paradigm. My co-workers and I have chosen several specific issues to study, in order to fill some of the important gaps of the current knowledge. We proposed the Carotenoid maintenance handicap hypothesis to point out that optimisation instead of maximisation of the carotenoid intake and ornamental display may be physiologically convenient for the individual. In Scarlet rosefinch (Carpodacus erythrinus) we confirmed the role of the carotenoid-based ornamental colouration in the process of sexual selection and investigated several partial aspects of the association between immunogenetics, immune function, health and the ornament expression and mate choice. In Zebra finch (Taeniopygia guttata) we have shown that the present way of...
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Sperm strategies in rodents
Šandera, Martin ; Stopka, Pavel (advisor) ; Macholán, Miloš (referee) ; Sedláček, František (referee)
Rodents exhibit diverse biology, mating systems and diverse sperm morphology. Different levels of sperm competition have therefore been found in this group. Generally, it is accepted that sperm competition in animals causes the prolongation of sperm tails. However, what other sperm morphological adaptations in rodents are affected by sperm competition? Species-specific sexual selection likely optimizes sperm morphology. Sperm physiology, morphology and competition may be influenced, ultimately, by environmental factors. This Ph.D. thesis focuses on sperm competition in murine rodents. The thesis contains three research articles (including one as a submitted manuscript). In addition, another published article, partialy related to the topic of this thesis, is represented in the Appendix. The sperm morphology in rodents plays an important role in sperm competition. Longer tails and apical hooks are usually found in the species with relatively larger testes and with higher percentage of multiple paternity (i.e. rate of promiscuity), that is in species with the higher risk of sperm competition. The goal of the first study was to investigate the relationships between relative testis weight and sperm traits (apical hook and tail lengths and variance in this traits). The apical hook length was positively...
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The association between tail streamer length and male atractiveness in barn swallows
Záleská, Josefína ; Albrecht, Tomáš (advisor) ; Cepák, Jaroslav (referee)
In the view of the sexual selection research, the barn swallow (Hirundo rustica), and its European subspecies (Hirundo rustica rustica) in particular, belongs to the most detailed studied bird species all over. The males of the European subspecies have in general markedly longer outer tail streamers than the females have and, based on research in several European populations, this tail ornamental trait plays an important role in sexual selection in this subspecies. The length of the tail streamers was found to be related to several main parameters that are connected to individual attractiveness in socially monogamous pairing systems, such as early partner acquisition and earlier nesting initiation date, the probability of repeated nestings in a breeding season or the number of successfully raised young. The main aim of the presented diploma theses is to assess to what extend is the length of the tail streamers a determinative trait related to male attractiveness in a South Bohemian population of the European barn swallow. The results of this thesis imply that the tail streamer length of males is, indeed, an attractive trait in this population, connected to multiple mating advantages. KEY WORDS Sexual dimorphism, sexual selection, barn swallow, nesting initiation, attractivity, reproductive success,...
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The role of imprinting-like effects and social learning for persistence of variability of iris and hair color in European population
Joudal, Lukáš ; Kleisner, Karel (advisor) ; Bártová, Klára (referee)
In bachelor's thesis I deal with the influence of various factors on the color of hair and eyes of the European population. In Europe, many still find blond and light eye colour population despite there is much darker colored populations. Here are some of the mechanisms causing maintain high polymorphism in the European population. The first part of bachelor's thesis focuses on a brief description of the structure of the European population. The thesis also discusses the genetic determination of hair and eyes, its diversity and the differences of the population from the populations of Asia and Africa. In the next section, we discuss the emergence and spread of recessive alleles light eye color a blonde in Europe, particularly northern Europe. The following is a description of the mechanisms influencing the propagation and conservation of recessive alleles. In the penultimate chapter describes the relationship between the morphology of the face and eye color, and the last chapter summarizes the effects mentioned in the previous chapters and their effect on the length of the relationship between partners.
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Nest construction
Jenšovský, Václav ; Kreisinger, Jakub (advisor) ; Šulc, Michal (referee)
The nest is in the life of birds important structure. It's a place where kept for posterity during the entire period of reproduction. For this to be nest offspring suitable place for development, must have a specific structure which is variable for each species. Variability, whether at the level of intraspecific and interspecific level and is influenced by several factors. These factors include thermal insulation properties, antipredatory properties, further property to protect the nest before (ecto) parasites, but also can design nest pose as a selectable character sexually. Each of those factors differently closer together, but often one factor may disadvantage second and thus reduce the success of rearing offspring. Key words: nest construction, thermal insulation properties, antipredatory properties, ectoparasites, sexual selection
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Social perception of trustworthiness and its projection in morphospace of human face: evolutionary and ecological consequences
Renzová, Šárka ; Kleisner, Karel (advisor) ; Varella Valentova, Jaroslava (referee)
Differences in perception of the human face is caused by variability in facial features, which stands in the face properties, such as attractiveness, dominance and trustworthiness. This literature review focuses on the perception of trustworthiness and its impact to social interactions. The attention is also paid to possible evolutionary mechanisms such as sexual selection. Moreover, this work deals with the neurohormonal causes in the perception of trustworthiness, wherein the subcortical brain region called the amygdala plays the main role. Keywords: perception, the human face, trustworthiness, the amygdala, sexual selection
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Perception of individual variation in body odour in human adults
Fialová, Jitka ; Havlíček, Jan (advisor) ; Schaal, Benoist (referee) ; Stopka, Pavel (referee)
The thesis consists of two parts. The first part introduces the topic of human chemical communication and reviews current evidence on individual variation in human body odour and its perception. This part is framed by sexual selection theory. In the first chapter, the concept of the theory of communication is introduced followed by a discussion on the specifics of chemical communication. Next, the formation of individually specific body odour signatures with reference to skin glands, their volatile products and the subsequent metabolization by skin microflora is described. The next chapters are dedicated to selected interindividual body odour cues such as sex and kin recognition, genetic compatibility in genes of Major Histocompatibility Complex, and health and reproductive status in a mate choice context. Furthermore, interactions between perfumes and body odours are discussed. Finally, methods of body odour sampling are introduced and a rationale behind presenting individual samples or body odour blends is discussed. The second part is comprised of six scientific papers, specifically three reviews and three empirical studies. Review papers summarize factors affecting human body odour quality with emphasis on diet and affective states. The first text shows that human body odours contain cues to...
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Association between human body odour and health status
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Vinkler, Michal (referee)
The subject of this thesis is to evaluate a link between changes in body odor and health status in humans. The main aim was to create a theoretical overview of the available studies concerning humans, which are compared with studies conducted on mammals. Alteration of body odor due to the ongoing disease may negatively influence not only the odor attractiveness of a potential partner, but also may cause changes in behavioral response to a chemical stimulus for other members of the species. One may assume formation of perceptual adaptations exhibiting sensitivity to markers of health status in both sexes. Recognition of ill individuals may be crucial during social interactions, to prevent transmission of pathogens, but in mate choice the health status may also serve as an important indicator of resistance to infection, which can affect the viability of the offsprings. The main contribution of this thesis is to summarize the knowledge and insights into the area related to changes in body odor, depending on the health status. Keywords body odor, health, sexual selection, attractiveness, olfactory perception
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Oxidative stress and condition-dependence of ornamental signals of quality in socially monogamous songbird
Valášek, Stanislav ; Tomášek, Oldřich (advisor) ; Sedláček, Ondřej (referee)
6 ABSTRACT Conditional ornaments plays irreplaceable role in sexual selection in non-small part of by sexual reproduction reproducing animals. Fastidiousness of generating and later also carrying of these ornaments which show condition of their wearer, burdens also metabolism in non-small scale. This thesis tests hypothesis of mutual addiction between conditional ornaments, as the indicators of qualities of individuals and metabolism, as the most significant source of free radicals which are responsible for oxidative stress. The real weight of influence of ornament fastidiousness on organism, resp. on redox state, is tested in this thesis. Manipulations which were performed with individual males of model species should point how much the selected factors correlate each other. The barn swallow (Hirundo rustica) is the model species. Analyses of dates collected during trapping which were realized in breeding seasons in 2012 and 2013 does not show any important trends between observing variables. This fact is confirmed by minimal differences and inconsistent variability of levels of measured antioxidants - oxidoreductases, superoxide dismutase and glutathione peroxidase. The marginal effect of manipulations with one of the conditional ornaments which are presented in model species supports the hypothesis of...
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