|
|
Phytophily - its origin and influence onto humans
Hůla, Martin ; Komárek, Stanislav (advisor) ; Kleisner, Karel (referee)
Phytophilia, the love of plants, is a widespread and probably inborn human quality. This work shows evolutionary interpretations of its origin. These suggest that phytophilia has evolved as an adaptation to the choice of the resource-rich habitat and to the effective orientation in space. The work also presents the effects of plants on human psyche and briefly mentions cultural and individual differences.
|
|
|
Biological research in ultraviolet spectra: evolutionary and eto-ecological implications of UV reflectance in organisms
Pecháček, Pavel ; Kleisner, Karel (advisor) ; Hotová Svádová, Kateřina (referee)
Many species have surface patterns capable of reflecting ultraviolet light. The presence of UV reflecting markings on invertebrates (e.g. beetles, spiders, and butterflies) and many vertebrates has been proven by numerous studies. In my work, I lay a particular stress on Lepidoptera and, within the vertebrate taxon, on birds. The existence of UV reflecting surfaces on fish and reptiles and consequent questions are also mentioned. The aim of my work is to summarize all existing knowledge about UV reflectance, and to discuss its significance for subsequent research. My work also deals with the function of the UV textures, mainly in sexual selection, intra- and interspecies signaling and in foraging behaviour of the studied taxa. The last section touches those groups which do not reflect the ultraviolet light but are visually sensitive to it, e.g. certain kinds of zooplankton, amphibians and small mammals. The resulting summary shows a great significance of UV reflecting textures in various branches of biology and their importance in ecology and evolution of many species.
|
|
|
Effects of multimodal warning siglals of Tritomegas sexmaculatus on reactions of bird predators
Binderová, Jana ; Exnerová, Alice (advisor) ; Kleisner, Karel (referee)
Aposematic animals advertise their defensive mechanisms to potential predators using warning signals. Signalling through more than one sensory pathway is called multimodal warning display. Most experimental studies of aposematism have been focused on the effect of a particular warning signal rather than on importance of multimodal signalling. Focusing on the multimodal signalling of real prey is the best way how to understand its effect in nature. The present study is focused on comparing the effect of multimodal warning display of insect prey with its particular warning signals on two species of bird predators. Multimodal warning signalisation of the burrowing bug, Tritomegas sexmaculatus consists of visual (black and white coloration), chemical (odour, possibly taste) and acoustic (stridulation) signals. We compared reactions of wild-caught great tit (Parus major) and blue tit (Cyanistes caeruleus) to three types of bugs with different warning displays. The non-manipulated bugs displayed multimodally, the brown painted bugs had their warning coloration manipulated and the dealatized bugs couldn't emit acoustic signals. The wild-caught birds of both species avoided all types of bugs. In an experiment with naive hand reared great tits we compared their reactions to non-manipulated and dealatized bugs. Naive...
|
|
|
Antipredatory function of flash display in Heteroptera (case of Coreus marginatus)
Pipek, Pavel ; Exnerová, Alice (advisor) ; Kleisner, Karel (referee)
1 Abstract Aim of the present study was to test antipredatory function of fulguration (or flash display), which means sudden exposition of conspicous body part on otherwise cryptic animal during escape. Adult squash bugs (Coreus marginatus; Heteroptera) were used as model prey, while as model predator served two species of passerine birds - blue tit (Cyanistes caerulus) and great tit (Parus major). Three approaches were undertaken. Test of palatability should have assessed the efficiency of squash bug chemical defence against bird predators. Experiment was carried out in experimental cage without interference of experimenter and without occurrence of fulguration. The results show that chemical defense of squash bug is less efficient than defense of other species of true bugs (Pyrrhocoris apterus, Graphosoma lineatum) and that the efficiency differs between two generations of squash bugs. In the test of efficiency of fulguration, the prey was forced by experimenter to fly in response to bird attack. Blue tits attacked the immobile prey more often than the flying and fulgurating one, but the same relation wasn't significant with great tits. The latencies of birds' returns to the bugs that landed after fulguration wasn't influenced by colour of the bugs' abdomen. Third experiment consisted of computer...
|
|
|
Industrial melanism in the context of ultraviolet reflectance
Stella, David ; Reif, Jiří (referee) ; Kleisner, Karel (advisor)
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.
|
|
| |
|
|
Biological meaning and cultural role of human eyes and iris color
Hořejší, Johana ; Hladký, Vojtěch (referee) ; Kleisner, Karel (advisor)
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.
|
|
| |
|
| |
|
|
Biosemiotics
Buchta, Martin ; Kera, Denisa (advisor) ; Kleisner, Karel (referee)
Biosemiotics - study of living systems from a semiotic perspective. Semiotic perspective on living nature in tradition of general semiotics of C. S. Peirce. Sign is a biological adaptation of useful function (pragmatism). Every organism is a sign, and its life cycle is a continuous process of self-interpretation. Semiotic approach as candidate for new paradigm (T. Kuhn) in biology. The role of observer - animals as interpreters of their environment. Umwelt - subjectively interpreted environment (Uexküll). Umwelt is the semiotic world of organism, unites all semiotic processes of an organism into a whole. Organisms are autonomous agents (S. Kauffman) living in their own semiotic Umwelt. Semiotic mechanisms are embedded in a semiosphere (Lotman). Semiosphere is the set of all interconnected Umwelts. Signs are created and shared inside semiosphere. Extended concepts of knowledge, meaning, interpretation, and subject - applicable to both human and non-human actors (autonomous agents). Genes play a dominant role in evolution. Difference between genes (genotype) as information and DNA (material). Organisms as self-reading texts. Symbiotic evolution of organism. Organic codes.
|
guest ::
