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Ecology of the pathosystem of anther smut on Dianthus carthusianorum
Koupilová, Klára ; Koubek, Tomáš (advisor) ; Dostál, Petr (referee)
Anther smuts (Microbotryum violaceum s.l.) represent a well-known system for studying pathogens of wild plants and coevolution between pathogens and hosts. Infected plants produce sterile flowers with anthers filled with fungal spores which are transmitted to other host plants by pollinators. Data from existing research come mainly from the genus Silene. However, the applicability of these findings to other host plants of anther smuts is largely unknown. Therefore, this thesis focuses on a different host species - Dianthus carthusianorum. First, the pattern of disease was surveyed in natural populations of D. carthusianorum in a small area in Střední Povltaví. Most populations were infected to various degrees and only a few populations remained completely healthy. The prevalence of disease was positively correlated with size and density of host populations. On the other hand, environmental factors and the degree of connectedness had very little effect on disease prevalence. Second, additional data were collected from a subset of populations to determine plant resistance and densities of pollinators. Differences in resistance among populations (as inferred from flower inoculations) were not significant. Populations differed in densities of pollinators, but there was no correlation between densities...
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Visual cues in the coevolution of brood parasite and its hosts
Šulc, Michal ; Honza, Marcel (advisor) ; Fuchs, Roman (referee) ; Samaš, Peter (referee)
Avian brood parasitism is an ideal system for the study of coevolution. Brood parasites and their hosts have developed interesting adaptations during co-evolution allowing them to maximize their fitness. The evolution of these adaptations has a character of an "arms race" where the evolution of one trait in the host is tied with the evolution of another trait in the parasite. In my doctoral thesis, I deal with two of these adaptations: recognition of parasitic eggs by hosts and mimicry of eggs in parasites. Since both these adaptations are influenced by birds' visual system, in all my studies I used an objective method to measure the colour and the modelling of avian visual system that is quite different from the human visual system. For instance, humans in contrast to birds cannot perceive ultraviolet (UV) light. However, this part of spectrum influences behaviour of birds substantially (e.g. courtship or foraging). We found that the hosts of brood parasites can use UV light when recognizing parasitic eggs. However, it seems that this part of spectrum is not the main cue in egg recognition (manuscript 1). Ambient light has also an important impact on colour perception. We determined whether the light conditions in nests influence host responses to alien eggs. The Red Bishop (Euplectes orix) was an ideal...
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Phylogeny of selected species groups of the genus Torymus (Hymenoptera: Torymidae)
Křížková, Barbora
Chalcid wasps (Chalciodiodea) is superfamily within parasitic group of the order Hymenoptera. These insects attack other arthropods. My thesis is focused on phylogeny of selected species groups of the genus Torymus Dalman 1820, whose range of hosts includes mainly gall-forming insect as gall wasps (Hymenoptera: Cynipidae) and gall midges (Diptera: Cecidomyiidae). Using genes 28D2 rDNA, COI and CytB, I constructed phylogenetic trees, which helped with discussing current view on classification of the genus and with inferring new findings about co-evolution with host organisms. Previously established morphological - ecological species groups were not supported by my analyses in many cases. Morphological traits seem to be convergent for many species. They often do not support observed monophyla as apomorphies. On the other hand, ecology and natural habitat of species was common for many branches in my cladograms. It was found out, that recent hosts are not probably original hosts of the group. Adaptive radiation in different habitats is likely to be the phenomenon that stands behind present-day host range of Torymus species. This process could have occurred after swapping to gall midges and gall wasps. Key words: Chalcidoidea, Torymus, phylogeny, parasitoid, host specifity, co-evolution
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Experimental research of specificity of fear of snake: coral snake pattern
Průšová, Lucie ; Frynta, Daniel (advisor) ; Veselý, Petr (referee)
Due to shared coevolutionary history of snakes and primates with snakes acting as their main predators, snakes elicit fear in most of the primates, humans included. Humans are able to notice a stimulus that elicits fear, e.g., a snake, much faster. Such ability might have surely positively affected their survival in the past. In the nature, aposematic coloration acts as a warning of a dangerous prey to its predators not to devour it. The highly poisonous American coral snakes have this coloration pattern. The harmless king snakes of the Central and North Americas gain an anti-predatory advantage by becoming the coral snakes 'Batesian mimics, copying their bright pattern. Such pattern elicits an innate fear reaction in various species of wild birds who avoid a mere contact with patterned plastic dummies. The question arises whether other taxa, including primates and humans, generally recognize such pattern as dangerous. The aim of this study was to find whether humans fear coral snakes, although they have not long coevolutionary history with them. Further it was analyze, which visual factors of the snakes affect this fear reaction (i.e., a warning coloration, pattern or shape of snake). The atractiveness of these snakes was tested. Another question was whether humans are able to intuitively recognize...
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Animal phobia: fear or disgust?
Peléšková, Šárka ; Landová, Eva (advisor) ; Hocko Fajnerová, Iveta (referee)
Animal phobias are among the most common specific phobias. It is traditionally assumed that two basic emotions are involved - fear and anxiety, although recent studies suggest that disgust may also be important. Phobias and involved emotions are defined mostly by psychologists and psychiatrists. Their manifestations could be identified mainly on physiological level and are being researched using advanced medical methods (e.g. functional neuroimaging). The eliciting stimuli of arachnophobia, ophidiophobia etc. are specific animal, spiders or snakes. However the category of elicitors for disgust sensu lato is fairly extended. The etiology of these phenomena is explained from the perspective of evolutionary biology and presumes biologicaly significant selective pressures and common coevolution. The aim of this paper is to summarize information gathered so far, verify proposed evolutionary hypothesis about the involvement of disgust in the etiology of animal phobia and to evaluate biological relevancy of fear of animal stimuli.
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Phylogeny of selected species groups of the genus Torymus (Hymenoptera: Torymidae)
Křížková, Barbora ; Janšta, Petr (advisor) ; Skuhrovec, Jiří (referee)
Chalcid wasps (Chalciodiodea) is superfamily within parasitic group of the order Hymenoptera. These insects attack other arthropods. My thesis is focused on phylogeny of selected species groups of the genus Torymus Dalman 1820, whose range of hosts includes mainly gall-forming insect as gall wasps (Hymenoptera: Cynipidae) and gall midges (Diptera: Cecidomyiidae). Using genes 28D2 rDNA, COI and CytB, I constructed phylogenetic trees, which helped with discussing current view on classification of the genus and with inferring new findings about co-evolution with host organisms. Previously established morphological - ecological species groups were not supported by my analyses in many cases. Morphological traits seem to be convergent for many species. They often do not support observed monophyla as apomorphies. On the other hand, ecology and natural habitat of species was common for many branches in my cladograms. It was found out, that recent hosts are not probably original hosts of the group. Adaptive radiation in different habitats is likely to be the phenomenon that stands behind present-day host range of Torymus species. This process could have occurred after swapping to gall midges and gall wasps. Key words: Chalcidoidea, Torymus, phylogeny, parasitoid, host specifity, co-evolution
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Evolution of Morality, Morality of Evolution
Šafránek, Jakub ; Komárek, Stanislav (advisor) ; Stella, Marco (referee)
The goal of this work is to present attitudes of two contemporary authors who are in the center of the evolutionary-origin-of morality debate, that is theories of Richard Dawkins and Frans de Waal. The critical reflection of their works on this topic will center around the building blocks of morality and the supposed "moral sense", which according to the dutch primatologist humans to some extent share with some of their living evolutinary relatives. In case of Richard Dawkins we are about to review his meme theory and parasytical character of some elements of culture. Morevoer there will be presented accounts of the dual inheritance theorists, which in authors opinion can reunite both presented authors and thier attitudes, i.e. put the parasytic/independent character of memes in accordance with the building blocks of morality approach. This approach in turn can explain many phenomena of human contemporary morals and their limits. Keywords: Morality, evolution, dual inheritance theory, coevolution, memes
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Multilokusová charakteristika symbiontů entomopatogenních hlístovek rodu \kur{Steinernema}
FAKTOROVÁ, Lucie
During the evolution some groups of organisms have become coevolutionary associated with other groups, as is the case of host symbiont systems. To explore coevolutionary history of hosts and their associated symbionts, phylogenetic reconstruction of symbionts and phylogenetic reconstruction of hosts are usually compared. Coevolution is described by coevolutionary events (cospeciation, host switch, duplication, failure to diverge events and linage sorting events). The aim of this work was to test the suitability of MLST method for the complex of entomopathogenic nematodes from the genus Steinernema (with detailed analysis of Steinernema feltiae) and their symbiotic bacteria Xenorhabdus bovienii and subsequently use cophylogenetic comparative analysis to determine their level of cospeciation.
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Specificity of insect-plant associations and their role in the formation of plant defenses and speciation
VOLF, Martin
The aim of this dissertation is to investigate what role insect-plant interactions play in the formation of host-plant defenses and in the diversification of both groups. We show that various groups of herbivore respond differently to host-plant defenses. Therefore plant defenses diversify into suites of complementary traits, as individual traits fail to provide protection against specialized herbivores. Further, we identify what levels of host-phylogeny shape the food-web structure of insect herbivores. We show that specialized herbivores are affected mainly by the terminal parts of the host-phylogeny. In contrast, more polyphagous guilds are affected mainly by the mid-levels of the host phylogeny because the effects of terminal or deeper phylogeny seem to be surpassed by other factors in more generalist insect species. In the last chapter, we show how specialized insect-plant interactions generated by tight insect-plant coevolution can influence the speciation in plants over environmental gradients.
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