|
|
Comparative analysis of sexual and agonistic behaviour in eyelid geckos (Eublepharidae)
Rauner, Petr ; Kratochvíl, Lukáš (advisor) ; Frýdlová, Petra (referee)
Sexual selection is one of main selective pressure affecting body size, and subsequently leads to the evolution of sexual size dimorphism (SSD). The eyelid geckoes, family Eublepharidae, are a monophyletic group with considerable variability in SSD, including both male-larger and female-larger species. In general, it was supposed that eyelid geckos are highly variable in presence of male combats and in complexity of male pre-copulatory behaviour, and that this variability in this conspicuous male behaviour may lead to differences in SSD. The aim of this study was to reveal relationships between the direction of SSD and presence/absence of tail vibration during precopulatory phase and male combat behaviour. Using behavioural testing, it was revealed that male combats are present in all tested species, even in species, where the absence of such behaviour was supposed so far. In several species, the strong effect of seasonality to male aggression was observed, which may play a role in the evolution of SSD. The evolutionary changes in the presence/absence of tail vibration during precopulatory phase were independent on changes in the direction of SSD, the presence of tail vibration seems to be ancestral state for these lizards. During the evolution of this group, the tail vibrations disappeared four...
|
|
|
Evaluation of hybridization effect on fitness of eyelid geckos (Eublepharis, Gekkota) by performance tests
Kohoutová, Tereza ; Frýdlová, Petra (advisor) ; Sedláček, František (referee)
An interspecies hybridization is usually viewed from two sides - either as mistakes in a reproduction resulting in decrease of a hybrids fitness (e. g. loss or decrease of viability and fertility) or as a mechanism helping animals adaptively respond to environmental changes resulting in higher fitness. Fitness is usually represented as a set of correlates. One of the correlates is an organism performance which is represented by a set of maximal values from measured physical activities. This thesis focuses on the evaluation of the endurance and the bite force for gecko species E. macularius and E. angramayniu, their interspecies hybrids and intraspecies hybrids to determine their performance. The results show differences in the bite force among each of the tested groups. E. macularius has the lowest bite force, while the highest bite force was measured in E. angramayniu. The bite force of interspecies hybrids is intermediate in comparison to the parent species. Nevertheless, intraspecies hybrids of large form and white form of E. macularius exceeds their parents in measured bite force. The variability in bite force suggests a positive effect of hybridization on fitness. The bite force differences between the large form and the white form of E. macularius support the hypothesis that there exist more...
|
|
|
Comparative analysis of sexual and agonistic behaviour in eyelid geckos (Eublepharidae)
Rauner, Petr ; Kratochvíl, Lukáš (advisor) ; Frýdlová, Petra (referee)
Sexual selection is one of main selective pressure affecting body size, and subsequently leads to the evolution of sexual size dimorphism (SSD). The eyelid geckoes, family Eublepharidae, are a monophyletic group with considerable variability in SSD, including both male-larger and female-larger species. In general, it was supposed that eyelid geckos are highly variable in presence of male combats and in complexity of male pre-copulatory behaviour, and that this variability in this conspicuous male behaviour may lead to differences in SSD. The aim of this study was to reveal relationships between the direction of SSD and presence/absence of tail vibration during precopulatory phase and male combat behaviour. Using behavioural testing, it was revealed that male combats are present in all tested species, even in species, where the absence of such behaviour was supposed so far. In several species, the strong effect of seasonality to male aggression was observed, which may play a role in the evolution of SSD. The evolutionary changes in the presence/absence of tail vibration during precopulatory phase were independent on changes in the direction of SSD, the presence of tail vibration seems to be ancestral state for these lizards. During the evolution of this group, the tail vibrations disappeared four...
|
guest ::
