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Lizard growth and the ontogeny of sexual size dimorphism
Meter, Brandon ; Starostová, Zuzana (advisor) ; Kupfer, Alexander (referee) ; Vrtílek, Milan (referee)
Růst byl u plazů historicky považovaný za neukončený. Tento obecně sdílený předpoklad byl v posledních letech zpochybněn a narůstaly důkazy o ukončeném růstu u ještěrů. Tento obrat způsobila především analýza růstových plotének kostí, která ukázala jejich uzavření a tím nemožnost dalšího prodlužování kostí, což způsobuje dosažení konečné velikosti těla. Paralelně s touto změnou v nahlížení na ukončený růst byly zpochybněny i dlouhodobé předpoklady o zásadní přímé roli energetického rozpočtu a s ním spojených trade-offs v ovlivňování růstu. Tento posun v perspektivě ovlivňuje nejen naše chápání individuálního růstu, ale také se odráží ve studiu souvisejícího znaku - pohlavního dimorfismu ve velikosti (SSD) - rozdílu ve velikosti mezi pohlavími v rámci druhu. Existují tři hlavní hypotézy o příčinách SSD u plazů: pohlavně-specifické náklady na reprodukci, ovlivnění růstu samčími gonadálními androgeny a ovariálními hormony. Tato práce přináší další důkazy o ukončeném růstu u ještěrů a diskutuje jeho důsledky pro evoluci SSD. Review o růstu zaměřené na gekona Paroedura picta, kde jsou větší samci než samice, zdůrazňuje značnou kanalizovanost růstu a současně poskytuje základ o úvahách týkajících se proximátních příčin SSD. V této práci dále předkládám podporu pro pravděpodobnou roli ovariálních hormonů...
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Olfactory adaptations in the deep-sea fishes
Kamrla, Jaroslav ; Musilová, Zuzana (advisor) ; Stopková, Romana (referee)
The goal of this work was to summarize the present knowledge about olfaction in deep-sea fishes. The research on this topic is seldom, however, few interesting studies suggest the importance of olfaction in these inhospitable conditions. After a short introduction of how the olfaction works, individual description of deep-sea adaptations follows. Implications on the importance of a specific sense can be made based on comparisons between individual brain areas responsible for the input of each sense. The importance of individual senses was investigated in mesopelagic and demersal species. Ontogenetic shift in sensory importance is one of the adaptations. Furthermore, sexual dimorphism in the olfactory system. Enlarged olfactory organs in males are most likely responsible for easier localisation of a female. Regarding the olfactory receptor repertoire, a whole genome of a hadal fish from the Mariana trench marked a massive loss of olfactory genes but highlighted their specificity. My own data included in this thesis estimate the number of the olfactory genes in deep-sea fishes for which we lack the high-quality genome. The estimates (albeit with large confidence intervals) suggest rather smaller numbers of genes in most of the species, while there are some species with putatively expanded gene...
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Reproductory behaviour of millipedes (Myriapoda: Diplopoda)
Habrová, Jitka ; Dolejš, Petr (advisor) ; Tuf, Ivan Hadrián (referee)
Reproduction is one of the most important parts of life of each animal. Courtship and copulation are very diverse in millipedes and differ among orders and species. Examining millipedes during their reproductive period enable us to investigate their mating behaviour. In addition, complex copulatory organs, namely those of males, are important for species delimitation and identification. I summarize basic taxonomy and morphology of millipedes that help to understand further knowledge from copulatory organ morphology to their function during copulation or courtship. I deal with copulatory organs of males (gonopods, telopods) and females (vulvae) as well as with secondary sexual characteristics (hook-like structures, adhesive pads, forceps-like mandibles, glands). I briefly mention the course of courtship (licking, "Schwänzeln", holding, stridulation, drumming, tactile and chemical communication) and copulation for each millipede order to point out the main behavioural differences. Species from the orders Julida, Spirostreptida and Polydesmida are the best explored, whereas in order Polyxenida, behaviour of only one species is described - Polyxenus lagurus.
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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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Sexual dimorphism and interpopulation variability of the skull in time-distanced populations
Šutoová, Denisa ; Bejdová, Šárka (advisor) ; Suchá, Barbora (referee)
This diploma thesis deals with sexual dimorphism and interpopulation variability of skull morphology between recent Egyptian population and a historical population, which is not geographically distanced but originates from the Old Kingdom period (Egypt, 2700-2180 BC). Estimating sex and population affinity is an important part of the process of building a biological profile of unknown human remains, and the skull is one of the best parts of the skeleton to estimate these attributes. Sex estimation is based on the existence of sexual dimorphism, which is very population specific, and sex determination is more reliable when population-specific methods are applied. Therefore, it is required to perform population affinity estimation before sex determination. A total of 143 adult specimens were included in the analysis. 47 three-dimensional exocranial meshes of skulls of individuals originating from the Old Kingdom period (31 males and 16 females) and 96 CT images of the heads from the recent Egyptian population in the age range of 18-86 years. (49 males and 47 females). The material was evaluated using the methods of geometric morphometry. In the analysis of the form, significant differences between the sexes were found. The most sexually dimorphic areas were the supraorbital arches, glabella, arcus...
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Genomic imprinting and evolution of sexually dimorphic traits
Farkačová, Klára ; Kratochvíl, Lukáš (advisor) ; Munclinger, Pavel (referee)
Genomic imprinting is a process whereby expression of an allele differs depending upon its parent of origin. It can be found on autosomes and also on sex chromosomes. Basic hypothesis for the evolution of genomic imprinting is the hypothesis based on the existence of sexual conflict. It can be classified into interlocus sexual conflict and intralocus sexual conflict hypotheses. Under interlocus sexual conflict hypothesis we can diffferentiate parental conflict hypothesis and parent-offspring conflict hypothesis. These theories were historically proposed for the first two taxonomical groups, where genomic imprinting was discovered, namely for angiosperms and placental mammals. Theory of parental conflict proposes that genomic imprinting evolved because the paternally inherited alleles are more selfish to mothers than are the maternally inherited alleles. Parent-offspring conflict hypothesis proposes that genomic imprinting evolved because maternal genes try to regulate demands of paternally inherited alleles in embryos. More recently, genomic imprinting has been found also in other taxons and in alleles, which do not bring any advantage during embryonic development. The intralocus sexual conflict hypothesis is applicable for every trait under sexually-specific selection. It provides potential...
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Shape, size and proportions of lower limb long bones among human populations from Eneolithic to the Modern Era.
Šídová, Markéta ; Velemínský, Petr (advisor) ; Brůžek, Jaroslav (referee)
Differences in the lifestyle of various populations may lead to changes in the shape of the long limb bones. This involves a reaction to the degree of mechanical and environmental stress acting upon these bones. Our work examined changes in the shape, proportions and size of the lower limb long bones (femur, tibia) over roughly the past five thousand years, or more precisely from the later phase of the Early Stone Age up to the 20th century. We studied the femurs and tibias of a total 520 adult individuals − 313 males and 207 females − from seven different periods or rather archaeological cultures. Our evaluation was based on the external, linear dimensions of the bones studied. Biological parameters were evaluated in relation to sexual dimorphism and lateral asymmetry. We paid special attention to the degree of flattening of the proximal third of the femoral and tibial shafts. Sexual dimorphism differed in individual populations. We found the least statistically significant parameters of sexual dimorphism in the oldest, Eneolithic, samples. In contrast, both sexes differed in the greatest number of parameters in the Early Middle Ages. Lateral asymmetry was most frequently demonstrated for the width dimensions in the case of the femoral and tibial diaphyses, which are in complete concurrence with...
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Ontogeny of exaggerated structures in dung beetles (Coleoptera: Scarabaeinae)
Žídek, Radim ; Šípek, Petr (advisor) ; Hanus, Robert (referee)
E n g l i s h a b s t r a c t Horns of scarab beetles represent a secondary sexual characters present mostly in males, to whom they serve as weapons in combats over the acces to females. In many species, two discrete male forms occur, "horned" and "hornless", which employ different reproductive strategies. Adult body size and horn morphology are determined by nutritional conditions encountered by larvae during their development. Switching between developmental pathways is accomplished by circulating levels of juvenile hormone (JH) which reflect body size, and genetically determined threshold of sensitivity to it. When body size is larger then threshold, horn growth occur, whereas if it's not, a brief pulse of ecdysone reprogramme the development and hornless adult emerge. Reprogramming the development encompass modifications of the insulin receptor pathway as well as changes in exact domains of genes expression envolved in specifying the proximodistal axis of the developing horn. Development of horns is morphologically reminiscent that of other insect appendages, with which it shares the expression of genes wingless, decapentaplegic, Distal-less, dachshund, homothorax, aristaless and EGFR, parts of gene regulatory network ensuring origin of the outgrowth of the cuticle. Some of them are expressed through...
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The variability of facial expressions in relation to age and sex: pilot study for monitoring the treatment of facial palsy.
Danková, Simona ; Velemínská, Jana (advisor) ; Schmidová, Kamila (referee)
This thesis deals with the analysis of 3D morphological changes and variability in the shape and form of facial expression during five specifically defined facial expressions (raising eyebrows, close both eyes, lips pursing, inflating both cheeks, smile). Changes in facial expression were evaluated in relation to sexual dimorphism and age category of probands using the methods of geometric morphometrics (Dense Correspondence Analysis, Paired Analysis, Principal Component Analysis, Shell-to-Shell Deviation) in program Morphome3cs and RapidForm. The analysis consisted of evaluating the surface of soft tissue changes that occur due to the contraction of facial muscles. Materials used for the analysis are 3D surface facial models of adult healthy people of the Czech nationality (63 women, 58 men) in the age interval 20-60 years. We considered methodology based on Paired Analysis to be more accurate, when we worked only with differences between the neutral expression and facial expression. By choosing a Paired Analysis, we prevented the morphological features of the face from being reflected into the results. Morphological features are a manifestation of sexual dimorphism or age factor as such, but they are not themselves the essence of facial expression. In this way, we analyzed the shape of the face after...
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Digital forensic anthropology and sexual dimorphism of recent population os coxae: implication for sex estimation.
Mesteková, Šárka ; Brůžek, Jaroslav (advisor) ; Dobisíková, Miluše (referee)
This thesis uses the metric evaluation of 3D models created from CT images. The study is based on an examination of 51 males and 55 females CT scans from recent European population and also based on a metric data (10 linear measurements) of the same geographical provenance of the mid-20th century (n=113). The purpose of our research project is to determine the degree of sexual dimorphism in current population and compare the degree of sexual dimorphism in this geographic area in the middle of the last century. Intraobserver variabilities of linear measurements were less than 2%. Both groups were statistically tested. An index of sexual dimorphism (ISD) was used to assess the level of sexual dimorphism within each sample (Paris ISD = 8,28, Marseille ISD = 6,50). The two-sided t-test indicates that the degree of sexual dimorphism is not significantly different between population from the mid-20th century and recent population (p = 0,680). The secular trend was expressed by the z-score. The results showed that changes in the pelvic bone between the two groups are not significant, since neither one of the measurements does not exceed ±2 SD. Finally, we verified the reliability of method DSP ("Diagnose Sexuelle Probabiliste") for measurements deducted from CT-derived models. The results showed the...
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