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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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Signaling function of plumage coloration in Yellowhammer males
Kauzál, Ondřej ; Petrusková, Tereza (advisor) ; Šálek, Miroslav (referee)
Sexual selection theory tries to explain evolution of apparently useless traits which mainly developed in males of numerous species. One such trait is also rich and vibrant coloration, typical for many of the bird species. These traits are difficult to be falsified, and therefore they honestly signal quality of the individual. Carotenoid coloration reflects the health condition and melanin coloration the social status, even though this traditional division might not be as strict according to the latest studies. Apart from these ways of maintaining honesty, recent studies are focusing more also on the effect of hormones, mainly two steroids: male sexual hormone - testosterone -, and the "stress" hormone - corticosterone. Both hormones could positively influence male's sexual traits such as ornamental coloration. On the other hand, elevated levels of these hormones possess risk to the organism (higher energetic expenditure, chronic stress), therefore also might potentially become costly. Using photographs of birds in standardized conditions as well as spectrophotometry I analyzed the plumage coloration of males of the Yellowhammer (Emberiza citrinella). Concentrations of testosterone and corticosterone deposited in feathers were analyzed using the LC-MS/MS. Also, for males in breeding season 2015,...
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Nest construction
Jenšovský, Václav ; Kreisinger, Jakub (advisor) ; Kratochvíl, Lukáš (referee)
The nest is in the life of birds important structure. It is a place where birds kept posterity throughout the period of reproduction. To make it nest offspring suitable place for development, must have a specific structure which is different for each type of variable. 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, and also the construction of the nest in intraspecific communication as a selectable character sexually. All these factors are aligning differently, 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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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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Boar vocalizations and their potential role in sexual selection
Roreitnerová, Daniela ; Linhart, Pavel (advisor) ; Schneiderová, Irena (referee)
The aim of this research was to gather existing knowledge about vocalizations of boars and their potential role in sexual selection. Few studies mainly from the 70s and 80s of the last century suggest that the so-called love song, emitted by males during courtship, could act as a stimulant that triggers mating. However, I did not find any evidence that boars significantly use calls in fights. Most studies deal with pig vocalization in a different context. For this reason, I tried to look at the studies of pig relatives - even-toed ungulates - to better evaluate the potential role of boar vocalizations in sexual selection. In their case, the influence of the calls on the sexual behavior of females and competing males was reported. It is possible to conclude that the role of boar vocalization is probably not that important as in red deers, for example, because boars use calls in short range communication. On the other hand, stimulatory effect on females was found in other species too. Further studies are needed to understand possible function of boar vocalizations that could be used for example in pig breeding to improve the effectiveness of artificial insemination of sows. Powered by TCPDF (www.tcpdf.org)
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Imprinting-like effects and homogamy as factor affecting the evolution of eye and hair colour
Joudal, Lukáš ; Kleisner, Karel (advisor) ; Bártová, Klára (referee)
Existing studies have demonstrated that choosing a partner is strongly determined by physical and personal characteristics of a parent of the opposite sex. This influence is affected by the quality of the relationship with the parent during one's childhood. There are many studies focused on choosing a partner in relation to self-similarity. They show that many characteristics are shared between partners. The partner self-similarity has a positive impact on one's satisfaction in and stability of a relationship. Previous research also shows consistency in choosing a partner, meaning there exists a resemblance among ex-partners. The main objective of this thesis is to make a contribution to understanding the mechanisms of choosing a partner based on similarity (colour of eyes and hair) with the parent of the opposite sex and/or based on self-similarity. Next aim is to explore consistency in choosing a partner according to phenotype characteristics (eye and hair colour). The online survey involved overall 1 266 participants, 942 women and 324 men. The survey provided following results. Women choose self-similar partners in terms of eye colour; they also choose their partners depending on the eye colour of their father. Those women with hair colour similar to their partner's show higher relationship...
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Secondary sexual traits and ageing
Novotná, Kateřina ; Tomášek, Oldřich (advisor) ; Svobodová, Jana (referee)
Sexual selection is a key evolutionary mechanism that is based on differential reproductive success among individuals. Sexual selection drives evolution of sexual dimorphism and secondary sexual traits. These traits are often of ornamental character and may function as indicators of individual quality and viability in mate-choice. Ornamental traits may signal viability in two ways: either directly, when their expression reflects body condition and ornament predicts the probability of future survival; or indirectly, if their expression is age-dependent and intense ornament express only individuals that proved the ability to survive to old age. Ornament expression may also decline in old age, however, as a result of negative effect of senescence. The aim of my thesis was to assess, whether, and which, ornaments signal individual age and survival in free-ranging vertebrates with determinate growth and whether is ornament expression affected by senescence.
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The role of minority type preference in human sexual selection
Pokorný, Šimon ; Kleisner, Karel (advisor) ; Třebický, Vít (referee)
Minority phenotype preference, or the negative frequency-dependent selection is a type of selection, where a feature is more preferred, the lower it's frequency is in the population. Even a weak effect in other-preference based sexual selection can result in a sustainable polymorphism. This study reviews the phenomenon in the context of human visual facial features. Common trends in attractiveness shape the morphology of the human face towards uniformity. Individual recognition however, as a condition for most social relations, uses the wast variability of different features. This variability could be formed and maintained by minority phenotype preference. In our study we tested the effect of minority phenotype preference in the selection for rare hair and eye colors. In 120 unique sets, each containing six photographs, we experimentally manipulated the frequency of each color type. These sets were then shown to 226 human raters. We tested whether the relative frequency of each color type affected the rating of individual stimuli. In hair color, significant effect of minority phenotype preference was detected when females rated the photographs of men. When males rated the photographs of females, the effect was significant in eye color only. Key words: face perception, sexual selection,...
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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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Sexually dimorphic signs of human face within the life history theory
Klusáčková, Tereza ; Flegr, Jaroslav (advisor) ; Třebický, Vít (referee)
Tereza Klusáčková: Sexually dimorphic signs of human face within the life history theory Charles University in Prague, Faculty of Natural Science, Department of Philosophy and History of Science Bachelor's thesis, pages 39, 2014 Sexually dimorphic signs play a role in a mate choice. To produce quality offsprings it is necessary to choose an individual with our preffered attractive signs which reveal good genetic material of their bearer as a partner. Presented research explains a concept of the life-history theory and also the sexual selection and its theories. A key part of it is focused on a brief anatomical description of superficial structures of human face with an emphasis on masculine and feminine appearance and dedicates to thein changes during an ontogeny. It generally defines an attractiveness, examine preferences of the opposite sex for masculine and feminine characteristics and describes changes of female appearance and preferences during the menstrual cycle. This thesis deals with topics of symmetry and averageness, which refer to good state of health and high-quality genetical basis of an individual. Marginally deals with heterozygosity and studies exploring the effect of MHC genes on the perception of attractiveness. Key words: human face, life history theory, sexual selection, sexual...
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