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Sexual dimorphism of the face and changes during senescence
Mydlová, Miriama ; Velemínská, Jana (advisor) ; Blažek, Vladimír (referee)
The human face shape is constantly changing during human life, even after one`s development stop (Hennessy a Moss, 2001; Williams a Slice, 2010). This work applies geometric morphometry method on study of sexual dimorphism of human face through ageing. Sexual dimorphism can be defined as a systematic difference in form between individuals of different sex of the same kind (Samal et al., 2007). Morphological changes, related to the process of ageing of human face, were analysed on data obtained from 3D surface models of human faces using methods of geometric morphometry (Dense Correspondence Analysis, Principal Component Analysis, Shell-to-Shell Deviation) and multivariatel statistics (Scree Plot, Hotelling`s Tš-test, permutational test, MANOVA). The work results indicates that the form (size with shape) and shape of men and women faces significantly change through ageing. Individuals aged between 20-40 years differ in form of the face, however the oldest men aged between 61-82 years differ from women only in shape of the face. The biggest differences in sexual dimorphism are in the middle age category (41-60 years), where there are significant differences not only in form, but also considering shape alone. Key words: ageing, form and shape, geometric morphometry, human face, sexual dimorphism 7
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Ontogenetic development of sexual dimorphism of the human face
Dadáková, Martina ; Velemínská, Jana (advisor) ; Cagáňová, Veronika (referee)
Sexual dimorphism is one of the basic features of the human facial variability. It is especially important when recognizing an individual, also in plastic and reconstructive surgery. It is one of the most significant paleodemographic aspects and it affects for example mate choice too. Sexual dimorphism arises very early during the ontogeny; it is already present in prenatal development. After birth it increases and develops due to contribution of various factors. Dimorphism is established mostly over the periods of childhood and adolescence, but it is possible to observe at least minor changes in the course of the whole life of an individual. Although different parts and structures of the craniofacial complex interact during their growth, they are to some degree independent from each other. That is why the sexual dimorphism can develop in them with different timing. This thesis summarizes the basic aspects of sexual dimorphism of human face during ontogeny together with the factors which are believed to cause this dimorphism.
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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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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 ; Hanus, Robert (referee) ; Šípek, Petr (advisor)
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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A comparison of selected ethological aspects of chosen tortoise species
BLAŽEK, David
In this thesis we studied individuals of 4 species of tortoises, often bred in captivity genus Testudo species T. hermanni, T. graeca, T. horsfieldi and T. marginata, in possession of the ZOO Hluboká nad Vltavou. We studied and analyzed their morphological parameters, size measurements, their weight and biometrical indexes, wheather they follow described sexual dimorphism as it was found out in non-captive populations. We also studied and analyzed their food preferences to find out differences between sexes and between keeping individual animal versus a group, by giving them a choice between 4 types of food (the red cabbage, leaves of dandelion and clover, and carrot roots). Sexual dimorphism displayed by different body proportions was most apparent in Testudo hermanni. In specimen from the ZOO of Testudo horsfieldi a T. graeca was sexual dimorphism less prominent. Measured Testudo females from the ZOO were in lowest, approximate and highest values bigger and heavier than males of the same species, which mirrors data from other studies of non-captive populations. Males are quicker to get to and quicker to start eating food than females. Males preffered red cabbage and carrot while the females clover and dandelion. The amplitude of preference change between individual and group experiment was not correlated by individual´s sex, species or size. We found out no apparent hierarchical enforcement from the side of faster or bigger specimen in the feeding process.
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Sexual size dimorphism of Salamandridae and its correlates with life history factors
ŠIMROVÁ, Lenka
Amphibians are important and interesting group of animals. Salamandridae are wellknown group of caudate amphibians. In this group we find sexual size dimorphism in three forms: bigger female than male, bigger male than female, and no difference in size. This fact was the impetus for my bachelor thesis, which deals with sexual size dimorphism for this family. The aim of this work was to determine to what forms of sexual dimorphism of size are different types and how it can be related to other selected factors. For this group of amphibians is true that more than half of the individuals are bigger female than male, a quarter of individuals is no sexual size dimorphism and the rest no individuals are bigger male than female. Statistical analysis showed a significant relationship between sexual size dimorphism and sexual courtship and amplexus.
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Mating systems and ecological correlates in family Rallidae
VRÁNA, Jakub
Correlation among ecological factors and mating systems of Rallidae was analysed. Tested factors included: sociality, fligthless, sexual dimorphism in colouration, sexual dimorphism in weight, occurrence in aquatic and semiaquatic biotopes and occurrence in terrestrial biotopes. Data was obtained from articles and books.
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Cognitive predispositions affected by degree of brain masculinity and femininity
PIXA, David
This thesis is concerned with gender-related differences of cognitive predispositions. Findings could be utilized predominantly in human resource management, pedagogy and psychology. The research was proceeded as a case study of 45 undergraduate students. Individual degree of masculinity/femininity (gender) was indicated by the Minnesota Multiphasic Personality Inventory (MMPI), while cognitive preferences were measured and described by Hermann Brain Dominance Instrument (HBDI). Another data were obtained by means of qualitative research methods, such as participant observation and semi-structured interviews. Besides, in general features were surveyed hand-lateral-preference, professional orientation and attention capability. All probands were divided into 6 categories according to gender and degree of MF. Synthesis of MMPI and HBDI results showed significant congruence between the gender-categories and a dominant preference of the HBDI{\crq}s cognitive styles: Masculine men {--} a dominant preference of A-mode (analytical thinking). Feminine men {--} a dominant preference of D-mode (imaginative thinking). Masculine women {--} a dominant preference of B-mode (sequential thinking). Feminine women {--} a dominant preference of C-mode (interpersonal thinking). This findings were in accordance with a professional orientation of the probands (regardless of the field of study they have choosen). Right-brain dominant students (mostly feminine men) were not well-adjusted to a classical passive teaching metods.
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