National Repository of Grey Literature 33 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Sustaining of RHD polymorphism in human population by selectin in favour of heterozygotes
Pokorný, Daniel ; Flegr, Jaroslav (advisor) ; Kaňková, Šárka (referee)
RhD polymorphism is an evolutionary enigma since the very discovery. Theoretically, the RhD- allele carriers should be eliminated through the negative selection against RhD positive children born to RhD negative mothers. The aim of this diploma thesis was to find out whether RhD positive heterozygous genotype is associated with the reduction of latent toxoplasmosis negative effects or even associated with improved psychomotor performances, memory or higher self-confidence, intuition and cognitive performances scores. Second of all, the aim of this thesis was to find out if RhD negative homozygotes exhibit worsened performances in the abovementioned characteristics and, consequently, see whether RhD polymorphism origin and maintenance could be achieved through the heterozygote advantage. General linear models that included listed variables, RhD genotypes and phenotypes, information about toxoplasma-infection status and age as a covariate were performed. Heterozygote Advantage hypothesis was supported in operational memory models and in case of women also in psychomotor performances models. On the other hand, models of short-term memory, self-confidence, intuition and cognitive performances scores did not support the formulated hypothesis. Keywords RhD polymorphism, selection favouring heterozygotes,...
Relationships among characteristics perceived from photos of faces
Machová, Kamila ; Flegr, Jaroslav (advisor) ; Děchtěrenko, Filip (referee)
Estimating others characteristics from facial cues plays an important role in our everyday lives. People usually agree in these estimates well and many of these estimates correlate. Majority studies consider one or few character- istics only and their respondents usually are in narrow ranges of ages. This study is partly based on rating of 13 characteristics of 80 men's and women's faces by respondents of various ages. These data were originally collected within yet unpublished study of Jaroslav Flegr, Amy E. Blum and Šebastian Kroupa. In this study I most strikingly found out that: i) older respondents of both genders rates photos of women as more attractive, ii) respondents spend more time by rating faces considered by themselves as more attractive or nice, iii) men rate people with different eye color as more attractive and women rate others with the same eye color as nicer, iv) preferences computed by two methods do not differ much. 1
Gender differences in behavioral changes induced by latent toxoplasmosis
Lindová, Jitka ; Flegr, Jaroslav (advisor) ; Špinka, Marek (referee) ; Ditrich, Oleg (referee)
Summaryof resultsofpresentedresearch Toxoplasmagondiiis a protozoanparasiteinfectingabout30%ofour population.After a shortphaseof acuteinfection,the parasitosistums into the lifelong latents.tagewhich is usuallyconsideredasymptomatic.However,in thestudiesperformedby our researchteam, latenttoxoplasmosiswasťoundto havespecificeffectson personality,behavior,morphology andphysiotogy.Interestingly'in manyaspects,theseeffectswereclearlygender-dífferent. My thesis was motivatedby results of previous questionnairestudies which found toxoplasmosisto haveoppositeinfluenceon men's and women'spersonalitytraitswarmth, conscíentiousnessandvigilancemeasuredby Cattell's16PersonalityFactorQuestionnaire (Flegretď. L996,1999,2000'FlegrandHavlíček1999'FlegrandHrdý 1994).Bothinfected womenand men werealso foundto score lower in novelryseeking(Skallová et al. 2005' Flegretal.2003). The resultof lowernoveltyseekingwas confirmedby thefirst studyperformedwith my contribution(lt{ovotnáet al. 2005).Moreover,this studyshowedthat regardingnovelty seeking,similar changeswere observedin subjectsinťectedby cytomega|ovirus.This was interprétedasevidenceforthehypothesisthatbehavioral/personalityshifu inducedby latent toxoplasmosiscouldbenonspecificchanges,causedby mildchronicbraininfections.Lower novelty seeking is thought to be associated...
Simulation of processes predicted by theory of frozen plasticity
Nekola, Ondřej ; Flegr, Jaroslav (advisor) ; Ponížil, Petr (referee)
The question of the tempo of evolution is amongst the oldest conundrums in evolutionary biology and has not been satisfactorily answered yet. One of the attempts to do so is the frozen plasticity theory, which postulates that a sexually reproducing species is only capable of evolution within short periods of time after its genetic polymorphism decreases e.g. as a consequence of peripatric speciation. In the longer periods of evolutionary stasis, its evolution is limited by frequency- dependent selection and pleiotropy. In this work, I have produced an open source software simulating the respon- ses of populations of sexually reproducing individuals to varying environmental conditions. Using this software, I simulated evolution of populations with different probabilities of arising of alelles affecting more phenotypic traits and frequency- dependent selected alleles that have opposing phenotypic effects when present at the locus in one copy, respectively two copies. I observed trends predicted by the theory of frozen plasticity: slower adap- tation to instant environmental changes, lower achieved fitness and more frequent extinctions of populations with higher portions of investigated types of alleles, but only with low effect sizes and without statistical significance. For future research, it would be desirable...
Relation between vocal expression and music and sexual selection in humans
Bauerová, Zuzana ; Flegr, Jaroslav (advisor) ; Šebesta, Pavel (referee)
This thesis deals with the role of acoustic cues and signals in human mate choice. It starts with a brief summary of mechanisms of sexual selection and acoustic communication in primates. The next part is focused mainly on human voice and its attractiveness. Finally, the possible role of singing and music in human sexual selection is discussed and evidence for the sexual selection hypothesis of music is gathered. Key words Vocal attractiveness, voice, human mate choice, evolution of music, sexual selection
The relation between hair characteristics and personality in humans
Sýkorová, Kateřina ; Flegr, Jaroslav (advisor) ; Kleisner, Karel (referee)
Numerous studies have described that physical traits correlate with psychological personal characteristics. However, associations between congenital hair characteristics and personality have not been studied yet. Such studies have focused only on the association of hair color with a few specific psychological characteristics or emotions. The aim of this study was to reveal whether people with different hair darkness, redheadedness or curliness vary in personality and sexual traits. We have found significant connection of these traits with hair darkness and especially with redheadedness and curliness for men and women. These hair characteristics were associated with self-rated personality characteristics, Big Five personality traits and sexual orientation and preferences. We have excluded the mediating role of some physical and psychological factors for many associations. However, in many cases the connections disappeared when controlling for these factors, thus there is a possibility of a mediating role of these factors in observed associations. The hypothesis concerning the effect of stereotypes based on different types of hair and self-fulfilling prophecy was also considered.
Factors influencing altruism
Kopecký, Robin ; Flegr, Jaroslav (advisor) ; Houdek, Petr (referee)
There are multiple theories about how moral judgement is made. In this study, we are investigating relationship between latent factors (moral conservatism, intelligence and CRT) and utilitarian versus deontological decisions in hypothetical moral dilemmas as variant of trolley problem. According to previous research moral judgement is made by proximate causes like Green's Dual process or Social-intuitionist model of Haidt. On the assumption of Partner choice (individual selection) we are able to test its predictions on moral dilemmas. The aim of this study was to investigate a possible link of these factors, proximal and ultimate mechanisms. Our results suggest that women display more harm aversion in moral dilemmas. Second, that there is a relation between sacrificial judgments in the hypothetical dilemmas and preference for sexual bondage. Third, that prediction of morality based on Partner choice model of evolution does not correspond to actual moral judgements. Key words: Altruism; moral judgement; thought experiments; Partner choice

National Repository of Grey Literature : 33 records found   1 - 10nextend  jump to record:
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3 FLEGR, Jan
3 Flegr, Jan
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