Dissertationen zum Thema „Mimikry“
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1
Fries, Torsten. „Synchronisation in der emotionalen Kommunikation Vergleich zwischen traumatisierten Patienten, Fibromyalgie-Patienten und Gesunden /“. [S.l. : s.n.], 2004. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11103973.
2
Keller-Kemmerer, Nina [Verfasser]. „Die Mimikry des Völkerrechts : Andrés Bellos "Principios de Derecho Internacional" / Nina Keller-Kemmerer“. Baden-Baden : Nomos Verlagsgesellschaft mbH & Co. KG, 2018. http://d-nb.info/1169988865/34.
3
Schmitz-Urban, Ingo Christian [Verfasser], und Katja [Gutachter] Biermann-Ruben. „Faziale Mimikry bei Depression - Eine EMG-Studie / Ingo Christian Schmitz-Urban ; Gutachter: Katja Biermann-Ruben“. Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2020. http://d-nb.info/122226160X/34.
4
Prokop, Andreas [Verfasser], und Sebastian [Akademischer Betreuer] Scheerer. „Gewalt und Mimikry : destruktive Aspekte der Selbstkontrolle bei amokartiger Gewalt / Andreas Prokop. Betreuer: Sebastian Scheerer“. Hamburg : Staats- und Universitätsbibliothek Hamburg, 2015. http://d-nb.info/1073970418/34.
5
Mauersberger, Heidi. „The Dynamics of Workplace Conflicts“. Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/22023.
Annotation:
Konflikte am Arbeitsplatz sind allgegenwärtig–sie erschweren den Berufsalltag und können schlimmstenfalls auch zu privaten Problemen führen. Dennoch ist unklar, wie genau Aufgabenkonflikte das Wohlbefinden und die Leistungsfähigkeit von Beschäftigten beeinflussen. Mechanismen, wann und warum Aufgabenkonflikte negative Folgen haben, wurde bisher wenig erforscht. Begründet werden kann dies damit, dass Aufgabenkonflikte bisher zumeist in Feldstudien mittels retrospektiven (und zudem subjektiven) Momentaufnahmen untersucht wurden. Das erste Ziel meines Vorhabens war es demnach, Aufgabenkonflikte in einer Tagebuchstudie sowie in einem kontrollierten Setting im Labor zu untersuchen, um deren emotionale und kognitive Konsequenzen präzise und unmittelbar zu erfassen.
Weiterhin haben bisherige Studien größtenteils situative Faktoren untersucht und persönliche Charakteristiken, die ebenfalls die Bewertung von Aufgabenkonflikten beeinflussen, außer Acht gelassen. Daher verfolgte ich als zweites Ziel eine ganzheitliche Sichtweise auf den Aufgabenkonflikt einzunehmen. Dafür explorierte ich, ob Unterschiede zwischen Personen emotionale Mimikry zu zeigen (d.h. die Emotionen anderer zu spiegeln) einen Einfluss auf die Beurteilung von Aufgabenkonflikten haben.
Um das Bild auf Aufgabenkonflikte zu komplementieren bestand mein finales Ziel darin, die Wirksamkeit einer Intervention zur Abschwächung von Konfliktkonsequenzen zu untersuchen. Hierfür wählte ich eine allgemein bekannte Strategie der kognitiven Umbewertung („Reappraisal") und prüfte, ob diese Strategie einen Aufgabenkonflikt als weniger emotional aufreibend und somit weniger destruktiv erscheinen lässt.
Durch die Integration von vier empirischen Studien, die in renommierten psychologischen Zeitschriften publiziert wurden, leistet meine Dissertationsschrift einen Beitrag dazu, die von Konflikten am Arbeitsplatz ausgehenden komplexen Wirkweisen besser zu verstehen, sowie Möglichkeiten aufzuzeigen Konfliktkonsequenzen zu modifizieren.Workplace conflicts have been widely recognized as a core social stressor across occupations with detrimental effects for employees’ task progress and employees’ general stress levels and health. Yet, the presumed destructive effects of task conflicts on employee outcomes, such as well-being and performance, have not been confirmed consistently. Further, the fine-grained mechanisms that explain the effects of task conflicts on employee outcomes have not been fully explored yet. This may be because most previous research relied on retrospective self-reports and the complex nature of task conflicts and their multiple emotional and cognitive consequences are difficult to disentangle in cross-sectional field studies. The first aim of my thesis was to examine the short-term effects of task conflicts by measuring conflicts using a diary approach with event-sampling methodology in the field (Study 1) and by inducing conflicts under controlled circumstances in the laboratory (Study 2). Further, previous studies mostly investigated the effects of the conflict situation on health and productivity outcomes. Hence, my second aim was to identify participant characteristics that influence the conflict evaluation in addition to the characteristics of the situation. In Study 3, we explored whether individual differences in emotional mimicry (i.e., the imitation of emotions of others) affect the evaluation of task conflicts. Finally, my last aim was to seek for strategies that help to buffer the negative effects of task conflicts. Hence, in Study 4, we investigated the effectiveness of a conflict re-evaluation (i.e., reappraisal) intervention on several (objective) indices of negative affect. Insights gained from these four studies give a more precise picture of the nature of workplace conflicts and of the modifiability of their consequences.
6
Kotulla, Katharina Lena [Verfasser], und Norbert [Akademischer Betreuer] Müller. „Das Tourette-Syndrom – ein Molekulares Mimikry? : eine prospektive Studie zur Untersuchung der Bedeutung des Proteins Ezrin als potentielles Autoantigen bei Streptokokken-induzierten Autoimmunerkrankungen in Bezug auf die Symptomatik, Pathophysiologie und Therapiemöglichkeiten des Tourette-Syndroms / Katharina Lena Kotulla ; Betreuer: Norbert Müller“. München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2021. http://d-nb.info/1240145349/34.
7
Kozák, Roman. „Detekce mimiky obličeje“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232099.
Annotation:
This master‘s thesis deals with the design and implementation of computer application for facial expression recognition. The first section describes the image processing, especially algorithms used in other parts of this thesis. The next section describes methods used for face detection, particularly the Viola-Jones detector. This is followed by a brief description of the basic facial expressions recognized by the application. The last two sections are dedicated to the design and implementation of the facial expression recognition algorithms and to the evaluation of the results.
8
Azmeh, Salma. „Mimicry and the hoverflies“. Thesis, University of Nottingham, 2000. http://eprints.nottingham.ac.uk/14070/.
Annotation:
Hoverflies (Diptera: Syrphidae) vary widely in their mimetic associations, comprising wasp-mimetic, bee-mimetic and non-mimetic species. Social wasp mimics are dominated by 'imperfect mimics' which outnumber their supposed models (Hymenoptera: Vespidae) by large factors. The purpose of this thesis is to determine to what degree Batesian mimicry can account for these paradoxes, and to test alternative hypotheses for the evolution of the yellow-and-black patterns. There is little evidence of an effect of wasp abundance on 'imperfect mimic' abundance across 23 years of trapping data, as predicted if mimics are protected from predators through their resemblance to wasps. The seasonal asynchrony and high abundance of 'imperfect mimics' relative to their models is also notable, as well as the possible significance of wasp predation on hoverflies. Predictions concerning the function of the colour patterns of 'imperfect mimics' are tested using the association between similarity to the model and flight agility (indirectly measured assuming a trade-off between reproductive potential and flight agility). There is no strong indication that mimetic protection is the primary function of the colour patterns, but the evidence concurs with an aposematic function, signalling to predators the unprofitability of attempting capture. These conclusions are tentatively supported by direct measures of flight agility, though the small differences among species are difficult to pick up. The data on reproductive morphology of hoverflies show considerable variation across species, especially in males. The existence of giant testes in some species suggests that methods of dealing with sperm competition in hoverflies are diverse and deserve further study. The high ratio of 'imperfect mimics' to both models and good wasp mimics is also partly explained by habitat disturbance; undisturbed habitats show significantly less 'imperfect mimics' as a proportion of the hoverfly population. Current relative abundance in the UK may therefore be very different to when the colour patterns evolved.
9
Groebe, Matthew Elliot. „Behavioral mimicry in the courtroom: Predicting jurors' verdict preference from nonconscious mimicry of attorneys“. Miami University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=miami1384364661.
10
Channa, Aravinda Wijesinghe W. M. „Photosynthetic antenna-reaction-center mimicry“. Diss., Wichita State University, 2012. http://hdl.handle.net/10057/5369.
Annotation:
The research presented in this dissertation discusses the mimicry of primary events in natural photosynthesis via artificial molecular constructs. Photosynthesis involves two major steps, absorption of light by antenna pigments and transfer of the excitation energy to the reaction center where charge separated entities are formed via photoinduced electron transfer (PET).
The synthesized artificial molecular systems are comprisedof porphyrin-fullerene, donor-acceptor entities due to their well studied photophysical properties which are essential to yield long-lived charge-separated states. Covalent and non covalent binding strategies have been employed in the design and synthesis of these novel artificial antenna-reaction centers.
The synthesized molecular systems are characterized using standard spectroscopic techniques. Their properties and performances in terms of an artificial photosynthetic model are evaluated by electrochemical, computational, time resolved emission, and transient absorption spectral studies. The systems studied reveal their potential in transferring excitation energy and yielding long-lived charge separated states with fast charge separation and slow charge recombination. The photoelectrochemistry of some of the compounds reveal their ability to convert light into electricity. Some triads show better performance as dyes in dye sensitized solar cells giving around 12% IPCE, incident photon-to-photocurrent conversion efficiency.Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry
11
Harper, George Raymond Pfennig David William. „Evolution of a snake mimicry complex“. Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,611.
Annotation:
Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biology." Discipline: Biology; Department/School: Biology.
12
Gloster, Tracey Maureen. „Transition state mimicry in glycoside hydrolysis“. Thesis, University of York, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533533.
13
Speed, Michael Patrick. „Mimicry and the psychology of predation“. Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278364.
14
Cowe, Glyn Andrew. „Example-based computer-generated facial mimicry“. Thesis, University College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406130.
15
Griffiths, David A. „Microbial mimicry of mammalian drug metabolism“. Thesis, Cranfield University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385132.
16
Trilla, Gros Irene. „Situated social cognition“. Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://edoc.hu-berlin.de/18452/24079.
Annotation:
In der vorliegenden Dissertation werden vier Studien vorgestellt, in denen untersucht wurde, wie altrozentrische (Mimikry) und egozentrische (Selbstprojektion) Prozesse der sozialen Kognition in Abhängigkeit vom sozialen Kontext und persönlichen Dispositionen reguliert werden.
Studie 1 zeigte, dass die Tendenz, fröhliche Gesichtsausdrücke anderer nachzuahmen abhängig von dem mit der beobachteten Person assoziierten Belohnungswert ist. Die Auswirkung der Belohnung ging jedoch weder in die vorhergesagte Richtung, noch konnten wir einen Einfluss von Oxytocin, einem Hormon, das der Neurobiologie der sozialen Anpassung zugrunde liegt, finden. Studie 2 zeigte, im Vergleich zu vorherigen Studien, keine allgemeine Verbesserung der automatischen Nachahmung nach direktem Blickkontakt im Vergleich zum abgewandten Blick. Wir konnten jedoch potenzielle dispositionelle Faktoren (z.B. autistische Eigenschaften) identifizieren, denen unterschiedlichen Mimikry-Reaktionen auf den Blickkontakt zugrunde liegen könnten.
Studie 3 kombinierte kurze Phasen der Emotionsinduktion mit psychophysischen Messungen der Emotionswahrnehmung. Es zeigte sich, dass emotionale Gesichtsausdrücke tendenziell als fröhlicher beurteilt werden, wenn Personen angeben, dass sie sich fröhlich im Vergleich zu traurig fühlen. Emotionale egozentrische Verzerrungen wurden in Studie 4 erneut untersucht. Im Gegensatz zu unseren Vorhersagen fanden wir jedoch keine stärkeren egozentrischen Verzerrungen, wenn die Teilnehmenden emotionale Gesichtsausdrücke von ähnlichen im Vergleich zu unähnlichen Personen beurteilten.
In allen Studien fanden wir Hinweise für den kontextabhängigen Charakter der sozialen Kognition. Allerdings konnten wir einige der in der Literatur berichteten Phänomene nicht replizieren. Diese Ergebnisse unterstreichen die Notwendigkeit, die Robustheit und Generalisierbarkeit früherer Befunde systematisch neu zu bewerten.This dissertation presents four studies that investigated how altercentric (mimicry) and egocentric (self-projection) processes of social cognition are regulated according to the social context and personal dispositions. Study 1 showed that the tendency to mimic others’ happy facial expressions depends on the reward value associated with the observed agent. However, the effects of reward were not in the hypothesised direction, nor could we detect an influence of oxytocin treatment, a hormone involved in the neurobiology of social adaptation. Study 2 could not detect a general enhancement of the tendency to automatically imitate others’ hand actions following direct gaze compared to averted gaze, in contrast to previous studies. However, we could identify dispositional factors (e.g., autistic traits) that might underlie different mimicry responses to gaze cues. Combining brief emotion induction blocks with psychophysical measures of emotion perception, Study 3 showed that facial emotional expressions tend to be judged as happier when individuals feel happy than when they feel sad. Emotional egocentric biases were replicated in Study 4. But contrary to our predictions, we did not find stronger egocentric biases when participants judged emotional facial expressions of similar compared to dissimilar others. Across all studies, we found evidence supporting the contextual nature of social cognition. However, we could not replicate some of the phenomena reported in the literature. These results highlight the need to systematically re-evaluate the robustness and generalizability of prior findings.
17
Emanuel, Lia. „Nonconscious behavioural mimicry : examining the methods used to produce mimicry and the automatic nature of the effect“. Thesis, University of Reading, 2012. http://opus.bath.ac.uk/30274/.
Annotation:
An individual’s tendency to adjust their behaviour, to unconsciously copy the gestures of another, is known as nonconscious behavioural mimicry. Chapter One reviews the facilitative role mimicry plays in social interactions and the underlying mechanisms of behaviour matching effects. However, the conditions under which mimicry occurs are not well characterised and, although accepted to be an automatic effect, this assumption remains empirically untested. This thesis examined the methods used to elicit mimicry and further explored the mechanisms underlying the effect. Chapter Two developed a paradigm to demonstrate mimicry relative to a suitable control condition and examined the generalisability of the effect to alternative gestures. However, mimicry was not observed. It was suggested that the target gestures were presented too overtly, and participant’s awareness was responsible for not demonstrating mimicry. Toward the refinement of the paradigm, Chapter Three focused on aspects of gesture presentation, namely, duration of exposure and gesture type. Although Experiment 2 found that mimicry was not influenced by the duration of exposure to target gestures, Experiment 3 showed that mimicry can generalise to alternative, localised, gestures. Crucially, both experiments demonstrated mimicry compared to an equivalent control condition. Chapters Four and Five examined the automaticity of mimicry, specifically the efficiency and awareness criteria. Experiments 4 and 5 did not allow for clear conclusions to be drawn about the efficiency of mimicry. However, the results from Experiment 6 provided clear evidence that lack of awareness is necessary for mimicry to occur and, when mimicry did occur, participants were unaware of their own mimicry behaviour. It was concluded that mimicry meets one of the hallmarks of automaticity; operating without awareness. The results of these experiments are discussed regarding the reliability of the mimicry effect and the methodological and theoretical implications of these findings for the mimicry literature.
18
Vorwerk, Michael Conrad. „A mathematical study of mimicry and opportunism“. Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/28944.
19
Wang, Yin. „The control of mimicry by social signals“. Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12401/.
Annotation:
One remarkable feature of social interactions is spontaneous mimicry. People have a tendency to unconsciously imitate other’s behaviours. This mimicry increases liking and affiliation between individuals and plays an important role in social cognition. Though mimicry is not normally consciously controlled, past research suggests that people mimic differently across social situations. In order to better understand the flexibility of mimicry in socal contexts, this thesis examined how social signals impact on mimicry by using a cognitive approach. Four behavioural studies consistently suggest that mimicry is subtly and strategically controlled by social signals. Specifically, in the first study we found that eye gaze is a powerful controlling signal on mimicry. Direct gaze rapidly and specifically enhances mimicry of intransitive hand movements. In the second study, we clarified that this eye contact effect on mimicry is not due to any arousal or attentional effect, but is driven by the social cue of direct gaze. In the third study, we found a joint effect of likeability and social status on mimicry. These two features interact in driving mimicry and optimize the affiliative function of mimicry in social interaction. Finally in the fourth study, we found that mimicry is sensitive to social primes. Prosocial and antisocial primes subtly modulate mimicry according to the self-relatedness of the primes. To further investigate the neural mechanism of the sutble control of mimicry by social signals, functional magnetic resonance imaging was used to examine the effect of eye contact on mimicry. The results showed that two key brain systems for social cognition—medial prefrontal cortex (mPFC) and mirror neuron system (MNS)—work together to control mimicry on line in social contexts. In particular, dynamic causal modelling analysis revealed that mPFC is the originator of the eye contact effect on mimicry and this region modulates the sensory inputs to the MNS according to gaze directions. These findings suggest that mPFC plays a key role in the strategic control of mimicry in social contexts. All experiments are then discussed in relation to current theories of mimicry. We suggest that this subtle and strategic control of mimicry is essential to human competence in social interactions and is important for our understanding of why and how people mimic.
20
Grewcock, David A. „The hoverflies : a case of "poor" mimicry?“ Thesis, University of Nottingham, 1992. http://eprints.nottingham.ac.uk/14073/.
Annotation:
The hoverflies (Diptera:Syrphidae) represent an apparently paradoxical visual Batesian mimicry complex, with what appear to be "poor" Mimics outnumbering their more accomplished counterparts. The purpose of this thesis is to determine how far conventional mimicry theory is capable of explaining the apparent paradoxes of mimicry in the hoverflies. It becomes obvious that determining the mimetic status of the supposedly poor Mimics is not a trivial task. Conventional experimental tests of mimicry, using captive predators, seem incapable of predicting the degree of protection enjoyed by a Mimic in the field. The research therefore concentrates on developing some novel empirical approaches to the study of mimicry. This includes developing a method of image analysis which yields an objective, single-value measure of the similarity between Model and Mimic patterns. This index of similarity is used to produce unique descriptions of the structure of mimetic communities in terms of Mimic frequency and similarity to the supposed Model. These profiles indicate that there is an objective basis to the perceived paradox, and suggest that there is not a simple relationship between the actual and perceived similarity of two patterns. The perceived similarity of Model and Mimic will be a key determinant of mimetic success. The index of similarity is also used as a basis for direct comparison of the supposedly mimetic hoverflies with a more established example of mimicry in the butterflies. This exercise demonstrates that an index of pattern similarity enables a unique comparative analysis of mimicry. It is proposed that an index of similarity also provides a unique opportunity to test our theoretical understanding of mimicry, if it is used in conjunction with a mathematical model that possesses some specific attributes. A suitable prototype model is developed and demonstrated. The thesis concludes with an indication that the novel empirical approaches developed here, have been adopted elsewhere. This latter work indicates that those hoverfly species which are apparently "poor" Mimics, may be exploiting some constraint in predator perceptual and cognitive systems to achieve mimetic protection, despite a relatively low degree of actual similarity to the Model species.
21
Eichbaum, Quentin Gavin. „Antigenic mimicry and autoantibodies in rheumatic fever“. Doctoral thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/26296.
22
Card, Ashley. „Locomotory mimicry in ant-like jumping spiders (Salticidae)“. Thesis, University of Canterbury. Biological Sciences, 2012. http://hdl.handle.net/10092/7680.
Annotation:
The jumping spider genus Myrmarachne (Salticidae) contains many different morphological ant mimics that resemble a wide variety of ant species. This mimicry enables Myrmarachne to evade ant-averse predators that confuse the spiders with ants. A conspicuous trait of Myrmarachne, which is frequently mentioned in the literature but has been overlooked experimentally, is locomotory mimicry. In this thesis, I quantified, for the first time, the locomotory pattern of non-ant-like salticids, Myrmarachne, and their presumed models. Indeed, I found that the locomotion of the mimics resembles that of ants, but not of other salticids. I then attempted to identify whether this behavioural mimicry enhances the morphological component of the mimicry signal. The locomotion component was tested by modelling a 3D computer animation based on the morphology of Myrmarachne, and then applying either non-ant-like salticid motion characteristics or ant-like locomotion to the models. These animations were presented to ant-eating salticid predators, which are known to have acute vision, in order to identify any differences in how the predators reacted to each virtual prey type based solely on differences in locomotory behaviour. No significant effect was identified for enhancing the deception, but there was a non-significant trend that hinted at an enhancement of the mimicry signal, suggesting that a more robust finding would be found with a larger sample size. Additionally, ant mimics are unusual in their relationship to their model organism, as the ant models are also potential predators of the mimic. Predation by visual ant species may exert selection pressure on Myrmarachne across some aspects of morphological or behavioural mimicry. In turn, this may select for traits that improve Myrmarachne’s survival in close proximity to their highly aggressive models. Consequently, I investigated whether ant-like locomotion is salient to a visual ant species, Oecophylla smaragdina. I found that the locomotion typical of ants and Myrmarachne is more attractive to ants than non-ant-like salticid locomotion. This suggests that the trade-off of increased resemblance to ants is not just towards being categorised as prey by ant-eating species, but also by being more attractive to ant species. This may place them at greater risk of predation by the model. As a whole, these results suggest that there is selection pressure on Myrmarachne for increased resemblance to a model by locomotory mimicry, despite associated costs when faced with ant-eating predators and when living in proximity to models that are both aggressive and visual.
23
Elliott, Christopher T. „Detection, pharmacokinetics and molecular mimicry of beta agonists“. Thesis, Queen's University Belfast, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247342.
24
Gramaglia, Irene. „MHC mimicry with autoantigens : possible role in autoimmunity“. Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244691.
25
Balogh, Alexandra. „Predator psychology and mimicry evolution : a theoretical analysis /“. Stockholm : Department of zoology, Stockholm university, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-29056.
Annotation:
Diss. (sammanfattning) Stockholm : Stockholms universitet, 2009.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Accepted. Härtill 4 uppsatser.
26
Kelley, Laura A. „Vocal mimicry in the spotted bowerbird Ptilonorhynchus maculatus“. Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/7569.
Annotation:
Vocal mimicry is well documented in songbirds, yet the function of this behaviour is poorly understood. I studied vocal mimicry in a wild population of male spotted bowerbirds Ptilonorhynchus maculatus to determine whether there was any support for the proposed functional hypotheses invoked to explain this behaviour. I collected observational data to determine what species male bowerbirds mimicked and how their mimetic repertoires related to the acoustic environment. Spotted bowerbirds preferentially mimicked the vocalisations of aggressive species, which is consistent with mimicry acting to deter predators or competitors (Batesian mimicry). However, these sounds were also relatively simple in terms of their structure, and may be mimicked purely due to their simplicity and similarity to the species-specific hiss. A survey of mimetic repertoires at three geographically isolated populations revealed a similar pattern in model choice: mimetic repertoires were predominantly composed of aggressive and predatory species but these sounds were also structurally simple. To test whether mimicry was used in a Batesian context I determined what contexts mimicry was produced in. Consistent with predictions, I found that males did not increase their mimetic rate in the presence of conspecifics but did increase their mimetic rate in response to human activity around the bower. To determine how mimetic sounds are acquired in this species, I compared the mimetic repertoires of individuals within a population and found that males with bowers closer together mimicked more of the same species than did males with bowers that were further apart. Closer inspection of two of these mimicked sounds revealed that neighbouring males did not produce structurally similar mimicry,which suggests that mimetic sounds are learned directly from the species being mimicked. Males did not increase their rate of species-specific vocalisation when mimetic rate increased, so these vocalisations are unlikely to serve the same function. Males increased their rate of species-specific hissing when in the presence of conspecifics and this vocalisation is likely to function in intraspecific communication. Males also produced ‘advertisement’ calls when alone at the bower that are likely to attract females to the bower or deter rival males. These vocalisations are a long distance signal that varied in structure in three populations of bowerbird. I discuss potential explanations for geographic variation in the structure of bowerbird vocalisations. Vocalisations may be part of the multi-component sexual signal produced by bowerbirds, but I found no relationship between any aspect of male vocalisation and predicted mating success, so these vocalisations are unlikely to indicate male quality to potential mates or rival males. In conclusion, it seems most likely that mimicry in this species is used to deter predators or competitors, but I cannot exclude the hypothesis that mimetic sounds are learned as a result of their relative simplicity and salience in the acoustic environment. Furthermore, I have shown that mimetic sounds in this species are most likely acquired directly from the species being mimicked. These findings are a useful step towards understanding the function and evolution of this fascinating behaviour.
27
Zhu, Qisheng. „Geo-mimicry for the Finger Lakes Tourist Center“. University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491316227158204.
28
Means, Jackson C. „Biodiversity, conservation and mimicry rings of Appalachian millipedes“. Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/99341.
Annotation:
The Appalachian Mountains contain some of the highest millipede diversity on the planet, including many endemic and range-restricted species. Millipedes have extremely low dispersal capacity, strict environmental requirements for survival and, in the case of the family Xystodesmidae, are completely blind. Coupled with the complex topology of the Appalachians, xystodesmid millipedes have speciated in the eastern United States to a greater degree than in any other region. Many of the taxonomic relationships within the Xystodesmidae remain to be tested using modern molecular techniques, and numerous species await description. The subtribe Nannariina, for example, contains 3 genera and 19 species, yet evidence suggests the tribe may actually contain over 100 species. Traditional taxonomic work has been hindered by a paucity of researchers in the field, and a necessary reliance on morphological characters for species delimitation. The external male genitalia, known as gonopods, are the structures which have most often been used to define species boundaries. However, in many groups, including the Xystodesmidae, the gonopods are extremely simple, making it difficult to discern whether similarity between gonopods is a result of shared ancestry or morphological convergence. Further complicating matters, somatic characters are often uniform between species, and some obvious phenotypes, such as color pattern and hue, are shared between genera in aposematic mimicry rings. Leading to the formation of mimicry rings between distantly related genera, their bright coloration functions to advertise a cyanide-based defense. Some species have been recorded as having six color patterns, each a member of a different mimicry rings. The factors which drive some taxa to participate in mimicry rings, while others have a myriad of hues and patterns, unmatched by other species, are unknown. Here I investigate the phylogenetic relationships between the tribes and genera of the Xystodesmidae, with the aims of (1) understanding the role of homoplasy within the Xystodesmidae, (2) delineating tribal and generic boundaries within the family, (3) describing species in the genus Nannaria for the purposes of revising the subtribe Nannariina, and (4) investigating mimicry and color variability through a detailed color atlas for North American Xystodesmidae. I found that 95% of the morphological characters traditionally used in xystodesmid taxonomy are homoplasious (HI > 0.5), delineated the Apheloriini, Appalachioria and Sigmoria, described 34 new Nannaria species, and created a color and mimicry dataset of 956 Xystodesmidae for use in future studies of color variability.PHD
29
Yates, Karen. „Teaching linguistic mimicry to improve second language pronunciation“. Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4164/.
Annotation:
This thesis tests the hypothesis that a whole language approach to ESL (English As A Second Language) pronunciation with emphasis on suprasegementals through the use of linguistic mimicry is more effective than a focus on segmentals in improving native speakers perceptions of accent and comprehensibility of ESL students' pronunciation of English. The thesis is organized into seven chapters. Chapter 2 is a discussion of the factors that affect the degree of foreign accent in second language acquisition. Chapter 3 gives a background on current ESL pedagogy followed by a description of the linguistic mimicry approach used in this research in Chapter 4. Chapter 5 and 6 are discussion of Materials and Methods and Conclusions and Implications.
30
Coe, Rebecca L. „Vocal mimicry in the spotted bowerbird (Chlamydera maculata)“. Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/13438.
Annotation:
Vocal mimicry - the copying of heterospecific sounds - is a widely spread but poorly understood phenomenon. The bowerbird family (Ptilonorhnychidae) are well known for their mimicry with most species incorporating mimicked calls into their elaborate sexual displays. Spotted bowerbirds (Chlamydera maculata), however, despite being competent imitators, do not include mimicry in their sexual displays. Here I discuss the vocal mimicry in this species, including suggestions of a possible function. I considered evidence for four hypotheses previously put forward to explain vocal mimicry. During observational studies I found that spotted bowerbirds preferentially mimic aggressive species and that the rate of mimicry also increases in the presence of such species. This suggests that mimicry may be involved in threat avoidance, as a type of Batesian mimicry. I tested this hypothesis using stuffed mounts of birds representing differing threats to the bowerbird. While there were some differences in species-specific vocalisation, such mounts did not appear to elicit a mimetic response. However, during experimental disturbances at the bower, some birds responded with an increased mimetic rate, supporting the threat avoidance hypothesis. It was evident that there was individual variation in both species-specific and mimetic vocalisation. I explored this variation in terms of duration of bower tenure and individual status. I also examined different ways to estimate the complete mimetic repertoire size. I considered different mechanisms for learning mimicry and showed that bowerbirds do not mimic the most commonly heard birds at their bowers, or the same calls as their relatives or nearest neighbours. Variation in bower design also occurs. In summary, given my data, the most likely function of vocal mimicry in the spotted bowerbird is threat avoidance.
31
Caswell, Clayton Christopher. „The SCL1 protein of Streptococcus pyogenes a structure-function analysis /“. Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=6026.
Annotation:
Thesis (Ph. D.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains xi, 190 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
32
Cameron, Dunlop D. „Antigenic mimicry as a strategy for aids vaccine design“. Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509923.
33
Jamie, Gabriel Adam. „Mimicry and speciation in the parasitic finches of Africa“. Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/268033.
Annotation:
In this thesis, I study a radiation of brood-parasitic finch species, the indigobirds and whydahs (genus Vidua), that occur across Africa. Host colonisation is tightly linked to speciation in Vidua because of their remarkable capacity to imprint on their hosts, with mating traits and host preferences being influenced by the parasite's early environment. The challenge of explaining why the radiation has diversified to the extent it has therefore simplifies to understanding why only certain potential host species have been successfully colonised. Following on from the introduction (Chapter 1), I begin by critically examining the logic with which mimicry in the natural world can be conceptually organized (Chapter 2). This creates a “mimicry landscape” in which to situate the mimetic adaptations of hosts exhibited by Vidua. The framework can be used to contrast and draw parallels between these and other mimetic adaptations present in the natural world. In Chapter 3, I review the literature on begging call mimicry and development across all avian brood parasite species. I outline the conditions under which we expect begging call mimicry to evolve, and when we expect it to develop primarily through genetic or environmental cues. This provides clear predictions for what we expect to occur in Vidua finches, which are tested in Chapters 4 and 5. In Chapter 4, I quantify the mimicry of host nestlings by Vidua in detail. I provide the first quantitative evidence that Vidua nestlings mimic the begging calls and show for the first time that Vidua are imperfect mimics of their hosts. In Chapter 5, I simulate the colonisation of a new host by transferring Vidua eggs into the nest of a new host species. I monitor Vidua survival in the foreign host environment and test several hypotheses about what explains differences in chick survival. I find that Vidua survive poorly in the new nest environment and that they do not show adaptive plasticity in begging calls or head movements. This poor survival occurs despite there being minimal differences in the diets each host species feeds their young. Finally, in Chapter 6, I carry out a comparative analysis on the evolution of estrildid mouth markings. Estrildid finches are the hosts of Vidua and so provide the landscape of potential ecological niches that Vidua may colonise and adapt to. I demonstrate that the host family shows strong phylogenetic signal in mouth marking traits, and find no evidence that ecological factors such as light environment or predation pressure has shaped estrildid mouth marking evolution. The work in this thesis highlights how difficult successfully colonising new hosts is for Vidua finches. Vidua must mimic hosts in multiple traits (mouth markings, begging calls, head movements) to obtain sufficient amounts of food from host parents. Overall, habitat filters, the complex and diverse begging displays of estrildid nestlings, the discriminatory behaviour of estrildid parents against mismatching chicks and the lack of adaptive plasticity in begging displays by Vidua together help explain why the Vidua radiation consists of only 19 species rather than many more or fewer.
34
Phillips, Neil. „Mimicry of cellular signalling pathways by enteropathogenic Escherichia coli“. Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613949.
35
Kitamura, Tasuku. „Behavioral mimicry of Batesian intraspecific polymorphism butterfly Papilio polytes“. 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120697.
36
Christensen, Peter Astrup [Verfasser]. „The Lewis Y antigen : Recognition and Mimicry / Peter Astrup Christensen“. Berlin : Freie Universität Berlin, 2005. http://d-nb.info/1021667846/34.
37
Cooper, Clare Mary Art College of Fine Arts UNSW. „The harp extended: an exploration of resonance, mimicry and improvisation“. Awarded by:University of New South Wales, 2008. http://handle.unsw.edu.au/1959.4/39899.
Annotation:
This research project explores methods of extension of the pedal Harp vocabulary in an attempt to develop a unique language that challenges the instrument's stereotype and better responds to a range of contexts. I have investigated three key areas of extension: the physical structure of the Harp and its internal resonant spaces, mimicry as an exploratory tool useful in better understanding the Harp in relation to the Australian environment, and improvisation both free and structured used to challenge the vocabulary of the Harp in solo performance and collaborative contexts. The research stems from my longstanding curiosity with regards to the limits that a sanctioned or stereotyped repertoire of sounds and techniques places on an instrument for those who engage both as players and listeners. This critical commentary documents the results of the three areas of exploration indicated above as well as exploratory practice undertaken by other Harpists, it also discusses the problematic term 'extended techniques??? and draws on interviews conducted with progressive Harpists and improvisers with regards to extending the vocabulary of their own instruments. The sixty concerts I have performed internationally over the research period have also been central to my research. The final work consists of three elements: a solo Improvised Harp performance in my family home in suburban Sydney (filmed and recorded), a recording of Second Stabbing (Ohnedaruth), a Harp-lead composition by my Berlin-based ensemble: Hammeriver, and a series of three short studies composed of recordings of the resonant spaces inside the Harp entitled Spinal Fluid. All four pieces draw from and address what I have learnt from exploring the resonant physical structure, mimicry and improvisation. The result is a unique language that challenges the stereotypical profile of the Harp as a decorative instrument by embracing both its unique resonance and capacity for darkness, subtlety and texture. This language allows for a more flexible response to a broader range of contexts.
38
Lakin, Jessica Lynn. „Exclusion and nonconscious behavioral mimicry the role of belongingness threat /“. Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1060011302.
Annotation:
Thesis (Ph. D.)--Ohio State University, 2003.Title from first page of PDF file. Document formatted into pages; contains xii, 111 p.; also includes graphics Includes bibliographical references (p. 100-109). Available online via OhioLINK's ETD Center
39
Thompson, Martin John. „The evolution of Batesian mimicry in the butterfly Papilio dardanus“. Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708557.
40
Hatten, Xavier de. „Toward hydrogenase mimicry : subjecting the problem to three different approaches“. Bordeaux 1, 2006. http://www.theses.fr/2006BOR13247.
Annotation:
Le travail présenté dans cette thèse est dédié à la création de modèles du site actif des enzymes hydrogénases. Cette problèmatique est soumise à trois approches différentes. La première stratégie utilisée est de type bioorganométallique. Un grand nombre de dérivés ferrocenoyl-peptide contenant des résidus soufrés (cystéine, méthionine) ont été synthétisés et caractérisés. Lors de la deuxième approche, concernant le domaine de la chimie organique, des hélices supramoléculaires à base d'oligoamides aromatiques ont été créées et isolées. Ces deux différents types de structures seront utilisés comme échelle moléculaire pour la création de modèle synthétique des enzymes hydrogénases. La troisième approche consiste en l'étude théorique des composés ferrocenoyl-peptides, en utilisant la dynamique moléculaire. Un champ de force a été implémenté dans CHARMM concernant ces composés et validé avec succès. Les calculs de mécanique moléculaire sont utilisés pour étudier les différentes structures pouvant servir d'échelle moléculaire. Après déprotection des groupements thiols sur les dérivés obtenus lors de l'approche bioorganométallique, les groupements SH sont coordonnés à un centre ferrocarbonylé, reproduisant le site actif de l'enzyme "Fe-only hydrogenase". Les complexes ainsi obtenus ont été caractérisés et leur propriétés électroniques et électrochimiques largement étudiées.
41
Lakin, Jessica L. „Exclusion and nonconscious behavioral mimicry: The role of belongingness threat“. The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1060011302.
42
Liu, Song. „The hepatitis C virus persistence: Immunoglobulin mimicry by E2 protein“. Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/27148.
Annotation:
The mechanisms by which hepatitis C virus (HCV) establishes persistent infection in the majority of infected individuals are unknown, but are thought to represent a complex interplay between viral diversity and host immunity. Currently, the most accepted hypothesis is that genetic variation within hypervariable region 1 (HVR1) of glycoprotein E2 may affect recognition by the immune system, leading to chronic infection. However, it can not explain how escape mutants evade subsequent immune recognition. Here, sequences within HCV E2 genes were analyzed during the course of primary HCV infections. We show that E2 possesses sequences that are homologous to sequences in the variable domains of human immunoglobulin (Ig) light chains in particular but also heavy chains and T cell receptors (TCR), and the degree of similarity of HVR1 to Ig types correlated with immune escape and persistence. In addition, recombinant E2 proteins (first 141 as or full length) were seen to bind to anti-human IgG antibodies, suggesting that N-terminal region of E2 is antigenically and structurally similar to human Ig variable domains. Overall, these data indicate that immunoglobulin mimicry by HCV E2 plays a significant role in viral immune escape and persistence.
43
Lindh, Anna. „Split Identities, Hybridity and mimicry within the characters in White Teeth“. Thesis, Halmstad University, School of Teacher Education (LUT), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-647.
Annotation:
The novel White teeth by Zadie Smith has been the object of my study in this essay. The aim of this study was to explore what the text communicated to the reader about hybridity and mimicry in the portrayal of some of the characters in the two families in White Teeth. The focus is on the male characters within the two families, as identity is created differently for men and women.
44
Cakirlar, Cuneyt. „Disidentification, mimicry, melancholia and image : queer reconfigurations in contemporary visual arts“. Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/17073/.
Annotation:
This thesis analyses expressions of queer tendencies in contemporary visual arts. Its main objective is to focus on gender-conscious strategies of performative excess realized by mimicries and triggered by identification and identity troubles. I use 'queer' to conceptualize a performance which perturbs hetero-normative dialectics of visual representation and disrupts the dynamics of its fixating recognition. I refer to the word 'tendency' in order to indicate the latency and/or the valency of the image in such a performance. Concentrating on the oeuvres of David Hockney, Robert Mapplethorpe, Del LaGrace Volcano, Cindy Sherman, Nan Goldin, Gilbert & George, Jake & Dinos Chapman, Todd Haynes and Derek Jarman, this thesis attempts to rethink ethics and aesthetics in the intersecting domains of queer theory, pastiche and contemporary artistic practice. My work focuses on the visual discourses of pastiche and parody in order to critically investigate the possibilities and the impasses of strategic mimicries, for instance the rhetoric of 'drag', with regard to representation. My case studies explore sexually informed methods of miming and pastiching and investigate the kind of dialogue that such narcissistic textual modes of queer self-consciousness might provoke. I read the art-works of these nine artists in terms of their possible affinities with queer problematizations of prevailing ideas about sexed, gendered, sexualized body. I treat these modes of mimicry, such as drag, copy, camp, pastiche and parody, within a logic of textual and sexual penetrations and consider them as queer practices of improper incorporations in the field of vision. My thesis further advances the argument that the queer performativities and thus the postmodern pastiche-effects in these visual modes encode a liminalized authorial signature, as well as authored modes of deviant temporalities. By means of detailed discussions of these nine key figures, I aim to demonstrate various author-functions in queer narrations of body and to consider ways in which they diversely utilize the aggressively melancholic and/or the radically narcissistic possibilities of the Queer in a critical aesthetic practice of surface and depth.
45
Butler, Patricia Helena Gerardine. „Molecular mimicry as a possible pathogenic mechanism in primary biliary cirrhosis“. Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309121.
46
Perera, Manuel. „Dengue virus exploits phosphatidylserine receptors ansd apoptotic mimicry for infectious entry“. Paris 7, 2014. http://www.theses.fr/2014PA077024.
Annotation:
La dengue est aujourd'hui un problème majeur de santé publique. L'agent étiologique de cette maladie est le virus de la dengue (DV), un pathogène émergent transmis à l'humain par des moustiques. Malgré d'intenses efforts, la caractérisation des interactions moléculaires qu'établit le DV avec la cellule cible lors des étapes initiales de l'infection, ainsi que l'identification des récepteurs permettant l'entrée virale demeurent à ce jour mal comprises. L'objectif général de mon travail de thèse a été de contribuer à comprendre la biologie cellulaire de l'entrée du DV et, plus précisément, à rechercher et caractériser de nouveaux récepteurs viraux. Dans ce but, nous avons réalisé un crible génétique à grande échelle permettant d'identifier des récepteurs cellulaires capables de promouvoir l'infection dans des cellules faiblement permissives au DV. Cette approche nous a permis d'identifier trois familles de molécules, TIM, TAM et CD300, comme potentiels récepteurs d'entrée du DV. Ces molécules ont la remarquable capacité d'interagir avec la phosphatidylsérine (PtdSer) à la surface des cellules apoptotiques. Nous avons démontré que ce phospholipide est incorporé dans les particules virales et qu'il est reconnu directement ou indirectement par les récepteurs TIM, TAM et CD300. Ce mode d'interaction potentialise fortement l'entrée infectieuse du DV et d'autres flavivirus dans divers modèles cellulaires selon un mécanisme qui mime la reconnaissance et l'élimination des cellules apoptotiques. Ces résultats indiquent que le DV utilise une stratégie de «mimétisme apoptotique » pour infecter des cellules et élargir son tropisme cellulaireDengue illness is a major health concern that threatens 2. 5 billion individuals worldwide. The etiologic agent of the disease is dengue virus (DV), an emerging pathogen that is transmitted to humans by mosquitoes. Vaccines and antiviral therapies against DV are lacking because some aspects of DV infectious cycle are still poorly understood. Indeed, despite intensive efforts, the characterization of the molecular interactions established between DV and target cells during the early steps of infection and the identification of the receptors involved in viral entry remain challenging. The main objective of my thesis was to gain further insight into the cellular biology of DV entry and, more specifically, to find and characterize new DV receptors. For this, we performed a high-throughput genetic screening to identify cellular receptors that promote DV infection in poorly permissive cells. This approach allowed us to identify three families of molecules, TIM, TAM and CD300, as potential entry receptors of DV. Lnterestingly, these molecules share the capacity to interact with phosphatidylserine (PtdSer) on the surface of apoptotic cells. We demonstrated that this phospholipid is associated with flavivirus virions and that it is directly or indirectly recognized by TIM, TAM and CD300 receptors. This mode of interaction promotes the infectious entry of DV and related flaviviruses in different cellular contexts by a mechanism that mimics the recognition and uptake of apoptotic cells. These results represent a major advance in the comprehension of DV entry programme and indicate that the virus exploits an "apoptotic mimicry" strategy to infect cells and enlarge its cellular tropism
47
Howarth, Brigitte. „An ecological study of Batesian mimicry in the British Syrphidae (Diptera)“. Thesis, University of Central Lancashire, 1998. http://clok.uclan.ac.uk/19285/.
Annotation:
This thesis is concerned with Batesian mimicry in British Syrphidae (Diptera), and examines the question of whether the ifies gain protection from mimicry. Batesian mimicry is the resemblance of a palatable animal (the mimic) to a distasteful or otherwise protected animal (the model), such that protection is gained by the mimic. Syrphidae (hoverflies) are colourfUl but defenceless insects which often resemble members of the Hymenoptera. This study provides evidence that certain species of hoverfly gain protection from their resemblance to Hymenoptera. In collaboration with Liverpool Museum the British Syrphidae were matched by eye to presumed model Hymenoptera. Once presumed model/mimic pairs had been suggested, a comprehensive survey of three sites in the north west of England was undertaken during 1994. Each site was visited once a week and counts were made of all Syrphidae and Hymenoptera on three plots at each site. Mean frequencies of models and mimics were compared, and it was found that mimics usually occurred when.models were present, and models were usually more abundant than the mimics; the data were also analysed usingan analysis of variance, and it was found that for most species tested there was a significant covariance between the mimic and presumed model numbers. Survey work in 1994 and 1995 showed that bumble bee mimics follow model rank order on each site, but not on all individual habitat plots. One aspect of fly behaviour of a bumble bee mimic was also studied (time spent feeding on flowers) and compared to other hoverifies and the presumed model. The results showed that the time the mimic spent on flowers was not the same as that of the presumed model. In the quest to understand hoverfly predation, immunological techniques are developed to test wild bird blood for evidence of antibodies against hymenopteran venom. The theory is that birds which have learned though a nasty experience that a particular colour pattern is distastefUl will also avoid other similar patterns, i.e. Wa bird is stung by a wasp it may not predate a hoverfly resembling the wasp. The main conclusion is that there are specific and non-specific mimics, and that nonspecific mimics significantly covary with model numbers, but specific mimics do not, which is not what one might have predicted if these hoverilies really do gain protection through Batesian mimicry. Also, it is possible to detect an immune response against wasp venom in birds and a method has been developed to embark on field trials in the future.
48
Kazemi, Baharan. „Evolution of Mimicry and Aposematism Explained: Salient Traits and Predator Psychology“. Doctoral thesis, Stockholms universitet, Zoologiska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-148488.
Annotation:
Aposematic species have evolved conspicuous warning signals, such as bright colors and striking patterns, to deter predators. Some edible and harmless species take advantage of this deterrent effect by mimicking their appearance. Mimicry is a great example of how natural selection produces remarkable adaptations. However, while some species evolve a very close similarity to their models to effectively avoid attacks, others are successful in doing so despite an incomplete similarity, i.e. imperfect mimicry. In some cases, it is surprising how such a crude disguise can fool predators. Why and how imperfect mimicry can persist has been much discussed and considered as a problem for the theory of natural selection. It is therefore of great interest to understand what makes it possible. Predator psychology is an important factor in the evolution of aposematism and mimicry. In the past decades it has been suggested that certain components of prey appearance are more important to predators than others during prey assessment. We developed this idea by incorporating concepts from associative learning, and presented a new approach to explain imperfect mimicry. Our general hypothesis is that prey traits have different salience to predators. Certain traits are perceived as highly salient and are thus used primarily in the discrimination and generalization of prey, while traits with low salience are overshadowed and not used in the assessment. The salience of a trait can depend on how conspicuous or discriminable it is in the particular context, and can vary due to for example previous predator experience. We tested our ideas with wild blue tits and domestic chickens as predators, and artificial and semi-natural prey stimuli. In paper I we found that the trait that was perceived as most salient (color) was the one used to discriminate and generalize between prey. Mimics of that specific trait were highly avoided, despite differences in the other traits. We also found that salience is relative and context dependent (paper II). In a context where two traits were perceived as similarly salient, mimicry of a single trait offered intermediate protection, while mimicry of both offered high protection. In another context, the traits were perceived differently salient, and mimicry of one trait was enough for high protection. In paper III we tested a proposed scenario for the initiation of mimicry evolution in the edible butterfly mimic Papilio polyxenes asterius to its noxious model Battus philenor. The results showed that a partial similarity with the model in the salient black wing color offered intermediate protection from attacks, despite a general dissimilarity. This thesis investigates the major questions of imperfect mimicry: the initial step of mimicry evolution, the persistence of imperfect mimicry, and variation in mimic-model similarity. We conclude that mimicry evolution can begin in a non-mimetic species that acquires similarity to a model species in a high-salience trait. When multiple traits have similar salience, multi-trait mimicry is needed for higher protection. Mimicry can remain imperfect if the differences are in traits with low salience, and therefore under low or no selection pressure to change. To complete the picture, we showed that predators can have a biased generalization toward a more pronounced version of a salient trait (paper IV). The evolution of aposematism could therefore be explained by gradual enhancement of salient traits.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Accepted. Paper 4: Manuscript.
49
Beccaloni, George William. „Studies on the ecology and evolution of Neotropical ithomiine butterflies (Nymphalidae: Ithomiinae)“. Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307456.
50
Kapan, Durrell D. „Divergent natural selection and Müllerian mimicry in polymorphic Heliconius cydno (Lepidoptera: Nymphalidae)“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ27174.pdf.