Thesis (PhD)--Stellenbosch University, 2013. / Pollinators play a fundamental role in floral evolution. They can exert selection on the flowers they visit in a plethora of different ways, ranging from innate floral preferences to differences in body size and shape and behavioural elements such as flower constancy and learning capacity. Since different pollinators exhibit differences in these characters, shifts between pollinating species are often considered the most likely drivers of floral diversification. While many lines of evidence support this claim, numerous angiosperms pollinated by a single species also exhibit floral variation. Throughout my thesis, I explore and investigate floral diversification in such species in the absence of pollinator shifts. In Chapter 2, I investigate variation in the preference of conspecific male and female pollinators for the floral traits of a sexually deceptive daisy that comprises distinct floral forms. I show that its pollinator exhibits gender-specific variation in floral preferences, and that some floral forms have specialized on the male pollinator. This chapter thus illustrates the importance of intraspecific variation in pollinator preference for floral diversification, an underappreciated mechanism in this field of research. The innate preferences of pollinators are likely to have a genetic basis, especially innate preferences that govern mate choice. Genetic structure within the pollinators of sexually deceptive plants, which mimic female insects to achieve pollination, may thus provide an important source of selection on the plants they pollinate. This depends on an association between genetic divergence and divergent mate preferences, and I explore this intriguing idea in Chapter 3. While pollinators associated with sexually deceptive floral forms did exhibit significant genetic structuring, male pollinators from different phylogeographic clades all exhibited preference for the same sexually deceptive floral form, thus rejecting this hypothesis. Another behavioural attribute of pollinators that may affect floral evolution, particularly in deceptive plant species, is learning ability. Studies on sexually deceptive orchids often report that male pollinators tend to avoid sexually deceptive flowers with experience. In Chapter 4, I systematically investigate learning abilities within male pollinators and the costs they suffer on sexually deceptive floral forms that vary in deceptiveness. Results reveal a positive relationship between the level of floral deceptiveness and the 4 associated mating costs that deceived males suffer. Pollinator learning, however, appears to occur only on the most deceptive floral forms, suggesting a link between the costs suffered to the occurrence of learning. In Chapter 4, I systematically investigate learning abilities within male pollinators and the costs they suffer on sexually deceptive floral forms that vary in deceptiveness. Results reveal a positive relationship between the level of floral deceptiveness and the associated mating costs that deceived males suffer. Pollinator learning, however, appears to occur only on the most deceptive floral forms, suggesting a link between the costs suffered to the occurrence of learning. In Chapter 5, I explore the importance of florivory damage in a polymorphic daisy. Studies on floral evolution often overlook the significance of florivorous visits and focus only on pollinator-mediated selection. I show that floral polymorphism is maintained by antagonistic selection exerted by pollinators and florivores on the same floral traits. Lastly, I focus on evolutionary history to explore similarity in the patterns of South African angiosperm evolution and the pollinator species used throughout my thesis. Molecular dating shows this pollinator exhibits broadly congruent evolutionary patterns to these angiosperms, indicative of a shared biogeography. Taken together, my thesis demonstrates the vast impact of floral visitors, in particular pollinating insects, on the evolution of floral form. / My research was funded by the National Research Foundation of South Africa (NRF) and personal funding was provided by a NRF Innovation scholarship and merit bursaries from the Botany and Zoology department at Stellenbosch University. A WhiteSci Travel Grant and financial support from Prof. Erik Svensson at Lund University also allowed me to present parts of my research at international conference.

Tyrime dalyvavo 283 tiriamieji (138 vaikinai ir 145 merginos). Tiriamąją imtį sudarė Kauno m. ir Kauno rajono vidurinių mokyklų 9 -11 klasių moksleiviai. Paauglių fizinio aktyvumo lygis buvo vertinamas naudojant „Modifikuotą tarptautinį fizinio aktyvumo klausimyną“ (IPAQ- International Physical Activity Questionnaire; Ainsworth, Levy, 2004; Volbekienė, 2006), emociniams bei elgesio ypatumams nustatyti naudotas „11-18 metų jaunuolio savęs vertinimo klausimynas“ (ASEBA – YSR 11/18, Achenbach System of Empirically Based Assesment - Youth Self Report; Achenbach, 2001; Žukauskienė, 2006). Sveikata vertinta darbo autoriaus sudarytu klausimynu. Tyrimo rezultatai parodė, kad paauglių fizinis aktyvumas susijęs su sveikata ir kai kuriais emociniais bei elgesio ypatumais: fiziškai aktyvesni paaugliai geriau vertino savo sveikatą, jų nerimo/ depresijos išreikštumas buvo žemesnis lyginant su fiziškai pasyvesnių paauglių grupe. Didėjant vaikinų fiziniam aktyvumui jų agresyvumas didėja. Fizinio aktyvumo lygis neturėjo ryšio su merginų agresyvumu, paauglių delinkventiniu elgesiu ir užsisklendimu. / The study was conducted among 283 teenagers (138 boys and 145 girls). The selection was made from the 9-11th form students in Kaunas City and District secondary schools. The level of physical activeness was measured according to The International Physical Activity Questionnaire (Ainsworth, Levy, 2004; trans by Volbekiene, 2006). Emotional and behavioural aspects were evaluated using The Questionnaire of Self Assessment for 11-18 year olds (ASEBA- YSR 11/18, Achenbach, 2001, trans by Zukauskiene, 2006). Health levels were assessed using a questionnaire constructed by the author of the study. The results of the study have indicated the link between teenagers’ physical activeness and their health, some emotional and behavioural aspects: more physically active teenagers evaluated their health better; their anxiety/depression indicators were lower compared to those of the less physically active. Whilst the aggression in boys grew respectively with rising physical activeness, such a link wasn’t found in girls. No connection between physical activeness and teenagers’ delinquent behaviour or shyness was determined.