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Dryas iulia alcionea é uma espécie de borboleta que apresenta dimorfismo sexual em relação à coloração e ao tamanho das asas. Estudos em populações naturais mostraram que a variação no tamanho das asas dos machos é inferior a das fêmeas, sugerindo a ação de forças seletivas sobre a variabilidade das asas dos machos. Nesta tese, são apresentadas e discutidas evidências comportamentais, de desenvolvimento, genéticas e populacionais que podem explicar parcialmente os padrões morfológicos observados. Os principais resultados da tese são: (1) a forma das asas dos machos parece ser adaptada para vôos de longa duração, com alta eficiência energética, enquanto a forma das asas das fêmeas seria adaptada para vôos curtos, com alta manobrabilidade; (2) o repertório comportamental dos machos é maior do que o das fêmeas e diretamente relacionado à tentativa de efetuar cópula; (3) os machos buscam e cortejam ativamente as fêmeas (estratégia de patrulhamento); (4) as fêmeas parecem ter um papel decisivo no sucesso copulatório dos machos, já que a intensidade do cortejo dos machos parece não influenciar o sucesso copulatório; (5) os machos com padrões comportamentais menos variáveis parecem ter maior sucesso copulatório; (6) machos grandes e pequenos se comportam da mesma maneira frente a fêmeas receptivas, sugerindo que não existam estratégias alternativas para compensar efeitos causados por tamanhos corporais diminutos; (7) o tamanho dos machos não parece influenciar a escolha das fêmeas; (8) não há disputa direta entre machos (comportamento agonístico); (9) o tamanho das asas é uma característica com um moderado fator genético; (10) a correlação genética entre as características das asas dos machos e fêmeas é imperfeita, o que permitiria ou indicaria a ação de seleção sobre o dimorfismo sexual de tamanho das asas; (11) a correlação entre características das asas anteriores e posteriores é baixa, sugerindo uma considerável independência genética entre as características dos dois conjuntos de asas; (12) o tamanho apresenta significativa variação entre populações e estações do ano, sendo fortemente influenciado pelos recursos alimentares e temperatura durante o desenvolvimento larval. Com essas evidências, o modelo do equilíbrio diferencial de evolução poderia ser utilizado para explicar o dimorfismo sexual de tamanho observado, já que afeta as histórias de vidas, ecologia e comportamento. Assim, o dimorfismo sexual em D. i alcionea seria um epifenômeno resultante de forças seletivas atuado diferentemente sobre machos e fêmeas. / Dryas iulia alcionea is a butterfly species that shows sexual dimorphism in relation to wing color and size. Studies of natural populations showed that the variation in wing size in males is lower than in females, suggesting the action of selective forces on wing size variation in males. In this thesis, I present and discuss behavioral, developmental, genetic and populational evidences that could explain the morphological patterns observed. The main results of the thesis are: (1) wing shape in males seems to be adapted for long lasting flights, with high energetic efficiency, while wing shape of females seems to be adapted for short flights, with improved maneuverability; (2) males have a more numerous mating behavior repertoire than females, which seems to be directly related to attempts of genital coupling; (3) males court and actively seek for mates (patrooling strategy); (4) females seem to have a decisive role in the copulatory success of males, since the intensity of male courtship does not seem to influence male copulatory success; (5) males with less variable behavioral patterns during courtship seem to have greater copulatory success; (6) large and small males court receptive females in the same way, suggesting that they do not use alternative strategies to compensate for effects caused by small body sizes; (7) the male size does not seem to influence female choice during courtship, (8) there is no direct competition between males, with agonistic behavior; (9) wing size has a moderate genetic basis; (10) genetic correlation between males and females, for some wing traits, seems to be imperfect, which could indicate or allow the action of sexual selection on wing size and shape; (11) the genetic correlation between forewings and hindwings is low, suggesting some genetic independence between the two sets of wings; (12) wing size has significant variation among populations and seasons and is strongly influenced by diet and temperature during development. Considering these evidences, the differential equilibrium model of evolution could be used to explain the sexual size dimorphism observed, since it affects life histories, ecology and behavior. Thus, the sexual size dimorphism in Dryas iulia alcionea could be an epiphenomenon resulting from selective forces acting differently on males and females.

Dryas iulia alcionea é uma espécie de borboleta que apresenta dimorfismo sexual em relação à coloração e ao tamanho das asas. Estudos em populações naturais mostraram que a variação no tamanho das asas dos machos é inferior a das fêmeas, sugerindo a ação de forças seletivas sobre a variabilidade das asas dos machos. Nesta tese, são apresentadas e discutidas evidências comportamentais, de desenvolvimento, genéticas e populacionais que podem explicar parcialmente os padrões morfológicos observados. Os principais resultados da tese são: (1) a forma das asas dos machos parece ser adaptada para vôos de longa duração, com alta eficiência energética, enquanto a forma das asas das fêmeas seria adaptada para vôos curtos, com alta manobrabilidade; (2) o repertório comportamental dos machos é maior do que o das fêmeas e diretamente relacionado à tentativa de efetuar cópula; (3) os machos buscam e cortejam ativamente as fêmeas (estratégia de patrulhamento); (4) as fêmeas parecem ter um papel decisivo no sucesso copulatório dos machos, já que a intensidade do cortejo dos machos parece não influenciar o sucesso copulatório; (5) os machos com padrões comportamentais menos variáveis parecem ter maior sucesso copulatório; (6) machos grandes e pequenos se comportam da mesma maneira frente a fêmeas receptivas, sugerindo que não existam estratégias alternativas para compensar efeitos causados por tamanhos corporais diminutos; (7) o tamanho dos machos não parece influenciar a escolha das fêmeas; (8) não há disputa direta entre machos (comportamento agonístico); (9) o tamanho das asas é uma característica com um moderado fator genético; (10) a correlação genética entre as características das asas dos machos e fêmeas é imperfeita, o que permitiria ou indicaria a ação de seleção sobre o dimorfismo sexual de tamanho das asas; (11) a correlação entre características das asas anteriores e posteriores é baixa, sugerindo uma considerável independência genética entre as características dos dois conjuntos de asas; (12) o tamanho apresenta significativa variação entre populações e estações do ano, sendo fortemente influenciado pelos recursos alimentares e temperatura durante o desenvolvimento larval. Com essas evidências, o modelo do equilíbrio diferencial de evolução poderia ser utilizado para explicar o dimorfismo sexual de tamanho observado, já que afeta as histórias de vidas, ecologia e comportamento. Assim, o dimorfismo sexual em D. i alcionea seria um epifenômeno resultante de forças seletivas atuado diferentemente sobre machos e fêmeas. / Dryas iulia alcionea is a butterfly species that shows sexual dimorphism in relation to wing color and size. Studies of natural populations showed that the variation in wing size in males is lower than in females, suggesting the action of selective forces on wing size variation in males. In this thesis, I present and discuss behavioral, developmental, genetic and populational evidences that could explain the morphological patterns observed. The main results of the thesis are: (1) wing shape in males seems to be adapted for long lasting flights, with high energetic efficiency, while wing shape of females seems to be adapted for short flights, with improved maneuverability; (2) males have a more numerous mating behavior repertoire than females, which seems to be directly related to attempts of genital coupling; (3) males court and actively seek for mates (patrooling strategy); (4) females seem to have a decisive role in the copulatory success of males, since the intensity of male courtship does not seem to influence male copulatory success; (5) males with less variable behavioral patterns during courtship seem to have greater copulatory success; (6) large and small males court receptive females in the same way, suggesting that they do not use alternative strategies to compensate for effects caused by small body sizes; (7) the male size does not seem to influence female choice during courtship, (8) there is no direct competition between males, with agonistic behavior; (9) wing size has a moderate genetic basis; (10) genetic correlation between males and females, for some wing traits, seems to be imperfect, which could indicate or allow the action of sexual selection on wing size and shape; (11) the genetic correlation between forewings and hindwings is low, suggesting some genetic independence between the two sets of wings; (12) wing size has significant variation among populations and seasons and is strongly influenced by diet and temperature during development. Considering these evidences, the differential equilibrium model of evolution could be used to explain the sexual size dimorphism observed, since it affects life histories, ecology and behavior. Thus, the sexual size dimorphism in Dryas iulia alcionea could be an epiphenomenon resulting from selective forces acting differently on males and females.

Dryas iulia alcionea é uma espécie de borboleta que apresenta dimorfismo sexual em relação à coloração e ao tamanho das asas. Estudos em populações naturais mostraram que a variação no tamanho das asas dos machos é inferior a das fêmeas, sugerindo a ação de forças seletivas sobre a variabilidade das asas dos machos. Nesta tese, são apresentadas e discutidas evidências comportamentais, de desenvolvimento, genéticas e populacionais que podem explicar parcialmente os padrões morfológicos observados. Os principais resultados da tese são: (1) a forma das asas dos machos parece ser adaptada para vôos de longa duração, com alta eficiência energética, enquanto a forma das asas das fêmeas seria adaptada para vôos curtos, com alta manobrabilidade; (2) o repertório comportamental dos machos é maior do que o das fêmeas e diretamente relacionado à tentativa de efetuar cópula; (3) os machos buscam e cortejam ativamente as fêmeas (estratégia de patrulhamento); (4) as fêmeas parecem ter um papel decisivo no sucesso copulatório dos machos, já que a intensidade do cortejo dos machos parece não influenciar o sucesso copulatório; (5) os machos com padrões comportamentais menos variáveis parecem ter maior sucesso copulatório; (6) machos grandes e pequenos se comportam da mesma maneira frente a fêmeas receptivas, sugerindo que não existam estratégias alternativas para compensar efeitos causados por tamanhos corporais diminutos; (7) o tamanho dos machos não parece influenciar a escolha das fêmeas; (8) não há disputa direta entre machos (comportamento agonístico); (9) o tamanho das asas é uma característica com um moderado fator genético; (10) a correlação genética entre as características das asas dos machos e fêmeas é imperfeita, o que permitiria ou indicaria a ação de seleção sobre o dimorfismo sexual de tamanho das asas; (11) a correlação entre características das asas anteriores e posteriores é baixa, sugerindo uma considerável independência genética entre as características dos dois conjuntos de asas; (12) o tamanho apresenta significativa variação entre populações e estações do ano, sendo fortemente influenciado pelos recursos alimentares e temperatura durante o desenvolvimento larval. Com essas evidências, o modelo do equilíbrio diferencial de evolução poderia ser utilizado para explicar o dimorfismo sexual de tamanho observado, já que afeta as histórias de vidas, ecologia e comportamento. Assim, o dimorfismo sexual em D. i alcionea seria um epifenômeno resultante de forças seletivas atuado diferentemente sobre machos e fêmeas. / Dryas iulia alcionea is a butterfly species that shows sexual dimorphism in relation to wing color and size. Studies of natural populations showed that the variation in wing size in males is lower than in females, suggesting the action of selective forces on wing size variation in males. In this thesis, I present and discuss behavioral, developmental, genetic and populational evidences that could explain the morphological patterns observed. The main results of the thesis are: (1) wing shape in males seems to be adapted for long lasting flights, with high energetic efficiency, while wing shape of females seems to be adapted for short flights, with improved maneuverability; (2) males have a more numerous mating behavior repertoire than females, which seems to be directly related to attempts of genital coupling; (3) males court and actively seek for mates (patrooling strategy); (4) females seem to have a decisive role in the copulatory success of males, since the intensity of male courtship does not seem to influence male copulatory success; (5) males with less variable behavioral patterns during courtship seem to have greater copulatory success; (6) large and small males court receptive females in the same way, suggesting that they do not use alternative strategies to compensate for effects caused by small body sizes; (7) the male size does not seem to influence female choice during courtship, (8) there is no direct competition between males, with agonistic behavior; (9) wing size has a moderate genetic basis; (10) genetic correlation between males and females, for some wing traits, seems to be imperfect, which could indicate or allow the action of sexual selection on wing size and shape; (11) the genetic correlation between forewings and hindwings is low, suggesting some genetic independence between the two sets of wings; (12) wing size has significant variation among populations and seasons and is strongly influenced by diet and temperature during development. Considering these evidences, the differential equilibrium model of evolution could be used to explain the sexual size dimorphism observed, since it affects life histories, ecology and behavior. Thus, the sexual size dimorphism in Dryas iulia alcionea could be an epiphenomenon resulting from selective forces acting differently on males and females.

One of the prominent features in sediment sequences formed around the AllerOd-Younger Dryas transition (c. 12.9-12.8 ka bp) in North America is a dark layer of organic-rich material, i.e. the black mat. The black mat sequences in southeast Arizona contain a thin sandy basal layer corresponding to the lower Younger Dryas boundary. Trace element concentrations in the lower Younger Dryas boundary sediments, in the black mat, in the host sediments, and in charcoal from Western Europe and southeast Arizona were studied using LA-ICP-MS. The black mat samples and samples of the underlying host sediments display compositions similar to the average continental crust, while the sediments from the lower Younger Dryas boundary are enriched in rare earth elements, Ni, and Co whereas Ta, Nb, Zr, and Hf are depleted relative to the rare earth elements. Such a difference in compositions between the lower Younger Dryas boundary sediments and other sediments points to a short enigmatic event, which changed conditions of sedimentation just before the onset of the Younger Dryas cooling. The presence of products of biomass burning of still unknown origin is suggested on the basis of trace element features of sediments from the lower Younger Dryas boundary.

The dryad Minois dryas, described in 1763 by Giovanni Antonio Scopoli, belogs to our endangered species of butterflies. Its expansion today is restricted to a few localities in Central and Southern Bohemia and Southern Moravia only. Renewal and preservation of appropriate types of biotopes and research of its autecology and bionomy play the key roles in conservation of this species. The intention of my thesis was to identify host plants of Minois dryas caterpillars, to find out which grass is the most preferred one and to verify the correctness of hypothesis that the most preferred plant is also dominant from the range of potential host plants in the chosen area (a meadow in the vicinity of Žehuň in Central Bohemia). In the first part of experiment caterpillars were offered grasses collected in Žehuň. Plants which were eaten by caterpillars, were determined as host plants. According to results of this stage the host plants of caterpillars in the Czech republic are Dactylis glomerata, Bromus erectus, Festuca rubra, Arrhenatherum elatius and Carex acutiformis. In the second part of experiment caterpillars were offered all grasses evaluated in the first part as host plants and frequency of eaten / untouched leaves was recorded. Results identified Bromus erectus as the most desired grass and statistical proved there was a strong dependance among the plants . As Bromus erectus is indeed the most dominant grass in the location (approx. 30 % of all grasses), the hypothesis was confirmed. The experiment contributed with some other knowledge about dryad's bionomy. Observations confirmed that caterpillars pupate at the turn of June and July, primarilly at night. Larvae pupates in or on the ground. I did not notice any silk spinning during the time of pupation which is mentioned by Beneš et al. (2002). The pupal stage lasted 22 -- 23 days. Butterflies hatched in the morning. Imagos chose red watermelon as a food in most cases which proves that adults prefer red colour while deciding on their food (Vrabec et al., 2007).

The objective of this study is to investigate the effect of Atlantic meridional overturning circulation (AMOC) changes on tropical coupled ocean-atmosphere system via oceanic and atmospheric processes. A suite of numerical simulations have been conducted and the results show that both oceanic and atmospheric circulation changes induced by AMOC changes can have a profound impact on tropical sea surface temperature (SST) and sea surface salinity (SSS) conditions, but their dominance varies in different parts of the tropical oceans. The oceanic process has a dominant control on SST and SSS response to AMOC changes in the South Tropical Atlantic, while the atmospheric teleconnection is mainly responsible for SST and SSS changes over the North Tropical Atlantic and Pacific Oceans during the period of reduced AMOC. The finding has significant implication for the interpretation of the paleotemperature reconstructions over the southern Caribbean and the western Tropical Atlantic regions during the Younger Dryas. It suggests that the strong spatial inhomogeneity of the SST change revealed by the proxy records in these regions may be attributed to the competing oceanic and atmospheric processes that dominate the SST response. Similar mechanisms may also explain the reconstructed paleo-salinity change in the tropical Atlantic, which shows a basin-wide increase in SSS during the Younger Dryas, according to recent paleo climate studies. Finally, we show that atmospheric teleconnection induced by the surface cooling of the North Atlantic and the North Pacific in response to a weakened AMOC, is a leading physical mechanism that dictates the behavior of El Nino/Southern Oscillation (ENSO) response to AMOC changes. However, depending on its origin, the atmospheric teleconnection can affect ENSO variability in different ways. The atmospheric process associated with the North Atlantic cooling tends to enhance El Nino occurrence with a deepened mean thermocline depth in the eastern Pacific, whereas the atmospheric process associated with the North Pacific cooling tends to produce more La Nina events with a reduced mean thermocline depth in the eastern Pacific. Preliminary analysis suggests that the change in ENSO characteristics is associated with the change in internal atmospheric variability caused by the surface cooling in the North Atlantic and North Pacific. Complex nature of the underlying dynamics concerning the effect of the AMOC on ENSO calls for further investigation into this problem.

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