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Understanding why some species coexist and others do not remains one of the fundamental challenges of ecology. While several lines of evidence suggest that closely related species are unlikely to occupy the same habitat because of competitive exclusion, there are many cases where closely related species do co-occur. Research comparing sympatric and allopatric populations of co-occurring species provides a framework to understand the role of phenotypic diversification in species coexistence. In this study I focus on the livebearing fish Poeciliopsis baenschi and ask if differences in phenotypic traits among populations can be explained by the presence or absence of the congeneric species P. turneri. I focus on phenotypic divergence in life history traits and in body shape, two sets of integrated traits likely to respond to variation in competition. Additionally, I compare explore the effects of sympatry and allopatry on sexual dimorphism. I take advantage of a natural experiment in western Mexico where P. baenschi co-occur with P. turneri in some locations (sympatric populations) but also exist in isolation in other locations (allopatric populations). My results show that sympatric populations of P. baenschi differed significantly in life history traits and body shape when compared to their allopatric counterparts. Additionally, the amount of sexual dimorphism differed between sympatric and allopatric populations of P. baenschi, suggesting different constraints might exist in sympatry and allopatry for sexual dimorphism. Lastly, I explore my results in the context of trait evolution as it relates to species coexistence.

Failing public high schools are a perpetual limitation to community sustainability. Conversely, economically disadvantaged communities more often produce schools with reduced academic performance. Unfortunately, comprehensive community-based remedies are generally outside the scope of a school district's control. Social disorganization theory attributes variations in crime and delinquency to a breakdown in communal structure and relationships. Applied in a similar manner, social disorganization has also been associated with lower student achievement. This research examined how social disorganization is associated with Florida public high school academic performance in a two phase analysis at the community and school district levels. In addition, the research tested a potential moderating effect of receiving the Five Star School Award, recognizing family and community involvement, and Florida public high school academic performance with social disorganization factors simultaneously considered. In the first phase, the study used a cross-sectional, non-experimental design analyzing secondary data by structural equation modeling (SEM) at the community-level. For the second phase, the study used a cross-sectional, non-experimental design analyzing aggregated secondary data in multiple linear regressions assessing statistically significant associations between social disorganization predictors and school academic performance variables at the school district-level. SEM analysis found a statistically significant and large negative association between the social disorganization factors residential mobility, single-parent households, socio-economic status and percentage of divorced or separated persons, and Florida public high school academic performance at the community-level. Also at the community-level, results showed that receiving the Five Star School award for satisfying family and community involvement criteria had a statistically significant but small positive association with Florida public high school performance when social disorganization factors were simultaneously considered. At the district or county level, multiple regression analyses found relevant negative associations between social disorganization predictors low median income and ethnic heterogeneity and school district average FCAT scores and Adequate Yearly Progress (AYP) percentages. The study results reinforce existing neighborhood deprivation and social disorganization literature and articulate the need for a community-based approach to improve high school academic performance. Finally, the research suggests prominent education policy reforms may exacerbate social disorganization in communities and proposes alternative policy implementations.

Evolutionäre Herangehensweisen hatten in der Persönlichkeitspsychologie nicht den gleichen Erfolg wie in anderen Bereichen der Psychologie. In dieser Dissertation werden zwei alternative evolutionäre Herangehensweisen an die Persönlichkeitspsychologie diskutiert und angewendet. Die evolutionsgenetische Herangehensweise fragt, warum genetische Varianz in Persönlichkeitsunterschieden existiert. Im ersten Teil dieser Dissertation werden verschiedene evolutionsgenetische Mechanismen, die genetische Varianz erklären können, verglichen. Auf Grundlage evolutionsgenetischer Theorie und empirischen Befunden aus der Verhaltensgenetik und Persönlichkeitspsychologie wird geschlussfolgert, dass ein Mutations-Selektions-Gleichgewicht genetische Varianz in Intelligenz gut erklären kann, während ausgleichende Selektion durch Umweltheterogenität die plausibelste Erklärung für genetische Unterschiede in Persönlichkeitseigenschaften ist. Komplementär zur evolutionsgenetischen Herangehensweise beginnt die „Life History“-Herangehensweise damit, wie Menschen ihre Ressourcen in evolutionär relevante Lebensbereiche investieren. Im zweiten Teil der Dissertationsschrift wird diese Herangehensweise am Beispiel von Investitionsunterschieden in Langzeit- versus Kurzzeit-Paarungstaktiken (wie im Konstrukt der Soziosexualität abgebildet) erläutert. Zwei neue Maße zur Erfassung von Soziosexualitätskomponenten werden vorgestellt. Während das revidierte Soziosexuelle Orientierungsinventar (SOI-R) ein Fragebogen zur Erfassung der Facetten „Verhalten“, „Einstellung“ und „Begehren“ ist, wurde mit dem Single-Attribute Impliziten Assoziationstest (SA-IAT) eine neue Methode zur indirekten Erfassung impliziter Soziosexualität entwickelt. Beide Maße zeigten konkurrente Validität in Onlinestudien, aber nur der SOI-R erwies sich als prädiktiv für Paarungstaktiken, einschließlich beobachtetem Flirtverhalten sowie der Zahl der Sexualpartner und Veränderungen im Beziehungsstatus innerhalb der nächsten 12 Monate. / Evolutionary approaches have not been as successful in personality psychology as they were in other areas of psychology. In this thesis, two alternative evolutionary approaches to personality psychology are discussed and applied. The evolutionary genetic approach asks why genetic variance in personality differences exists. In the first part of this thesis, three evolutionary genetic mechanisms that could explain genetic variance in personality differences are assessed: selective neutrality, mutation-selection balance, and balancing selection. Based on evolutionary genetic theory and empirical results from behavior genetics and personality psychology, it is concluded that selective neutrality is largely irrelevant, that mutation-selection balance seems best at explaining genetic variance in intelligence, and that balancing selection by environmental heterogeneity seems best at explaining genetic variance in personality traits. Complementary to the evolutionary genetic approach, the life history approach starts with how people allocate their resources to evolutionarily relevant life tasks. In the second part of this thesis, differences in the allocation to long-term versus short-term mating tactics (as reflected in the construct of sociosexuality) are used as a case to exemplify this approach. Two new measures for the assessment of sociosexuality components are presented. While the revised Sociosexual Orientation Inventory (SOI-R) is a questionnaire that assesses the facets Behavior, Attitude and Desire, the sociosexuality Single-Attribute Implicit Association Test (SA-IAT) is a new methodic development aimed to assess implicit sociosexuality indirectly. Both measures showed concurrent validity in online studies, but only the SOI-R facets were predictive of mating tactics, including observed flirting behavior, as well as for the number of sexual partners and changes in romantic relationship status over the following 12 months.

Résumé : La reproduction entraîne des dépenses énergétiques importantes chez les femelles mammifères. Ces dépenses sont supposées diminuer l'énergie disponible pour d'autres traits positivement corrélés à l'aptitude phénotypique et augmenter les besoins d'alimentation. Toutefois, des différences individuelles dans la capacité d'acquisition et d'allocation peuvent masquer l'impact négatif de l'effort reproducteur. La manipulation expérimentale de l'effort reproducteur et le contrôle statistique des effets individuels sont deux approches puissantes et complémentaires mises en œuvre dans le cadre de mon étude afin de contrôler pour l'hétérogénéité individuelle. Elles ont permis de montrer clairement un coût de la reproduction chez le kangourou gris de l'Est (Macropus giganteus). Dans un premier temps, nous avons trouvé que le coût de la reproduction affectait le montant d'énergie alloué à certaines fonctions somatiques (CHAPITRE I). L'effort reproducteur diminuait le gain de masse et la croissance des jambes pour des intervalles de capture supérieurs à deux ans. Chez les femelles non manipulées, un effet négatif sur le gain de masse était aussi observable pour un intervalle inférieur à 3 ans. À l'échelle de deux événements successifs de reproduction, le gain de masse et dans une moindre mesure la croissance des bras, mais non des jambes diminuaient avec un effort reproducteur plus important à la précédente reproduction. Ensuite, nous avons démontré qu'il y avait un coût de la reproduction en terme de futur succès reproducteur (CHAPITRE II). Les individus dont l'effort reproducteur avait été diminué expérimentalement produisaient davantage de jeunes qui survivaient au stade 'LPY', âgés approximativement de 7 mois, que les femelles contrôles. Ils diminuaient également davantage leur taux de reproduction en allongeant l'intervalle entre les naissances, mais la survie au sevrage n'était pas affectée. Le CHAPITRE III montre que les femelles adaptaient leur comportement alimentaire en fonction de leur statut reproducteur. En comparaison avec les individus manipulés ou ayant perdu leur jeune, les femelles allaitantes augmentaient leur temps passé à s'alimenter durant la journée, l'intensité de leurs bouchées et de leur mastication sans impliquer de compromis avec la vigilance. Nous avons aussi découvert que la survie au sevrage du jeune précédent menait à une augmentation du taux de bouchées pour l'année en cours. Les CHAPITRES I et II ont mis en évidence l'effet non négligeable des différences individuelles sur la détection des coûts de la reproduction. En effet, en l'absence de manipulation expérimentale ou de contrôle statistique, aucun compromis n'était détecté autant en terme de croissance que de prochaine reproduction. Au contraire, des corrélations positives entre l'effort reproducteur et les autres traits ont été trouvées. Le CHAPITRE I suggérait notamment que cette variabilité du succès reproducteur était liée à l'hétérogénéité individuelle dans le gain de masse maternelle qui augmentait la survie du jeune. Dans le CHAPITRE II, une corrélation positive entre les probabilités d'avoir un 'LPY' lors de deux événements successifs de reproduction suggérait que certaines femelles étaient capables de mener à bien ou non leur reproduction, mais cela indépendamment de l'effort reproducteur précédent. Enfin dans le dernier CHAPITRE (III), l'effet aléatoire était significatif dans l'analyse de différents comportements d'alimentation, ce qui pourrait être lié aux différences de gain de masse des femelles présentées dans le CHAPITRE I. Certaines contraintes individuelles affectant le coût de la reproduction ont été identifiées. La masse et la condition corporelle augmentaient le succès reproducteur et diminuaient l'intervalle entre deux naissances successives (CHAPITRES I et II), mais contrairement à de précédentes études le comportement d'alimentation des femelles n'était pas affecté par leur masse (CHAPITRE III). L'âge des individus avait également une influence. Les jeunes femelles croissaient davantage, avaient aussi une prise alimentaire plus importante et subissaient un coût de reproduction supérieur. Ce dernier se traduisait par un taux d'échec plus élevé à la reproduction suivante si les jeunes femelles avaient eu un jeune l'année précédente (CHAPITRES I, II et III). Des contraintes environnementales fortes influençaient la reproduction des femelles. La croissance, le succès reproducteur, l'intervalle entre les naissances et les comportements d'alimentation variaient suivant le site et l'année d'étude. Le site du Promontory et l'année 2011 apparaissaient particulièrement limitants. En effet en 2011, le gain de masse et le succès reproducteur ont diminué et l'intervalle de naissance et la prise de nourriture pour les femelles allaitantes ont augmenté (CHAPITRE I,II et III). Nous cherchions également à mettre au jour une allocation différentielle des mères suivant le sexe de leur jeune. Si le coût supérieur d'avoir un mâle par rapport à une femelle était évident quant aux taux de bouchées (CHAPITRE III), il s'est avéré plus difficile à détecter sur d'autres traits. À Anglesea, les jeunes mères avaient moins de probabilité d'avoir un jeune qui atteigne le stade 'LPY' après avoir eu un fils qu'une fille (CHAPITRE II). Toutefois, des résultats contraires à nos attentes ont été trouvés, du moins au premier abord, sur la croissance et le succès reproducteur subséquent. Ainsi, les femelles qui avaient eu une fille perdaient davantage de masse (CHAPITRE I) et avaient généralement une probabilité moindre de produire un jeune qui atteigne le stade 'LPY' ou qui soit sevré par la suite (CHAPITRE II). En revanche, l'intervalle de naissance n'était pas différent suivant le sexe du jeune alors qu'il était fortement affecté par le coût de la reproduction démontré grâce à la manipulation, invoquant une autre explication qu'un coût supérieur des filles par rapport aux fils. En effet, les femelles qui étaient en mauvaise condition corporelle gagnaient de la masse quand elles produisaient une fille, mais pas un fils (CHAPITRE I). De surcroît, les jeunes mères avaient moins de chances de sevrer un jeune à l'événement de reproduction suivant si elles avaient eu un fils plutôt qu'une fille, et le succès reproducteur des mères des fils n'était plus différent de celui des mères des filles dans les années plus difficiles (CHAPITRE II). Enfin, les mères des fils augmentaient la quantité de nourriture ingérée si elles avaient sevré un jeune l'année précédente, mais les mères des filles la diminuaient. Ces différents résultats suggéraient fortement qu'un ajustement du sexe-ratio était utilisé quand les ressources individuelles ou environnementales contraignaient davantage la reproduction. En conclusion, pour limiter le décalage entre les besoins énergétiques et la disponibilité en nourriture, les femelles chez le kangourou gris de l'Est pourraient modifier l'allocation de leurs ressources à la reproduction en reportant la prochaine mise bas et en produisant un jeune du sexe le moins coûteux en accord avec les contraintes individuelles et environnementales. Ces résultats soulignent l'importance d'études avec un suivi individuel sur plusieurs années afin de pouvoir comprendre la variabilité des stratégies de reproduction et leurs conséquences sur la dynamique des populations. // Abstract : Reproduction in living beings, particularly in female mammals that produce milk, is costly, potentially involving trade-offs with life-history traits if resources are limited and an increase in foraging effort. Individual differences may, however, hide the negative effects of this cost on life-history traits. I used two powerful and complementary approaches, to deal with individual heterogeneity: experimental manipulation of reproductive effort and statistical control of individual effect. Using both approaches, I investigated the effect of presence, size and sex of young on growth, subsequent reproduction and individual foraging behaviours of females. I used data of tagged free-ranging eastern grey kangaroos (Macropus giganteus) collected over six years at five study sites in Victoria, Australia. There was a clear cost of reproduction. Reproductive effort decreased mass gain and limb growth for inter-capture intervals greater than two years. Over two successive reproductive events, mass gain and arm growth were reduced but leg growth was independent of reproductive effort (CHAPTER II).In addition, survival to Large Pouch Young ('LPY') stage, about 7 months of age, was higher and birth rate lower in manipulated compared to control females but survival to weaning was not affected (CHAPTER III). CHAPTER IV shows that lactating females cope with current reproductive costs by increasing ivtime spent foraging as well as bite and chewing rates without decreasing vigilance comparedto non lactating ones. Bite rate was also greater for females that weaned a young at the previous reproductive event. My study supports reproductive cost hypothesis while showing substantial individual differences. To limit mismatch between energetic needs and resource availability, females of eastern grey kangaroo could modify resource allocation to reproduction by delaying birth date of subsequent young and producing the less costly sex according to individual and environmental constrains. My thesis shows the importance of experimental approach and individual monitoring over multiple years to understand the diversity of reproductive strategies and their consequences in evolutionary ecology and population dynamic.

A perspectiva evolucionista entende a propensão humana ao risco como estratégia comportamental selecionada para responder a certas dicas ambientais e individuais sobre a disponibilidade de recursos. Dentre as dicas ambientais, a imprevisibilidade é um dos aspectos mais influentes na propensão ao risco. No entanto, não há consenso sobre a importância da imprevisibilidade real do ambiente atual ou de um viés perceptivo sobre a imprevisibilidade, construído ao longo do desenvolvimento. Além disso, é importante considerar o estudo destas relações de forma multidimensional, a fim de se analisar os vários aspectos que influenciam o risco (social, cultural, individual e contextual) e a imprevisibilidade (perceptiva, objetiva e contextual). Esta tese teve como objetivos: (1) comparar diferentes instrumentos/metodologias de mensuração do risco relacionadas a diferentes formas de envolvimento do participante em situação de tomada de decisão; (2) investigar as relações da percepção de imprevisibilidade do ambiente infantil, da percepção de imprevisibilidade do ambiente atual e da imprevisibilidade objetiva do ambiente atual com as taxas de propensão ao risco; e (3) diferenciar grupos sexuais e grupos experimentais de imprevisibilidade contextual imediata manipulada quanto à variação das taxas de propensão ao risco. Esta pesquisa constou de etapa de construção de instrumento de ativação contextual (a partir de grupos focais; n=35), etapa de pré-teste (n=46) e etapa de coleta propriamente dita (n=211). Tanto no pré-teste quanto na coleta de dados foram usados os mesmos instrumentos: além de questionário sociodemográfico e questionário sobre marcos futuros, usamos instrumentos de imprevisibilidade (EIFI, dados objetivos e ativação contextual por meio de vídeos) e de propensão ao risco (EPRE, jogo driving a car e jogo de cartas). A coleta ocorreu individualmente em setting experimental, com grupos amostrais: 120 participantes eram mulheres (m=21,60 anos; dp=2,19) e 91 eram homens (m=21,46 anos; dp=2,0); 74 participantes compuseram o grupo somático, 78 o grupo reprodutivo e 59 o grupo controle. Os resultados apoiaram a hipótese da relação entre a percepção de imprevisibilidade na infância e a propensão ao risco em etapas mais maduras da vida. Entretanto, esta relação é acompanhada de outros fatores diretamente, tal como a expectativa de vida, e indiretamente, tais como a imprevisibilidade objetiva atual, a percepção de imprevisibilidade atual reprodutiva e o lócus de controle externo. Médias de risco foram diferenciadas por características sexuais, enquanto características contextuais diferenciam a estratégia de resposta ao risco, ou seja, sob ativação contextual o indivíduo recorre mais fortemente à percepção de imprevisibilidade infantil para responder à propensão ao risco do que à expectativa de vida. Além disso, este trabalho contribuiu para a construção e desenvolvimento de instrumentos válidos para o estudo da propensão ao risco voltados para população brasileira / According to the Evolutionary Theory, risk-taking is an evolved behavioral strategy to deal with individual and environmental cues about the availability of resources. Among the environmental cues, unpredictability is one of the most influential on risk-taking. However, there is no consensus whether the actual unpredictability of the current environment or a developmentally acquired perceptual bias of the unpredictability is more important. Furthermore, it is important to consider the study of these relationships in a multidimensional way in order to analyze the various aspects that influence risk (social, cultural, individual and contextual) and unpredictability (perceptive, objective and contextual). This project aimed at: (1) comparing different risk-taking instruments/measures related to different forms of participant involvement in decision-making situations; (2) investigating the relationships between perception of unpredictability in the childhood, perception of unpredictability in current life and objective unpredictability with risk-taking; and (3) differentiating gender and experimental groups with handling contextual unpredictability on risk-taking averages. This research included a phase for the development of an activation of unpredictability instrument (from focus groups, n = 35), stage of pre-test (n=46), and stage of data collection (n=211). Both for the pre-test and for data collection the same instruments were used: a sociodemographic questionnaire, a questionnaire of future milestones, instruments of unpredictability (EIFI, objective data and contextual activation through videos), and instruments of risk-taking (EPRE, game driving a car and cards game). Data collection occurred individually in experimental setting with sample groups: 120 participants were women (mean = 21.60 years, sd= 2.19) and 91 were men (m= 21.46 years, sd=2.0); 74 participants in the somatic group, 78 in the reproductive group and 59 in the control group. The results supported the hypothesized relationship between early childhood perception of unpredictability and risk-taking in mature stages of life. However, this relationship is directly accompanied by other factors, such as life expectancy, and indirectly, such as the objective unpredictability, perception of current reproductive unpredictability and external locus of control. Risk-taking means were differentiated by sex, while contextual characteristics differentiated the strategy of risk response, i.e., under contextual activation individuals use more strongly the childhood perception of unpredictability to respond to risk-taking than to life expectancy. Furthermore, this study has contributed to the construction and development of valid instruments for the study of risk-taking in the Brazilian population

Free-living marine nematodes are the most ubiquitous, abundant and diverse meiofaunal component of benthic communities. These are excellent model organisms, due to its short life span, wide availability and feasibility to cultivate with minimum laboratory facilities. In this study, a population of Diplolaimella dievengatensis Jacobs 1991 (Nematoda, Monhysteridae) from the relatively Pristine estuary of the Guaratuba River in São Paulo, Brazil was isolated and cultivated. The goals were; i- to apply an integrative taxonomic approach in order to compare this population from Brazil with another from the species type-locality in the Belgian Coast, with regard to morphological, life-cycle and the 18S gene of the rDNA molecular data; and ii- to compare, at the light of life history theory, the responses of life history parameters such as; fecundity, growth and survivorship of D. dievengatensis (here as a slower species) and Litoditis marina (Bastian, 1865) (Nematoda, Rhabditidae) (as a faster species) under sublethal exposition to the sodium dodecyl sulfate (SDS) surfactant. The population from Brazil was similar to that from Belgium coast in all parameters. Although morphometric analyses considered the Brazilian D. dievengatensis isometrically larger than the Belgian population regarding some characters, the presence of all diagnostic characters confirmed the similarity of both species. The life-cycle, hatching time, final body length, and biomass parameters were similar in both populations, in which females were larger than males. The population growth, measured as intrinsic rate of natural increase was slightly higher for the D. dievengatensis from Brazil (rm=0.41), than the European population (rm =0.348). Molecular comparison on Genbank showed 99.4% of similarity between both populations, indicating therefore, that D. dievengatensis from Brazil is similar to those from Belgium. In the chapter ii, both species responded differently to SDS exposition. Growth and reproduction rate of D. dievengatensis surprisingly were enhanced at low and intermediate concentrations of SDS (0.001 and 0.003%), while for L. marina these parameters were reduced in all SDS concentrations tested (0.001, 0.003 and 0.006%). The SDS did not affect the survivorship of adults of the slower specie. On the other hand, survivorship of adults of the fast species was significantly affected by SDS and this effect was dependent on adult gender, with reduced rates of males exposed to 0.006% SDS. Although both species are located nearby along the fast-slow continuum, they responded distinctly to of the toxic SDS effect. Effects over L. marina met the trend of faster species in allocating fewer investments in defenses against physiological injuries and on their own somatic maintenance. We propose that the apparent lower resistance of this faster species under stress at the individual level is balanced by their higher reproductive rates, conferring higher resilience to this species at the population level. Finally, it was demonstrated that the marine nematode D. dievengatensis is an important native model organism which can be used in a wide range of studies and experimental tests. Identifying and understanding differential effects of stress in the context of life-history theory is an important aspect which enhanced our understanding about the threats posed by anthropogenic activities on natural communities / Nematodas marinhos de vida livre são o mais onipresentes, abundantes e diversos componentes da meiofauna em comunidades bênticas. São excelentes organismos modelo devido a seu curto ciclo de vida, ampla disponibilidade e viabilidade de cultivo com mínima estrutura laboratorial. Neste estudo, uma população de Diplolaimella dievengatensis Jacobs 1991 (Nematoda, Monhysteridae) do estuário relativamente prístino do rio Guaratuba, São Paulo, Brasil foi isolada e cultivada. Os objetivos foram: ii- aplicar uma abordagem taxonômica integrativa a fim de comparar esta população do Brasil com outra da localidade tipo dessa espécie, da costa da Bélgica, com relação à dados morfológicos, do ciclo de vida e molecular do gene 18S do rDNA; e ii-comparar, à luz da teoria da historia de vida, repostas de parâmetros do ciclo de vida tais como: fecundidade, crescimento e sobrevivência de D. dievengatensis (aqui como espécies mais lenta) e Litoditis marina (Bastian, 1865) (Nematoda, Rhabditidae) (como espécie rápida) sob exposição subletal ao surfactante dodecil sulfato de sódio (DSS) . A população do Brasil foi similar a da costa da Bélgica em todos os parâmetros. Embora analises morfométricas consideraram D. dievengatensis do Brasil isometricamente maior que a população belga em relação em algumas características, a presença de todos os caracteres diagnósticos confirmaram a similaridade de ambas as espécies. Os parâmetros de ciclo de vida, tempo de eclosão, comprimento corporal final e biomassa foram similares em ambas as populações, nas quais fêmeas foram maiores que machos. Crescimento populacional, mensurado como taxa intrínseca de crescimento natural foi ligeiramente mais alta para D. dievengatensisdo Brasil (rm=0.41), que para a população europeia (rm=0.348). Comparações moleculares no Genbank mostraram 99.4% de similaridade entre ambas populações, indicando portanto que a população do Brasil é similar a D. dievengatensis belga. No capítulo ii, ambas as espécies responderam distintamente a exposição ao SDS. Supreendentemente as taxas de crescimento e de reprodução de D. dievengatensis foram incrementadas sob concentrações mais baixas e intermediárias (0.001 e 0.003%), enquanto para L. marina esses parâmetros foram reduzidos em todas as concentrações de DSS testadas (0.001, 0.003 e 0.006%). O DSS não afetou a sobrevivência de adultos da espécie mais lenta. Por outro lado, a sobrevivência de adultos da espécie mais rápida foi significativamente afetada pelo SDS e esse efeito foi dependente do sexo, com taxas reduzidas em machos expostos a 0.006 % de DSS. Embora ambas as espécies estejam proximamente dispostas ao longo do gradiente \"rápido-lento\", elas responderam diferentemente ao efeito tóxico do DSS. Efeitos sobre L marina se enquadram no padrão de espécies mais rápidas ao alocar menores investimentos para as defesas contra danos fisiológicos e para sua própria manutenção somática. Nós propomos que a aparente menor resistência desta espécie rápida sob estresse ao nível individual é balanceada por suas altas taxas reprodutivas, conferindo mais alta resiliência a essa espécie ao nível populacional. Por fim, foi demonstrado que D. dievengatensis é um importante organismo modelo nativo que pode ser usado em uma ampla diversidade estudos e testes experimentais. Identificar e compreender diferentes efeitos do estresse dentro do contexto da teoria da história de vida é um aspecto importante, o qual tem aumentado nosso conhecimento sobre as ameaças de atividades antropogênicas sobre comunidades naturais

A perspectiva evolucionista entende a propensão humana ao risco como estratégia comportamental selecionada para responder a certas dicas ambientais e individuais sobre a disponibilidade de recursos. Dentre as dicas ambientais, a imprevisibilidade é um dos aspectos mais influentes na propensão ao risco. No entanto, não há consenso sobre a importância da imprevisibilidade real do ambiente atual ou de um viés perceptivo sobre a imprevisibilidade, construído ao longo do desenvolvimento. Além disso, é importante considerar o estudo destas relações de forma multidimensional, a fim de se analisar os vários aspectos que influenciam o risco (social, cultural, individual e contextual) e a imprevisibilidade (perceptiva, objetiva e contextual). Esta tese teve como objetivos: (1) comparar diferentes instrumentos/metodologias de mensuração do risco relacionadas a diferentes formas de envolvimento do participante em situação de tomada de decisão; (2) investigar as relações da percepção de imprevisibilidade do ambiente infantil, da percepção de imprevisibilidade do ambiente atual e da imprevisibilidade objetiva do ambiente atual com as taxas de propensão ao risco; e (3) diferenciar grupos sexuais e grupos experimentais de imprevisibilidade contextual imediata manipulada quanto à variação das taxas de propensão ao risco. Esta pesquisa constou de etapa de construção de instrumento de ativação contextual (a partir de grupos focais; n=35), etapa de pré-teste (n=46) e etapa de coleta propriamente dita (n=211). Tanto no pré-teste quanto na coleta de dados foram usados os mesmos instrumentos: além de questionário sociodemográfico e questionário sobre marcos futuros, usamos instrumentos de imprevisibilidade (EIFI, dados objetivos e ativação contextual por meio de vídeos) e de propensão ao risco (EPRE, jogo driving a car e jogo de cartas). A coleta ocorreu individualmente em setting experimental, com grupos amostrais: 120 participantes eram mulheres (m=21,60 anos; dp=2,19) e 91 eram homens (m=21,46 anos; dp=2,0); 74 participantes compuseram o grupo somático, 78 o grupo reprodutivo e 59 o grupo controle. Os resultados apoiaram a hipótese da relação entre a percepção de imprevisibilidade na infância e a propensão ao risco em etapas mais maduras da vida. Entretanto, esta relação é acompanhada de outros fatores diretamente, tal como a expectativa de vida, e indiretamente, tais como a imprevisibilidade objetiva atual, a percepção de imprevisibilidade atual reprodutiva e o lócus de controle externo. Médias de risco foram diferenciadas por características sexuais, enquanto características contextuais diferenciam a estratégia de resposta ao risco, ou seja, sob ativação contextual o indivíduo recorre mais fortemente à percepção de imprevisibilidade infantil para responder à propensão ao risco do que à expectativa de vida. Além disso, este trabalho contribuiu para a construção e desenvolvimento de instrumentos válidos para o estudo da propensão ao risco voltados para população brasileira / According to the Evolutionary Theory, risk-taking is an evolved behavioral strategy to deal with individual and environmental cues about the availability of resources. Among the environmental cues, unpredictability is one of the most influential on risk-taking. However, there is no consensus whether the actual unpredictability of the current environment or a developmentally acquired perceptual bias of the unpredictability is more important. Furthermore, it is important to consider the study of these relationships in a multidimensional way in order to analyze the various aspects that influence risk (social, cultural, individual and contextual) and unpredictability (perceptive, objective and contextual). This project aimed at: (1) comparing different risk-taking instruments/measures related to different forms of participant involvement in decision-making situations; (2) investigating the relationships between perception of unpredictability in the childhood, perception of unpredictability in current life and objective unpredictability with risk-taking; and (3) differentiating gender and experimental groups with handling contextual unpredictability on risk-taking averages. This research included a phase for the development of an activation of unpredictability instrument (from focus groups, n = 35), stage of pre-test (n=46), and stage of data collection (n=211). Both for the pre-test and for data collection the same instruments were used: a sociodemographic questionnaire, a questionnaire of future milestones, instruments of unpredictability (EIFI, objective data and contextual activation through videos), and instruments of risk-taking (EPRE, game driving a car and cards game). Data collection occurred individually in experimental setting with sample groups: 120 participants were women (mean = 21.60 years, sd= 2.19) and 91 were men (m= 21.46 years, sd=2.0); 74 participants in the somatic group, 78 in the reproductive group and 59 in the control group. The results supported the hypothesized relationship between early childhood perception of unpredictability and risk-taking in mature stages of life. However, this relationship is directly accompanied by other factors, such as life expectancy, and indirectly, such as the objective unpredictability, perception of current reproductive unpredictability and external locus of control. Risk-taking means were differentiated by sex, while contextual characteristics differentiated the strategy of risk response, i.e., under contextual activation individuals use more strongly the childhood perception of unpredictability to respond to risk-taking than to life expectancy. Furthermore, this study has contributed to the construction and development of valid instruments for the study of risk-taking in the Brazilian population

R??sum?? : La reproduction entra??ne des d??penses ??nerg??tiques importantes chez les femelles mammif??res. Ces d??penses sont suppos??es diminuer l'??nergie disponible pour d'autres traits positivement corr??l??s ?? l'aptitude ph??notypique et augmenter les besoins d'alimentation. Toutefois, des diff??rences individuelles dans la capacit?? d'acquisition et d'allocation peuvent masquer l'impact n??gatif de l'effort reproducteur. La manipulation exp??rimentale de l'effort reproducteur et le contr??le statistique des effets individuels sont deux approches puissantes et compl??mentaires mises en ??uvre dans le cadre de mon ??tude afin de contr??ler pour l'h??t??rog??n??it?? individuelle. Elles ont permis de montrer clairement un co??t de la reproduction chez le kangourou gris de l'Est (Macropus giganteus). Dans un premier temps, nous avons trouv?? que le co??t de la reproduction affectait le montant d'??nergie allou?? ?? certaines fonctions somatiques (CHAPITRE I). L'effort reproducteur diminuait le gain de masse et la croissance des jambes pour des intervalles de capture sup??rieurs ?? deux ans. Chez les femelles non manipul??es, un effet n??gatif sur le gain de masse ??tait aussi observable pour un intervalle inf??rieur ?? 3 ans. ?? l'??chelle de deux ??v??nements successifs de reproduction, le gain de masse et dans une moindre mesure la croissance des bras, mais non des jambes diminuaient avec un effort reproducteur plus important ?? la pr??c??dente reproduction. Ensuite, nous avons d??montr?? qu'il y avait un co??t de la reproduction en terme de futur succ??s reproducteur (CHAPITRE II). Les individus dont l'effort reproducteur avait ??t?? diminu?? exp??rimentalement produisaient davantage de jeunes qui survivaient au stade 'LPY', ??g??s approximativement de 7 mois, que les femelles contr??les. Ils diminuaient ??galement davantage leur taux de reproduction en allongeant l'intervalle entre les naissances, mais la survie au sevrage n'??tait pas affect??e. Le CHAPITRE III montre que les femelles adaptaient leur comportement alimentaire en fonction de leur statut reproducteur. En comparaison avec les individus manipul??s ou ayant perdu leur jeune, les femelles allaitantes augmentaient leur temps pass?? ?? s'alimenter durant la journ??e, l'intensit?? de leurs bouch??es et de leur mastication sans impliquer de compromis avec la vigilance. Nous avons aussi d??couvert que la survie au sevrage du jeune pr??c??dent menait ?? une augmentation du taux de bouch??es pour l'ann??e en cours. Les CHAPITRES I et II ont mis en ??vidence l'effet non n??gligeable des diff??rences individuelles sur la d??tection des co??ts de la reproduction. En effet, en l'absence de manipulation exp??rimentale ou de contr??le statistique, aucun compromis n'??tait d??tect?? autant en terme de croissance que de prochaine reproduction. Au contraire, des corr??lations positives entre l'effort reproducteur et les autres traits ont ??t?? trouv??es. Le CHAPITRE I sugg??rait notamment que cette variabilit?? du succ??s reproducteur ??tait li??e ?? l'h??t??rog??n??it?? individuelle dans le gain de masse maternelle qui augmentait la survie du jeune. Dans le CHAPITRE II, une corr??lation positive entre les probabilit??s d'avoir un 'LPY' lors de deux ??v??nements successifs de reproduction sugg??rait que certaines femelles ??taient capables de mener ?? bien ou non leur reproduction, mais cela ind??pendamment de l'effort reproducteur pr??c??dent. Enfin dans le dernier CHAPITRE (III), l'effet al??atoire ??tait significatif dans l'analyse de diff??rents comportements d'alimentation, ce qui pourrait ??tre li?? aux diff??rences de gain de masse des femelles pr??sent??es dans le CHAPITRE I. Certaines contraintes individuelles affectant le co??t de la reproduction ont ??t?? identifi??es. La masse et la condition corporelle augmentaient le succ??s reproducteur et diminuaient l'intervalle entre deux naissances successives (CHAPITRES I et II), mais contrairement ?? de pr??c??dentes ??tudes le comportement d'alimentation des femelles n'??tait pas affect?? par leur masse (CHAPITRE III). L'??ge des individus avait ??galement une influence. Les jeunes femelles croissaient davantage, avaient aussi une prise alimentaire plus importante et subissaient un co??t de reproduction sup??rieur. Ce dernier se traduisait par un taux d'??chec plus ??lev?? ?? la reproduction suivante si les jeunes femelles avaient eu un jeune l'ann??e pr??c??dente (CHAPITRES I, II et III). Des contraintes environnementales fortes influen??aient la reproduction des femelles. La croissance, le succ??s reproducteur, l'intervalle entre les naissances et les comportements d'alimentation variaient suivant le site et l'ann??e d'??tude. Le site du Promontory et l'ann??e 2011 apparaissaient particuli??rement limitants. En effet en 2011, le gain de masse et le succ??s reproducteur ont diminu?? et l'intervalle de naissance et la prise de nourriture pour les femelles allaitantes ont augment?? (CHAPITRE I,II et III). Nous cherchions ??galement ?? mettre au jour une allocation diff??rentielle des m??res suivant le sexe de leur jeune. Si le co??t sup??rieur d'avoir un m??le par rapport ?? une femelle ??tait ??vident quant aux taux de bouch??es (CHAPITRE III), il s'est av??r?? plus difficile ?? d??tecter sur d'autres traits. ?? Anglesea, les jeunes m??res avaient moins de probabilit?? d'avoir un jeune qui atteigne le stade 'LPY' apr??s avoir eu un fils qu'une fille (CHAPITRE II). Toutefois, des r??sultats contraires ?? nos attentes ont ??t?? trouv??s, du moins au premier abord, sur la croissance et le succ??s reproducteur subs??quent. Ainsi, les femelles qui avaient eu une fille perdaient davantage de masse (CHAPITRE I) et avaient g??n??ralement une probabilit?? moindre de produire un jeune qui atteigne le stade 'LPY' ou qui soit sevr?? par la suite (CHAPITRE II). En revanche, l'intervalle de naissance n'??tait pas diff??rent suivant le sexe du jeune alors qu'il ??tait fortement affect?? par le co??t de la reproduction d??montr?? gr??ce ?? la manipulation, invoquant une autre explication qu'un co??t sup??rieur des filles par rapport aux fils. En effet, les femelles qui ??taient en mauvaise condition corporelle gagnaient de la masse quand elles produisaient une fille, mais pas un fils (CHAPITRE I). De surcro??t, les jeunes m??res avaient moins de chances de sevrer un jeune ?? l'??v??nement de reproduction suivant si elles avaient eu un fils plut??t qu'une fille, et le succ??s reproducteur des m??res des fils n'??tait plus diff??rent de celui des m??res des filles dans les ann??es plus difficiles (CHAPITRE II). Enfin, les m??res des fils augmentaient la quantit?? de nourriture ing??r??e si elles avaient sevr?? un jeune l'ann??e pr??c??dente, mais les m??res des filles la diminuaient. Ces diff??rents r??sultats sugg??raient fortement qu'un ajustement du sexe-ratio ??tait utilis?? quand les ressources individuelles ou environnementales contraignaient davantage la reproduction. En conclusion, pour limiter le d??calage entre les besoins ??nerg??tiques et la disponibilit?? en nourriture, les femelles chez le kangourou gris de l'Est pourraient modifier l'allocation de leurs ressources ?? la reproduction en reportant la prochaine mise bas et en produisant un jeune du sexe le moins co??teux en accord avec les contraintes individuelles et environnementales. Ces r??sultats soulignent l'importance d'??tudes avec un suivi individuel sur plusieurs ann??es afin de pouvoir comprendre la variabilit?? des strat??gies de reproduction et leurs cons??quences sur la dynamique des populations. // Abstract : Reproduction in living beings, particularly in female mammals that produce milk, is costly, potentially involving trade-offs with life-history traits if resources are limited and an increase in foraging effort. Individual differences may, however, hide the negative effects of this cost on life-history traits. I used two powerful and complementary approaches, to deal with individual heterogeneity: experimental manipulation of reproductive effort and statistical control of individual effect. Using both approaches, I investigated the effect of presence, size and sex of young on growth, subsequent reproduction and individual foraging behaviours of females. I used data of tagged free-ranging eastern grey kangaroos (Macropus giganteus) collected over six years at five study sites in Victoria, Australia. There was a clear cost of reproduction. Reproductive effort decreased mass gain and limb growth for inter-capture intervals greater than two years. Over two successive reproductive events, mass gain and arm growth were reduced but leg growth was independent of reproductive effort (CHAPTER II).In addition, survival to Large Pouch Young ('LPY') stage, about 7 months of age, was higher and birth rate lower in manipulated compared to control females but survival to weaning was not affected (CHAPTER III). CHAPTER IV shows that lactating females cope with current reproductive costs by increasing ivtime spent foraging as well as bite and chewing rates without decreasing vigilance comparedto non lactating ones. Bite rate was also greater for females that weaned a young at the previous reproductive event. My study supports reproductive cost hypothesis while showing substantial individual differences. To limit mismatch between energetic needs and resource availability, females of eastern grey kangaroo could modify resource allocation to reproduction by delaying birth date of subsequent young and producing the less costly sex according to individual and environmental constrains. My thesis shows the importance of experimental approach and individual monitoring over multiple years to understand the diversity of reproductive strategies and their consequences in evolutionary ecology and population dynamic.

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