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En forêt tropicale humide Amazonienne, les facteurs gouvernant l'évolution des espèces d'arbres restent peu connus et continuellement débattus. En particulier, les micro-variations environnementales attirent beaucoup d'attention car elles induisent de profondes modifications de structure et composition des communautés. Les variations micro-environnementales associées à la topographie ont couramment été évoquées comme facteur de radiations adaptatives chez les espèces d'arbres. Cependant, l'hypothèse de l'adaptation locale n'a jamais été testée au niveau intra-spécifique chez les arbres de forêt amazonienne alors que l'on sait que la diversité génétique des arbres tropicaux est couramment structurée à faibles échelles spatiales par des processus neutres (en particulier du fait de restrictions de flux de gènes). Dans cette étude, j'ai étudié le processus de différentiation génétique d'une espèce d'arbre (Eperua falcata, Fabaceae) dans les paysages forestiers de Guyane française grâce à la combinaison d'une approche phénotypique (génétique quantitative) et d'une approche moléculaire (génétique des populations). Je me suis attachée à répondre à trois questions principales : 1) Comment se distribue la diversité génétique dans les paysages forestiers de Guyane française ? 2) Quelles forces évolutives sont impliquées dans le processus de différentiation génétique à faible échelle spatiale ? 3) Est-ce que le processus d'adaptation locale contribue à structurer la diversité génétique à faible échelle spatiale ? / In the tropical rainforest of Amazonia, the factors driving the evolution of tree species remain poorly understood, and the relative influence of neutral and adaptive processes is continuously debated. In particular, local habitat patchiness draws much attention, as profound changes in the structure and composition of forest communities occur among micro-habitats. Thus, micro-environmental variations related to topography have frequently been invoked as drivers of adaptive radiation leading to sympatric speciation in Neotropical trees. On one hand, the hypothesis of local adaptation has never been investigated at the intra-specific level, i.e. within species currently undergoing population differentiation; on the other hand, many tree species are genetically structured over local scales due to neutral processes, mainly limited gene flow (caused by restricted pollen and seed dispersal). In this study, I used populations of a common tree species of the Guiana Shield - Eperua falcata (Fabaceae) - to study how neutral and adaptive processes shape the distribution of genetic diversity across forest landscapes characterized by local micro-habitat patchiness. I asked three main questions by combining both phenotypic (quantitative genetics) and molecular (population genetics) approaches: 1) How is the genetic diversity structured in forest landscapes of French Guiana? 2) Which evolutionary drivers are relevant to explain the structure of genetic diversity at local scale? 3) Does local adaptation contribute to structure genetic diversity within continuous populations?

É inegável a importância do melhoramento genético. Na literatura reporta-se que na ausência do melhoramento a produtividade dos cultivos agrícolas poderia ter diminuído. Deste modo, é fundamental avaliar o progresso genético para otimizar a eficiência da seleção e avaliar as técnicas empregadas. O progresso genético foi estudado em várias culturas no Brasil e no mundo. Apesar de feitas interpretações do relacionamento entre caracteres, não foram encontrados na literatura métodos ou estimativas relacionadas ao progresso simultâneo quando mais de um caráter sofre seleção. Como os melhoristas se atém a seleção de mais de um caráter, ao estimar o progresso genético dever-se-ia considerar esse aspecto. Nesse sentido, vislumbrou-se a possibilidade de se reunir a informação de mais de um caráter, tal qual um índice em que restrições sobre o original de Smith representam os progressos individuais estimados. Isto posto, o objetivo deste trabalho foi estimar os progressos genéticos no melhoramento do tabaco para os caracteres de interesse e apresentar uma alternativa interpretativa de reunir os progressos individuais na estimativa do progresso simultâneo. Mensurou-se o progresso genético dos caracteres agronômicos e morfológicos ao longo de 40 anos de melhoramento de tabaco do grupo varietal Virginia pela avaliação de nove linhagens oriundas de quatro fases distintas no delineamento casualizado em blocos com quatro repetições em quatro locais representativos da cultura. Com base nas estimativas e no desenvolvimento teórico do índice com restrições apresentado, reuniram-se as estimativas referentes aos progressos individuais como uma forma de representar o progresso genético simultâneo. A análise de regressão mostrou ganhos significativos por era de 275,29kg há-1 para a produtividade de folhas curadas, o que representa um progresso de 10% da média do ciclo inicial. A altura de plantas, número de folhas expandidas, bem como a largura e comprimento das folhas também mostraram incrementos significativos. Devido à interação genótipos por ambientes, os progressos estimados na média dos quatro locais não são bons preditores dos progressos por local. O índice de qualidade geral e a remuneração do produtor não apresentaram os progressos esperados em razão de essas avaliações terem sido realizadas apenas nas fases finais da seleção. A estimativa do progresso simultâneo aferiu um incremento de 6% por era no cômputo dos caracteres avaliados e reflete o sucesso na seleção e melhoramento simultâneo desses caracteres. O índice desenvolvido não necessita arbitrar pesos econômicos, atende às restrições, e mostrou-se eficaz em reunir os progressos genéticos dos caracteres além de poder ser empregado com o propósito da seleção em níveis não independentes de seleção. / The importance of plant breeding is unquestionable. In the literature, it is reported that in the absence of crop improvement crop yield could have decreased. Therefore, it is crucial to evaluate the genetic progress in order to optimize the efficiency of the selection procedures and evaluate the employed techniques. Data on genetic progress were studied throughout the world as well as in Brazil. Besides the understanding of the underlying relationships between traits, there are no current methods or estimates regarding simultaneous progress, i.e., whenever more than one trait undergo selection. As the breeders generally carry out selection considering more than one trait, when estimating the genetic progress, this particular issue should be considered. In this context, it has become possible to summarize information from more than one trait, as an index, based on the classic Smith index with constraints which represent the estimates of individual traits progress. Thus, the objective of the present work was to estimate genetic progress in a tobacco breeding program and to present an interpretative and promising alternative to address the individual progress and hence estimate the simultaneous progress. The genetic progress of agronomic and morphological traits was estimated over a period of 40 years in which selection was carried out for obtaining superior inbred lines of the Virginia variety group. Nine inbred lines, derived from four distinct eras, were evaluated in randomized complete block designs with four replicates in four Brazilian representative sites of the tobacco crop. Based on both the results and theoretical developments of the constrained index, the estimates of individual progress were combined in order to represent the simultaneous genetic progress. The regression analysis showed a significant gain per era of 275.29kg ha-1 for cured leaf weight, corresponding to a progress of 10% relative to the estimated intercept. Traits such as plant height, expanded leaves, as well as width and length of leaves also showed a significant increase. Given the genotype by environment interaction, the estimated marginal progress of the four sites was not a good predictor of the progress at each site. On the other hand, the leaf quality index and the corresponding commercial value did not show the aimed trend due to the fact that both evaluations were performed at the final trials. The simultaneous progress increased the set of traits by 6% per era relative to the intercept. This reflects the sucess of selection and simultaneous improvement of traits. The proposed index does not require attributing economic weights, satisfies the restrictions, is effective in summarizing the genetic progress of multipletraits and can be applied considering multitrait selection through non independent culling levels.

Meliponiculture (or stingless beekeeping) is a powerful tool for sustainable economic development in the tropics. However, meliponiculture has many challenges as it lacks standardization in management and breeding practices. The aim of this thesis was to investigate stingless bee reproductive biology combined to management and breeding as background to meliponiculture improvement. In chapter 1, we performed a meta-analysis of heritability across the Hymenoptera in order to review current knowledge and discuss the challenges for bee breeding and conservation. In chapter 2, we assessed how sexual selection acts on male traits in the stingless bee Scaptotrigona aff. depilis and identified which traits may affect male fitness. In chapter 3, we estimated heritability and genetic correlations for the traits studied in the previous chapter, to understand how evolution shapes male traits and to identify important traits for breeding programs. Finally, in chapter 4 we investigated how the environment and long-term management influence colony productivity in Melipona subnitida (jandaíra), a commercially managed species in Northeastern Brazil. Our results revealed that morphological traits exhibit higher heritability estimates than fitness related traits, and in general, colony productivity traits showed potential for breeding. However, few studies are available for stingless bees yet. Male aggregations in S. aff depilis selected competitive males with higher quality sperm, indicating the importance of this mechanism in stingless bee mating biology. The studied male traits exhibited high heritability estimates, with exception of sperm length. Since aggregations selected males with shorter sperm, these results suggest selection for long-term sperm storage by queens and higher fertilization potential. The assessment of M. subnitida records revealed that honey production was affected by climate and management, and strategies to improve beekeeping practices were discussed. We believe this thesis provides important guidelines to establish successful stingless bee breeding programs / A meliponicultura, criação racional de abelhas sem ferrão, é uma poderosa ferramenta para o desenvolvimento econômico sustentável em regiões tropicais. No entanto, a prática da meliponicultura enfrenta diversos desafios, como a falta de padronização das técnicas de manejo e melhoramento genético. O objetivo desta tese foi investigar a biologia reprodutiva de abelhas sem ferrão aliada ao manejo e ao melhoramento genético, a fim de fornecer subsídios para o aprimoramento da meliponicultura. No capítulo 1, realizamos uma meta-análise sobre herdabilidade em Hymenoptera, a fim de compreender o conhecimento atual e os desafios associados ao melhoramento genético de abelhas e sua conservação. No capítulo 2, avaliamos como a seleção sexual atua em caracteres dos machos da espécie Scaptotrigona aff. depilis e identificamos quais caracteres podem influenciar o sucesso reprodutivo. No capítulo 3, estimamos a herdabilidade e correlações genéticas para os caracteres avaliados no capítulo anterior, a fim de entender como a evolução atua moldando os caracteres dos machos e quais desses caracteres podem ser utilizados em programas de melhoramento genético. Finalmente, no capítulo 4, investigamos o efeito do ambiente e do manejo na produtividade de colônias em Melipona subnitida (jandaíra), uma espécie manejada comercialmente no Nordeste brasileiro. Nossos resultados revelaram que caracteres morfológicos exibem estimativas de herdabilidade mais altas do que caracteres ligados ao sucesso reprodutivo. No entanto, poucos estudos com abelhas sem ferrão foram realizados até o momento. Agregações de machos em S. aff. depilis selecionaram machos mais competitivos que apresentaram maior qualidade espermática, indicando a importância desse mecanismo na biologia reprodutiva de abelhas sem ferrão. Os caracteres estudados apresentaram alta herdabilidade, com exceção do comprimento do espermatozoide. Como agregações selecionam machos com espermatozoides mais curtos, esses resultados sugerem seleção direcionada para um maior tempo de armazenamento do esperma pelas rainhas e maior potencial de fertilização. A avaliação dos registros de M. subnitida revelou que a produção de mel foi afetada pelo clima e pelo manejo, e estratégias a fim de melhorar as práticas da meliponicultura foram discutidas. Acreditamos que essa tese fornece importantes resultados para o estabelecimento de programas de melhoramento genético em abelhas sem ferrão

Os conceitos e métodos provindos das teorias de integração morfológica e de genética quantitativa formam o arcabouço teórico para o estudo da evolução de estruturas complexas, compostas de múltiplos caracteres que interagem entre si. Nesse trabalho, utilizamos o crânio como modelo de estrutura complexa e estudamos sua diversificação nas espécies de sapo do grupo Rhinella granulosa. As perguntas do trabalho foram: (1) A organização da (co)variação é similar entre as espécies?; (2) A organização da (co)variação é modular nas espécies, conforme expectativas baseadas em desenvolvimento ou função?; (3) Fatores externos, como filogenia e clima, estruturam a similaridade no padrão de covariação entre as espécies?; (4) A diversificação da morfologia média do crânio se deu por deriva ou seleção natural?; (5) A divergência na morfologia média do crânio está associada à variação climática entre as espécies?; e finalmente (6) Restrições evolutivas atuaram na divergência entre as espécies? Os espécimes foram escaneados e validamos o uso de imagens 3D para a mensuração de 21 distâncias lineares. Os crânios das espécies foram representados como matrizes fenotípicas (P) de covariância e de correlação entre as distâncias. A similaridade entre as P das espécies é alta. As P de todas as espécies se conformam a um padrão modular compatível com interações funcionais entre ossos. As diferenças entre as P concentram-se no rostro e são associadas a diferenças no clima entre as espécies. Detectamos sinal de seleção natural nos nós mais basais da filogenia e variação local no crânio está associada à variação na sazonalidade da chuva entre as espécies. Restrições evolutivas atuaram na diversificação do crânio das espécies, defletindo as respostas evolutivas para tamanho. Concluímos que tanto seleção estabilizadora e direcional, conectadas à variação climática, quanto restrições evolutivas atuaram na diversificação do crânio das espécies / Concepts and methods within the theories of morphological integration and quantitative genetics characterize the foundation to study the evolution of complex structures, composed of several traits that interact with each other. In this work, we used the skull as a model of complex structure and we studied its diversification in toad species belonging to the Rhinella granulosa group. The questions addressed were: (1) Is the (co)variance structure similar across species?; (2) Is the (co)variance structure modular in the species, and compatible with developmental or functional interactions among traits?; (3) Do external factors, such as phylogeny and climate, structure the similarity in covariance pattern across species?; (4) Was the diversification of skull mean morphology driven by drift or natural selection?; (5) Is skull divergence associated to climatic variation across species?; and finally, (6) Is there a role for evolutionary constraints in species skull divergence? We scanned all specimens and we validated the use of 3D images to measure 21 linear distances. The skull was represented as covariance and correlation phenotypic matrices (P) among distances. P similarity is very high among species. All species\' P had a modular pattern compatible with functional interactions among bones. Differences in P were concentrated in the snout and associated to differences in climate across species. We detected a selection signal in the three most basal nodes of the phylogeny and local variation in the skull is explained by between-species variation in precipitation seasonality. Evolutionary constraints played a major role in species skull diversification, biasing evolutionary responses towards the direction of size. We conclude that stabilizing and directional selection, connected to climatic variation, as well as evolutionary constraints, acted in species skull diversification

A modularidade é uma propriedade característica que sistemas biológicos exibem em relação à distribuição de interações entre seus elementos constituintes; neste contexto, um módulo é um subconjunto de elementos que interagem entre si mais do que com outros subconjuntos. Em relação aos sistemas morfológicos, tais propriedades referem-se geralmente à estrutura do componente linear do mapa genótipo/fenótipo; no entanto, as interações genéticas, ontogenéticas e funcionais que produzem fenótipos são descritas de forma adequada através de dinâmicas não-lineares, e uma apreciação completa da complexidade destas interações é necessária para a compreensão das propriedades variacionais do fenótipo. Ademais, dados avanços metodológicos na área da morfometria, é possível escolher diferentes maneiras de representar a variação morfológica, e as diferenças entre as representações podem impactar inferências feitas sobre estas propriedades variacionais. A presente tese tem como objetivo explorar a relação entre representações morfométricas e a caracterização das propriedades variacionais, focada na análise comparativa de tais propriedades em uma escala macroevolutiva; Primatas Antropóides são utilizados como modelo, dada a disponibilidade de uma grande base de dados de mensurações cranianas destes organismo. Esta relação foi avaliada sob três perspectivas diferentes. Em primeiro lugar, estima-se taxas de erro associadas aos testes de hipótese que descrevem padrões de modularidade, relacionadas com três representações morfométricas distintas; tal avaliação é também associada à exploração de um subconjunto da base de dados utilizada aqui, levando-se em consideração a dinâmica de interações ontogenéticas que produzem o crânio dos Antropóides. Os resultados deste capítulo implicam que uma dessas representações, resíduos de Procrustes, não são capazes de detectar padrões de modularidade neste contexto, considerando suas propriedades matemáticas específicas. Outras duas representações, distâncias entre marcos anatômicos e variáveis locais de forma, produzem resultados semelhantes, que estão diretamente associados à dinâmica de desenvolvimento, e as diferenças que elas apresentam são consistentes com suas diferenças principais; taxas de erro para os testes sobre as duas representações também são aceitáveis. O próximo capítulo trata da comparação entre estas duas representações no que diz respeito a estas diferentes propriedades, focado em estimar relações alométricas associadas às variáveis locais de forma e a relação entre estas estimativas e os padrões de modularidade estimados para distâncias entre marcos anatômicos. Os resultados encontrados enfatizam que os padrões de modularidade observados em distâncias entre marcos são consequência da alometria; linhagens como Homo e Gorilla, que apresentam padrões distintos de modularidade para as distâncias entre marcos estão associados a mudanças substanciais nas relações alométricas dos caracteres cranianos. O último capítulo explora a estrutura filogenética de mudanças nas propriedades variacionais fenotípicas na diversificação de Anthropoidea, considerando apenas variáveis de forma locais, uma vez que este capítulo também visa reforçar os resultados anteriores obtidos a partir de distâncias entre marcos, considerando-se um tipo diferente de representação morfométrica. Este capítulo muda o foco de testes a respeito de padrões de modularidade definidos a priori em direção a estimar a incerteza relacionada à estrutura de matrizes de covariância, decomposta sobre a filogenia de Anthropoidea. Os resultados obtidos demonstram que as mudanças na estrutura de covariância nesta linhagem são localizadas nas mesmas regiões do crânio ao longo de toda a história evolutiva do grupo, enquanto outras regiões mantêm associações estáveis. Assim, quando se considera as diferentes propriedades de representações morfométricas cuidadosamente, inferências feitas a partir de tais representações sobre propriedades variacionais são de fato compatíveis / Modularity is a characteristic property biological systems exhibit regarding the distribution of interactions between their composing elements; in this context, a module is a subset of elements which interact more among themselves than with other subsets. Regarding morphological systems, such property usually refers to the structure of the linear component of the genotype/phenotype map; however, the genetic, developmental, and functional interactions that produce phenotypes are often best described by non-linear dynamics, and a full appreciation of the complexity of such interactions is necessary for understanding phenotypic variational properties. Furthermore, given methodological advances in the field of morphometrics, one may choose different ways to represent morphological variation, and differences between representations may impact inferences made regarding variational properties. The present dissertation aims at exploring the relationship between morphometric representations and the characterization of variational properties, focusing on the comparative analysis of such properties on a macroevolutionary timeframe; Anthropoid Primates are used as a model lineage, given the availability of a large database of skull measurements. This relationship was evaluated under three different perspectives. First, an estimation of the error rates associated with tests for hypothesis that describe modularity patterns related to three different morphometric representations; such evaluation is also associated with an exploration of a subset of the database used here, considering the dynamical properties of developmental interactions that produce the Anthropoid skull. The results of this chapter imply that one of such representations, Procrustes residuals, fails to capture modularity patterns in this setting, considering its particular mathematical underpinnings. Other two representations, interlandmark distances and local shape variables, produce similar results which are directly associated with developmental dynamics, and the differences they exhibit are consistent with their different properties; error rates for tests over both representations are also acceptable. The next chapter deals with comparing these two representations with respect to these different properties, focusing on estimating allometric relationships over local shape variables and the relationship between such estimates and modularity patterns estimated for interlandmark distances. The results found stress out that modularity patterns observed in interlandmark distances are a consequence of allometry; lineages such as Homo and Gorilla, which exhibit distinct modularity patterns in interlandmark distances are associated with substantial changes in allometric relationships for skull traits. The last chapter explores the phylogenetic structure of changes in phenotypic variational properties across Anthropoid diversification, considering local shape variables alone, since this chapter also aims at reinforcing previous results obtained from interlandmark distances, considering a different type of morphometric representation. This chapter shifts the focus from testing a priori-defined modularity patterns to estimating the uncertainty related to covariance matrix structure decomposed over the Anthropoid phylogeny. The results obtained demonstrate that changes in covariance structure on this lineage are localized in the same skull regions across the entire evolutionary history of Anthropoidea, while other regions maintain stable associations. Thus, when one considers the different properties of morphometric representations carefully, inferences made from such representations regarding variational properties are in fact compatible

Cette thèse porte sur l'anatomie et la morphologie du complexe crânien chez les murinés. Ses objectifs sont de démontrer et de décrire le lien morpho-fonctionnel entre le crâne et la force de morsure, représentant la performance, d'identifier les sources génétiques de la variation de la performance et de la morphologie, et de comprendre comment la variation morpho-fonctionnelle dépend du mode de vie d'une espèce.La première partie décrit l'anatomie de l'appareil masticateur dans le genre Mus. Des différences fonctionnelles et liées au régime alimentaire sont montrées. Puis, on s'intéresse au lien entre morphologie et fonction, et aux proxies morpho-anatomiques permettant d'estimer la force de morsure. Un modèle biomécanique des muscles masticateurs est d'abord utilisé. Les estimations obtenues sontproches des mesures in vivo au niveau interspécifique, mais moins précises au niveau intraspécifique.L'avantage mécanique et la forme de la mandibule sont ensuite utilisés comme proxies. La force de morsure estimée et réelle sont corrélées au niveau interspécifique, mais moins au niveau intraspécifique, avec des différences selon les espèces. Pour expliquer ces imprécisions, la variation ontogénétique de la force de morsure et de la forme de la mandibule sont décrites. Lorsque l'âge est contrôlé, le développement osseux ralentit plus tôt que celui de la force de morsure, ce qui peut expliquer les biais trouvés dans les estimations de la force de morsure.La deuxième partie se concentre sur les sources génétiques des variations morpho-fonctionnelles. Chez Mus minutoides, des changements sur les chromosomes sexuels produisent des différences de taille et de force de morsure. Les mâles féminisés de cette espèces sont plus agressifs que les autres individus, et montrent une force de morsure plus puissante, principalement grâce à unplus gros crâne. Le(s) gène(s) féminisant produis(ent) donc des changements à l'échelle de l'organisme tout entier. La section suivante s'intéresse aux liens entre consanguinité, asymétrie et performance chez la souris domestique. Les souris les plus consanguines ne montrent pas d'augmentation de l'asymétrie de leurs mandibules, et la performance des souris les plus consanguines ou les plus asymétriques n'est pas affectée. Enfin, l'héritabilité de la force de morsure et de la morphologie est estimée. La force de morsure in vivo n'est pas héritable, bien que la morphologie le soit. Etant donné le lien entre morpho-anatomie et force de morsure, ces résultats suggèrent que les changements morphologiques sont des voies de moindre résistance évolutive, et qu'ils peuvent être à l'origine de changements de performance.La dernière partie utilise la morphologie et la performance en tant que caractères liés à l'écologie des espèces. La première section s'intéresse aux différences de performance entre Apodemus sylvaticus et Mus spretus, qui partagent leur habitat et leurs ressources alimentaires, malgré une différence de taille marquée. Nos résultats montrent un recouvrement des distributions des forces de morsures, soutenant l'hypothèse d'un régime alimentaire commun. Cette coexistence pourrait être due à une abondance de ressources là où ces espèces sont syntopiques. Enfin, la variation morphologique est quantifiée chez plusieurs murinés d'Asie du Sud-Est. Les espèces de rats commensaux et généralistes sont moins variables que les autres espèces. Les espèces synanthropiques montrent des réponses morpho-fonctionnelles convergentes entre localités qui suggèrent qu'elles partagent des patrons communs de réponse et donc qu’elles peuvent s'adapter aux variations environnementales régionales induites par l’homme. L'approche utilisée dans cette thèse nous a permis de montrer le lien entre variation génétique,phénotypique et écologique. Ce lien parfois difficile à décrire, est cependant à la base de l'apparition de nouvelles formes et espèces, et constitue un aspect crucial de la biologie de l'évolution. / The theme of this thesis is the anatomy and morphology of the cranio-mandibular complexin various species of murine rodents. The main objectives are to describe the morpho-functional link between the skull and bite force as a measure of performance, to identify the genetic sources of morphological and performance variation, and finally to understand how morpho-functional variation depends on a species diet and lifestyle. The first part describes the anatomy of the masticatory apparatus in the genus Mus. Differences were found, which could be interpreted functionally and linked to variation in diets. The first part also investigates the links between morpho-anatomy and function, and various morphological proxies used for estimating bite force. This is done by building a biomechanical model of masticatory muscles. The bite force estimates obtained match the in vivo measurements at the inter-specific level, but are less precise at the intra-specific level. Then, two osseous mandibular proxies of bite force are compared (lever arms and their mechanical advantage, and its shape data). In vivo and estimated bite force werewell related at the inter-specific level, but less at the intra-specific level, depending on the species. To explain these imprecisions, the ontogenetic variation of bite force and mandibular morphology isdescribed. Under controlled age, the bony development is slowing down earlier than bite force, whichcan partly explain the inconsistencies of estimated bite force.The second part focuses on the genetics of morphological and functional variation. In Musminutoides, changes in the sexual chromosomes entail size and performance changes. The feminized males found in this species are known to be more aggressive than other individuals, and they produce ahigher bite force, mainly due to an increase in skull size. The feminizing gene(s) therefore drive whole-organism-scale changes. Then, the links between inbreeding, asymmetry and performance areinvestigated in the house mouse. The most inbred mice do not experience an increase in the asymmetry of their mandibles. Contrary to expectations, the performance of the most inbred or most asymmetric mice do not decrease and differences in asymmetry levels have no influence on biting performance.The last section estimates the heritabilities of bite force and morphology. In vivo bite force is notheritable, but some morphological characters are. Given the functional link between morpho-anatomyand bite force shown in the first part, these results suggest that morphological changes represente volutionary pathways of least resistance, and drive changes in performance rather than behavioral or related traits.The last part took morphology and performance as linked to a species' niche. The first sectionexplores the differences between Apodemus sylvaticus and Mus spretus. Both share their habitat and food resources, in spite of a marked size difference. Results show great overlap between their bite force distributions supporting the hypothesis of a shared diet. The absence of shift in a trait related toresource use may be due to a large abundance of the food resources where both species are found insyntopy. In the final section the morphological variation in several rodents from Southeast Asia wasquantified. Less morphological variability is found in generalist and commensal rats by comparison toother species. At the community level, synanthropic species show frequent convergent responsesbetween localities in terms of bite force and morphology. These common patterns in response suggestthat synanthropic species tend to be very adaptable to regional environmental differences.The approaches used in this thesis enable us to show the link between genetic, phenotypic andecological variation. This link, sometimes difficult to describe, is nevertheless at the root of theappearance of new forms and species, and constitutes a crucial aspect of evolutionary biology.

Animal personality is found in a wide range of taxa, yet our knowledge of what maintains consistent among-individual variation in behaviour is still incomplete. Many personality traits are associated with fitness, leading to the expectation that, under selection, genetic (and among-individual) variation will be eroded over time. Several adaptive models have been developed in order to explain this maintenance of variation. These include state-dependence, state-behaviour feedback loops, life-history and behavioural coadaptation and the Pace of Life syndrome. These models represent good starting points for thinking about what drives and maintains among-individual variation in behaviour, and while empirical support for these models is mixed, one thing they do have in common is the assumption of a significant genetic basis underpinning personality traits. Significant heritability is required for an evolutionary response to selection and for among-individual variation to be adaptive. The univariate estimates of heritability for personality traits that are growing in the literature, while useful, are likely insufficient to predict how personality traits will respond to selection. This thesis uses the Trinidadian guppy, Poecilia reticulata, and other species to explore patterns of among-individual and genetic variation in personality traits, advocating the benefits of using multivariate perspectives throughout. Firstly, the among-individual covariance structure between measures of boldness, growth and metabolic rate are estimated in a test of the Pace of Life syndrome. Secondly, an appraisal of the relative strength of maternal and genetic effects on offspring personality and how it changes over ontogeny. Next, a comprehensive treatment of sexual dimorphism in behaviour and size followed by analysis of genotype-by-sex interactions using both univariate and multivariate methods. Finally, a comparative analysis of personality in 7 species of small fish, identifying the main axis of among-individual variation from a single assay in each and quantifying the phylogenetic signal.

Le potentiel évolutif des populations naturelles à répondre aux changements environnementaux détermine leur capacité à s'adapter et à survivre. Pour achever une évolution adaptative, la fitness doit être héritable, i.e. doit être transmise des parents à leurs descendants par des gènes. Pour pouvoir mesurer le potentiel évolutif d'une population en milieu naturel, il est primordial d'avoir au préalable des informations sur la fitness des individus qui la composent, mais aussi de connaître la fitness de leurs descendants. Les mesures de fitness sont extrêmement rares, en particulier pour les espèces marines, où les relations entre les générations sont rarement connues. Dans cette thèse, je présente le premier pedigree construit pour une population de poissons marins sur la base du suivi génétique mené depuis plus de 10 ans sur les poissons-clowns orange de l'île de Kimbe (Papouasie-Nouvelle Guinée). Le pédigrée comprend 2927 individus et révèle une philopatrie natale sur 5 générations. L'approche en génétique quantitative révèle que la fitness locale a une très faible valeur d'héritabilité (<1%). La variation génétique additive et les effets maternels sont également très faibles (<1%). En revanche, l'habitat est le principal facteur qui explique les différences de fitness locale observées entre les individus (jusqu'à 96,5%). Ensemble, ces résultats suggèrent que, bien que l'environnement impose une forte pression de sélection sur la fitness locale, la population de poissons-clowns orange a un très faible potentiel d'évolution face aux changements environnementaux. / The evolutionary potential of wild populations to respond to environmental change will determine their capacity to adapt and survive. However, in order to achieve evolutionary change, variation in the contribution of an individual to the next generation — its fitness — must have a genetic basis and be heritable. The study of the evolutionary potential of populations requires longitudinal and relatedness data with different environments to partition the contribution of genes, maternal effects and environment on fitness. Estimates of genetic heritability of fitness traits are extremely rare, especially for marine species, where inter-generational relationships are rarely known. Here, we present the first multi-generational pedigree for a marine fish population by repeatedly genotyping all individuals in a population of the orange clownfish (Amphiprion percula) at Kimbe Island (Papua New Guinea) over a 10-year period. Based on 2927 individuals, our pedigree analysis revealed that longitudinal philopatry was recurrent over five generations. We show that local reproductive success has a very low (<1%) but significant heritability. We also show that additive genetic variation and maternal effects on local fitness are both extremely low (<1%). Habitat is the major driver that explain differences in the contribution of individuals to the next generation in the local population (until 96.5%). Together these results suggest that while the environment imposes strong selection pressures on the local fitness, the low heritability indicates the orange clownfish population has little evolutionary potential to adapt to local environmental changes.

Analysing variation of skull shape in wild populations can give us an insight into evolutionary processes. By looking into patterns of morphological variation within populations, we can extrapolate and make assumptions on the patterns of variation on higher taxonomic levels. In this thesis, I collected data on skull shape of a wild population of Soay sheep using geometric morphometrics methods. I applied a multitude of quantitative genetics and geometric morphometrics methods to explore the factors behind the evolution of skull shape. I analysed several aspects of skull shape, including integration and modularity, predicted response to hypothetical selection, estimates of natural selection, presence of heterochrony, and fluctuating asymmetry (FA) in an ecological and genetic point of view. I found low levels of integration in the Soay sheep skull, along with the presence of two modules: face and neurocranium. Both the levels of integration and the pattern of modularity were found across different origins of variation, individual, genetic and developmental (FA), indicating a strong correspondence between levels. Although genetic integration is not strong, I found that most of hypothetical selection regimes result in as much correlated selection as direct selection responses. But the nose region has shown to be quite independent from the rest of the skull, with a retraction of the nose causing almost no correlated changes. Selection on skull shape is comparatively strong in the Soay sheep. The skull shape selected for in males differs from the shape selected in females. Males are selected to have wider nasal bones along with longer, flatter braincase, whereas females are selected towards narrower nasal bones, along with smaller braincases. But selection is not the only factor influencing changes in skull shape. Changes in temperature along the past 30 years are causing a change in developmental timing in Soay sheep, causing a decrease in overall body size in the population. And I found that skull shape is also being affected, thus indicating that this population might be undergoing heterochronic processes. Finally, I found that factors such as vegetation quality, parasite load and breeding success are related to FA levels, whereas population density and climate are not. I also found no significant heritability nor dominance in FA of skull shape. Overall, this thesis certainly contributes to the understanding of evolution of skull shape in natural populations. By successfully combining quantitative genetics and geometric morphometrics methods, I was able to tackle questions about the evolution of complex shapes, and give valuable insights into this still underexplored field.