Performance is key to survival. From day-to-day foraging events, to reproductive activities, to life-or-death crises, how well an organism performs these tasks can determine success or failure. Selection, therefore, both natural and sexual, act upon performance, and performance demands on individuals shape a population’s morphological and physiological trait distributions. While studies of morphological adaptations to ecological pressures implicitly center on the idea that responses to selection improve performance via changes in morphology, the relationships between morphology, performance, and fitness are not always well understood. In this dissertation, I investigate these relationships explicitly, as well as determine the effects that different ecological and genetic contexts have on selection and how populations respond to performance pressures. Using a model of lizard locomotor performance, I address three issues that may impact selection on performance that are often overlooked in performance studies. First, performance is not a static trait. Rather, individuals possess a range of performance abilities or intensities that can be expressed as needed. Using a novel, individual-based, quantitative genetic simulation model, I demonstrate the effects of variable performance expression and genetic constraints on how a population experiences and responds to selection on sprint and endurance performance. Second, sex differences in performance are expected in sexually dimorphic species, but empirical evidence for this is lacking. To this end, I measured and analyzed multivariate morphology and performance in Anolis carolinensis to identify sex-specific patterns in functional morphology and functional trade-offs within a broad suite of performance traits. Third, intralocus sexual conflict should constrain the evolution of the multivariate performance phenotype in both sexes. By extending the simulation model to include correlated trait inheritance between sexes and sex-specific selection on certain performance traits, I demonstrate the extent to which this sexual conflict constrains performance evolution. In combining studies of natural populations with simulation studies of selection, this dissertation embraces the complexity of performance to address the multiple contributing factors and constraints on performance evolution, and demonstrates the importance of accounting for such complexity when studying animal performance.

Submitted by Louise Schechtman (louisesche@gmail.com) on 2013-04-29T20:58:12Z No. of bitstreams: 1 Dissertação_Mestrado_Louise.pdf: 1460380 bytes, checksum: b9f0b3d16c71cf41d7b902173d83da39 (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2013-05-13T19:15:21Z (GMT) No. of bitstreams: 1 Dissertação_Mestrado_Louise.pdf: 1460380 bytes, checksum: b9f0b3d16c71cf41d7b902173d83da39 (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2013-05-15T12:40:34Z (GMT) No. of bitstreams: 1 Dissertação_Mestrado_Louise.pdf: 1460380 bytes, checksum: b9f0b3d16c71cf41d7b902173d83da39 (MD5) / Made available in DSpace on 2013-05-15T12:40:48Z (GMT). No. of bitstreams: 1 Dissertação_Mestrado_Louise.pdf: 1460380 bytes, checksum: b9f0b3d16c71cf41d7b902173d83da39 (MD5) Previous issue date: 2012-01-30 / Understanding the variability in performance among firms, to understand what leads above average performance and competitive adv antage are among the main issues in the field of strategy. The competitive advantage is a construct with difficult operation for its complex meaning that lead for many interpretations. However it is often pointed to as causing above - average performance. The variability of firm performance over time is also treated frequently, especially at firm and sector levels. However, most empirical work in the field of strategy only gives a dimension to this variability, studying it only in terms of its average. A se cond dimension, the trend of performance, was considered in this study, using multilevel models. How t he performance of a firm evolves over time allows then a different classification , in terms of competitive advantage , competitive disadvantage or parity. C ompared these results with those of average performance made clear the importance of analyzing the performance of two dimensions: the average and its trend. / Compreender a variabilidade do desempenho entre as firmas e compreender o que leva a desempenhos acima da média e vantagem estão entre as principais questões no campo da estratégia empresarial. Vantagem competitiva é um construto de difícil operacionalização, por seu significado complexo, que dá margem a diferentes interpretações. Entretanto ela é apontada com freqüência como causadora de desempenho acima da média. A variabilidade do desempenho das empresas ao longo do tempo também é uma questão tratada com frequência, especialmente no que se trata dos níveis firma e setor. No entanto, a maior parte dos trabalhos empíricos no campo de estratégia dá apenas uma dimensão a essa variabilidade, estudando-a apenas em termos de média. Uma segunda dimensão, a tendência do desempenho, passa a ser considerada neste estudo, utilizado modelos multinível. Como o desempenho de uma firma evolui ao longo do tempo comporta assim, uma diferente análise, em termos de vantagem competitiva, desvantagem competitiva ou paridade. A comparação deste resultado com aqueles de desempenho médio tornou claro a importância de se analisar o desempenho em duas de suas dimensões: a média e sua tendência.