RESUMO
ABSTRACT The population dynamics of a species tends to change from the core to the periphery of its distribution. Therefore, one could expect peripheral populations to be subject to a higher level of stress than more central populations (the center–periphery hypothesis) and consequently should present a higher level of fluctuating asymmetry. To test these predictions we study asymmetry in wing shape of five populations of Drosophila antonietae collected throughout the distribution of the species using fluctuating asymmetry as a proxy for developmental instability. More specifically, we addressed the following questions: (1) what types of asymmetry occur in populations of D. antonietae? (2) Does the level of fluctuating asymmetry vary among populations? (3) Does peripheral populations have a higher fluctuating asymmetry level than central populations? We used 12 anatomical landmarks to quantify patterns of asymmetry in wing shape in five populations of D. antonietae within the framework of geometric morphometrics. Net asymmetry – a composite measure of directional asymmetry + fluctuating asymmetry – varied significantly among populations. However, once net asymmetry of each population is decomposed into directional asymmetry and fluctuating asymmetry, most of the variation in asymmetry was explained by directional asymmetry alone, suggesting that populations of D. antonietae have the same magnitude of fluctuating asymmetry throughout the geographical distribution of the species. We hypothesize that larval development in rotting cladodes might play an important role in explaining our results. In addition, our study underscores the importance of understanding the interplay between the biology of a species and its geographical patterns of asymmetry.
RESUMO
Perfil Livre, uma técnica sensorial descritiva, foi utilizada na caracterização de três amostras de pudins com açúcar e cinco de pudins dietéticos comerciais. Quatorze provadores realizaram o levantamento de atributos pelo método Rede. Foram elaborados para cada provador, as listas de definições de atributos e as fichas de avaliação, empregando escala não estruturada. Utilizou-se a Análise Procrustes Generalizada para tratamento dos dados. Foram ainda determinados o perfil de textura instrumental e a cor. Foi obtida boa discriminação e os pudins foram caracterizados com base, principalmente, nos atributos cor marrom, sinérese, aroma e sabor de chocolate, sabor residual, firmeza e cremosidade. A técnica de Perfil livre mostrou-se eficiente para discriminação sensorial das amostras estudadas considerando-se atributos de aparência, sabor, odor e textura.
Free-choice profile, a descriptive sensory technique, was applied to develop the profile for three regular and five dietetic commercial chocolate puddings. Fourteen panelists were selected using triangular tests, and the Grid method was used to obtain the descriptors. Besides, individual lists, definitions of the attributes, and score sheets, where each attribute was scored on an unstructured scale, were made for the assessors. The Generalized Procrustes Analysis was applied to data. Instrumental texture profile and color were also determined. Good discrimination was observed between the samples. Puddings were mainly characterized by brown color, sineresis, chocolate aroma and flavor, aftertaste, firmness and creaminess. Free-choice profiling was efficient to discriminate studied samples considering appearance, aroma, flavor and texture attributes.