Analysis of the influence of ecological and evolutionary factors on morphological diversification of South American Xenodontinae snakes (Serpentes, Dipsadidae)

Abstract

One of the central aims of evolutionary biology is to understand the causes of morphological diversification on evolutionary radiations. The diversification process occurs simultaneously in three dimensions: genealogical, phenotypic and ecological.The investigation of variation on each of these dimensions, added to the study of the associations between the three dimensions, helps in understanding how and which processes generate biological diversity. In order to study the nature of these interactions as well as the processes that generate the morphological patterns, we will study the subfamily Xenodontinae (Serpentes, Dipsadidae). The xenodontines snakes are from South American, including about 40 genera, phylogenetically defined. They have a broad morphological diversity and wide range of ecological attributes (change in habitat and food spectrum). These features make the xenodontine a great system to study the mechanisms that promote the diversification of lineages and the processes of convergence. We intend to analyze and describe the shape of skulls, using geometric morphometric techniques; determine the association between the morphological patterns described, the molecular phylogeny of the group and the different aspects of ecology, and finally test which evolutionary processes, drift or selection, are responsible for the observed patterns.