Determinants of Species Richness and Trait Diversity in Galapagos' Native Biota

摘要

The evolutionary processes involved in species and trait diversification are key to the formation of island biological diversity. The goal of my thesis is to understand how variation in habitat promotes species richness and trait diversity in the biota of the Galapagos archipelago. My first objective is to understand how the dynamics of island formation influences the number of species found on islands. Results of this work suggest that adding landscape complexity improves models of island species richness. Interestingly, landscape complexity significantly contributes to models of species richness only for a subset of taxonomic groups tested. My second objective is to quantify the association between habitat features and variation in morphology and physiology of endemic land snail species. Results indicate that using cloud cover and shell shape as proxies for climate and morphology, respectively, climate has a positive effect on physiology whereas morphology has a negative effect on physiology.