Meeting Abstract
Studying the pattern and magnitude of morphological integration and their interplay with environmental factors inducing functional specialization (e.g., diet and locomotion) are central to understanding the evolution of a complex system such as the skull. Integration in the cranial system has been studied from an ontogenetic, phylogenetic and genetic point of view, but few studies have focused on the functional demands imposed by diet and locomotion and their influence on cranial integration. Here, we aim to test the impact of function and ecology on the evolutionary covariation of the cranial system. To do so, we used marsupials as model group as they display a great diversity in diet (going from herbivory to carnivory) and locomotion (from fossorial to gliders). We used high-density geometric morphometric approaches to characterize skull shape for 70 species spanning the full phylogenetic and functional diversity in marsupials. A total of 74 landmarks and ~1,000 curve and surface sliding semi-landmarks were used to define 10 cranial regions. Each cranial region of the skull was analysed separately in order to test for a correlation between the magnitude of integration, morphological diversity, and rate of evolution. Modularity, integration and disparity analyses were performed in order to test whether a more specialized diet or type of locomotion promotes morphological integration and constrains skull shape diversity. Rates of cranial evolution were calculated for each diet and locomotor category in order to test whether the rates of evolution tend to increase or decrease depending on the degree of functional specialization.
