Processes driving male breeding colour and ecomorphological diversification in rainbow skinks: a phylogenetic comparative test

First published online in 2009We used a phylogenetic comparative approach to investigate the importance of ecological shifts in the diversification of both signalling traits and ecomorphological traits in a diverse group of Australian skinks (Carlia). First, we tested whether divergence in male breeding coloration is associated with shifts in habitat openness. Second, we examined whether the type or location of male breeding coloration changes predictably with habitat openness. Third, we tested the ecomorphological predictions that body size should vary in relation to habitat openness and that limb length, toe length and head depth should vary with substrate use. Divergence in male breeding coloration was positively associated with shifts in habitat openness. Our results also indicate that species occupying more open habitats tend to use male sexual signals located on lateral body regions and not necessarily on body regions that are potentially more concealed from aerial predators (e. g. chest and throat). With regard to ecomorphological traits, habitat openness appears to have no predictable influence on body size at the inter-specific level, contrary to expectations based on intra-specific studies. However, consistent with functional predictions, we found that preference for rocky habitats is associated with relatively longer hind limb length, presumably due to selection for greater speed and jumping ability on these substrates. Overall, results of this study support the hypothesis that ecological shifts play a central role in promoting morphological diversification. © Springer Science+Business Media B.V. 2009.Gaynor Dolman, Devi Stuart-Fo