Morphology of Invasion: 3D cranial morphology of Florida's Nile monitor population

The invasion of the Nile monitor ( Varanus niloticus ) into Florida provides an opportunity to examine the morphological response of an important predator to a new environment. This study quantifies cranial morphological differences between the wild African population and the invasive Florida population of Varanus niloticus in an effort to understand the effects of differential selection pressures on cranial morphology. Three‐dimensional landmark data were collected from the skulls of invasive and wild Nile monitors and comparatively analyzed using geometric morphometric techniques. Regions of morphological divergence and conservatism of invasive Nile monitor crania were identified and quantified. Invasive animals exhibit significant lateral compression of the rostrum, narrowing of the skull, reduced muscular volume, as well as other differences. The basis for the dysmorphology in invasive animals may be attributable to multiple evolutionary and non‐evolutionary factors (e.g., ontogenetic, nutritional, biomechanical), all owing to the local ecology. The combination of morphological and ecological analyses of this invasive species presents a unique opportunity to examine a species undergoing rapid evolutionary change in a novel environment.