Invasive species offer powerful replicated experiments into the processes that shape evolutionary change. The rapid evolution exhibited by invasive species enables direct observation of genetic and phenotypic change. Species invasions therefore enable determination of the relative contribution of deterministic and stochastic forces in promoting evolutionary change. Introductions are predicted to result in the erosion of genetic variation, restricting the ability to respond to selection and adapt to the new environment. Nonetheless, many introductions are successful. I aim to resolve this genetic paradox posed by invasive species using the delicate skink, a successful invasive reptile in the Pacific, as a model system.