Large changes to our planet’s climate and ecosystems have presented challenges to many organisms, yet some species are apparently thriving in these new environments. One example is the Common Wall Lizard, a small, active lizard species native to mainland Europe but recently established in the United Kingdom, Canada, and the US. The research project described here seeks to identify the reasons that this species has flourished in novel urban environments on a new continent after an introduction of so few animals. Specifically, this research will leverage field observations and lab experiments including measures of behavior, physiology, and body dimensions to describe responses to new climates and altered physical habitat structure. Additionally, the research will employ new advances to identify genes related to these specific traits and how these traits have helped lizards expand across the landscape since their introduction. This information can then be leveraged in management efforts to prevent the spread of potentially harmful invasive species or to understand how organisms we want to protect may respond to changes in their environment. The infrastructure and systems established here will form the foundation of a long-term, sustainable research program for undergraduate students that will be a model for other institutions, with a specific focus on increased participation and success in STEM fields for underrepresented minorities.<br/><br/>This research program will provide an integrative understanding of the ecological context and evolutionary processes that shape the successful establishment of a vertebrate ectotherm, the Common Wall Lizard (Podarcis muralis), in a novel environment. The research will provide insight into how complex organismal phenotypes are shaped by evolutionary processes and how they respond to new ecological situations by (1) quantifying thermoregulatory behaviors and thermally-dependent traits to assess the relative influence of plasticity and adaptation in the ability of P. muralis to thrive in urban landscapes; (2) identifying morphology-performance relationships in ecologically-relevant contexts to test for morphological shifts in time and space and then assess whether these shifts contribute to invasion success and can predict future expansion; and (3) utilizing whole-genome resequencing to test hypotheses regarding the impact of the founding event on functional and neutral levels of variation at the genomic level and how this has impacted key evolutionary processes. This work leverages recent technological advances and will validate new approaches to provide resources for future studies, including the use of infrared thermography, microsensor temperature transmitters, novel application of movement modelling, and genomic sequencing technologies and analysis pipelines. This holistic approach advances our understanding of how organisms interact with novel environments and provides a conceptual basis for characterizing the phenotypic and genomic qualities that facilitate success in new or changing environments.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.