Urban life shapes genetic diversity in the green anole, Anolis carolinensis.

Urbanization presents unique environmental pressures that drive rapid evolutionary adaptations, particularly in species inhabiting fragmented and anthropogenic landscapes. In this study, we investigate the genomic differentiation between urban and non-urban populations of Anolis carolinensis, focusing on two main aspects: (1) the effect of habitat fragmentation on inbreeding and mutational load (2) genomic adaptation to the urban habitat. Using genome-wide scans of selection and analyses of genetic diversity, we identify key genomic regions exhibiting significant divergence between urban and non-urban populations. These regions are enriched for genes associated with immunity, behavior, and development, suggesting that urban adaptation is polygenic and involves traits related to stress response, locomotion, and thermoregulation. By comparing candidate genes linked to urban adaptation in another Anolis species, A. cristatellus, we detect potential signatures of convergent evolution in loci involved in immune response and behavior, further supporting the hypothesis that urban environments exert similar selective pressures across species. These results provide evidence for polygenic adaptation and highlight the complexity of urban evolution. Future work with denser population sampling and time-series data will be essential to confirm the role of urban selective pressures and track the genetic dynamics of urban populations over time.