Data from: Demographic expansion and panmixia in a St. Martin endemic, Anolis pogus, coincides with the decline of a competitor

Understanding patterns of differentiation at microgeographic scales can enhance our understanding of evolutionary dynamics and lead to the development of effective conservation strategies. In particular, high levels of landscape heterogeneity can strongly influence species abundances, genetic structure, and demographic trends. The bearded anole, Anolis pogus, is endemic to the topographically complex island of St. Martin and of conservation concern. Here, we examined genetic diversity and inbreeding, assessed which features of the landscape influence population abundances, tested for population genetic structure across St. Martin, and inferred historical demographic trends. We performed WGS on 54 individuals and conducted abundance surveys of 100 plots throughout the island of St. Martin. Genomic data are hosted elsewhere on NCBI SRA (PRJNA1278788). Hosted here are data from abundance surveys as well as metadata for individuals used to generate WGS libraries. Further, Zenodo provides scripts used to analyse the genomic and abundance data. Our data demonstrate that A. pogus is panmictic on the island of St. Martin, lacking any population structure including isolation by distance. We also find that the species has low levels of inbreeding and has likely recently experienced demographic expansion. Overall, these analyses suggest that A. pogus is unlikely to be of immediate conservation concern. Further, we highlight the role of demographic history and ecological interactions in shaping population structure.