Mexican tetra population overview. (A) Representation of surface- and cave-morph Mexican tetra fish. (B) Phylogenetic relationships of populations used in the present study (subset from full phylogeny constructed by Moran et al. 2023). Populations belong to two distinct lineages, with cavefish evolving in each lineage. (C) Map of cave locations and surface population sampling points, San Luis Potosí and Tamaulipas, Mexico. (D) Sequencing data sets and sample sizes for each population.