Fig. 3.

Nuclear phylogeny of Western Palearctic Hyla species (based on Dufresnes et al. [2018] and new analyses, supplementary fig. S1, Supplementary Material online) for which sex chromosomes have been identified (blue circles: XY system on LG1—abbreviated “1”; pink triangles: ZW system on LG4A7A—abbreviated “4A”), with possible scenarios A–C of evolutionary transitions (arrows); the focal species of this study are in bold. The phylogeny of X and Y sequences at Dmrt1 exon 1—the presumed sex-determining region of the Hyla arborea group on LG1—is adapted from Brelsford et al. (2016b).