Fig. 2: V2Rs have expanded in Komodo dragons and several other squamate reptiles.

a, V2R gene counts in squamate reptiles. b, Unrooted gene phylogeny of 1,024 V2R transmembrane domains across squamate reptiles. The topology of the tree supports a gene expansion ancestral to squamates (that is, clades containing representatives from all species) as well as multiple species-specific expansions through gene duplication events (that is, clades containing multiple genes from one species). Branches with bootstrap support less than 60 are collapsed. Colours correspond to species in a. Clades containing genes from a single species are collapsed.