Phylogenetic tree for Reep5 (blue labels) and Reep6 (red/black labels). Both genes are present in euteleostomes (ps12), and belong to a larger family of eukaryotic genes (ps2). The Reep6 locus in mouse codes for two proteins of different age. The older protein (Reep6) was mapped to ps2 (eukaryotes), the newer protein (Reep6 overprint) to ps17 (boreoeutherians). Note the enhanced substitution rate at the basis of this subtree (in black), as represented by branch length. Modified gene tree from Ensembl record ENSGT00550000074535.