Fig. 1

CHD9 protein and simplified mammalian phylogeny showing the four homoplasious amino acid substitutions. a) Schematic of the CHD9 protein showing functional domains and location of the four identified homoplasious amino acids. b) Simplified mammalian phylogeny showing distribution of each amino acid corresponding to coloured circles in (a). Each amino acid shows different distributions throughout the tree and none were specifically shared between the thylacine and canids (bold text). The Ala2384 homoplasious amino acid identified in the DNA-binding domain (3) is the ancestral vertebrate residue and is highlighted in yellow. c) The Ala2384 homoplasious substitution was predicted to be a benign mutation (score of 0.053; sensitivity: 0.94; specificity: 0.84), predicted by PolyPhen-2 [31]