The evolution of a word-order universal on the global language tree. In our analysis of the universal1 “With overwhelmingly greater than chance frequency, languages with normal subject–object–verb order are postpositional”, the absence or presence of the two features defines the ‘state’: state 11 (red) is the prediction made by the universal; in state 00 (black), both features are absent; in states 01 (orange) and 10 (light blue), one feature is absent and the other is present. The ancestral