Figure 3.

Summary of the transition rates with support for a model of dependent trait evolution for numeral opacity. This information summarizes graphically the same information in electronic supplementary material, figure S14, which gives relative speeds of all rates. Arrows are weighted by the transition speed, with fastest rates the heaviest. 0 denotes a compositional form, 1 an opaque one. Thus 0,0 is the state in which both numerals 3 and 4 are compositional; 0,1 is a state with compositional 3 but opaque 4 and so forth. Solid line denotes a missing state (these are languages with upper limit of three numerals, and hence no form for 4).