Dunn and colleagues (2008) describe and exemplify the use of sophisticated analyses of abstract structural features to reconstruct language histories. The techniques that they use do show some clustering in the groups of languages that they examine; Dunn et al. state that they ‘tend to favor a phylogenetic origin for the signal of relatedness’ (p. 748), and that the results of their test case ‘show a close degree of correspondence to the existing linguistic classification based on sound-meaning correspondences’ (p. 747). We argue that a more parsimonious explanation for the results obtained by Dunn et al.'s methodology is that it accurately maps linguistic geography, the network of contact and diffusion that postdates a proto-language, in most cases corresponding to geographic distance.