Plot of the locations of the languages in the sample. Dark circles represent languages with ejectives, clear circles represent those without ejectives. Clusters of languages with ejectives are highlighted with white rectangles. For illustrative purposes only.
Inset: Lat-long plot of polygons exceeding 1500 m in elevation. Adapted from Figure 4 in . The six major inhabitable areas of high elevation are highlighted via ellipses: (1) North American cordillera (2) Andes (3) Southern African plateau (4) East African rift (5) Caucasus and Javakheti plateau (6) Tibetan plateau and adjacent regions.