The topography of the Upper Yupno valley surrounding the village of Gua. (A) Shows the approximate directions of the source and mouth of the Yupno river. (B) Shows a detail of the Gua area with mean pointing directions for past- and future-category gestures produced outdoors, including 95% confidence cones (based on 1000 parametric bootstrap estimates). The past points downhill through the elevation lines towards the mouth of the rive