 Adaptation, on the other hand, is highlighted in hypotheses such as the one by Edward Hagen and Gregory Bryant which posits that human music evolved from animal territorial signals, eventually becoming a method of signaling a group's social cohesion to other groups for the purposes of making beneficial multi-group alliances.The evolutionary switch to bipedalism may have influenced the origins of music.The background is that noise of locomotion and ventilation may mask critical auditory information.