Evolution of Vocal Diversity through Morphological Adaptation without Vocal Learning or Complex Neural Control

摘要: Summary The evolution of complex behavior is driven by the interplay morphological specializations and neuromuscular control mechanisms [1–3], it often difficult to tease apart their respective contributions. Avian vocal learning associated neural adaptations are thought have played a major role in bird diversification [4–8], whereas functional significance substantial diversity the organ remains largely unexplored. Within most species-rich order, Passeriformes, "tracheophones" suboscine group that, unlike oscine sister taxon, does not exhibit [9] phonate with tracheal membranes [10, 11] instead two independent sources found other passerines [12–14]. Here we show tracheophones possess three sound sources, oscine-like labial pairs unique membranes, which collectively represent largest described number for organ. Birds experimentally disabled were still able phonate. Instead main source, constitute specialization, which, through interaction bronchial labia, contributes different acoustic features such as spectral complexity, amplitude modulation, enhanced amplitude. In contrast, these same arise oscines from [15–17]. These findings supported modeling approach and provide clear example how adaptation tracheophone can generate specific, features. Morphological specialization therefore constitutes an alternative path that control.