The Great Leap Forward: the anatomic basis for the acquisition of speech and obstructive sleep apnea.

Obstructive sleep apnea is an anatomic illness caused by evolutionary changes in the human upper respiratory tract. These changes include shortening of the maxillary, ethmoid, palatal and mandibular bones, acute oral cavity-skull base angulation, pharyngeal collapse with anterior migration of the foramen magnum, posterior migration of the tongue into the pharynx, descent of the larynx and shortening of the soft palate with loss of the epiglottic-soft palate lock-up. While it is commonly believed that some of these changes had positive selection pressures for bipedalism, binocular vision and locomotion, development of voice, speech and language ultimately became a substantial contributing factor. Here it is shown that these changes are the anatomic basis of obstructive sleep apnea.