standing upright meant that our heads needed to rotate downward in order to see where we were going. This reconfigured our mid and lower faces, palates, airways, and vocal chords, pushing our larynx steadily downward over the last 6 million years. Our more inferiorly positioned larynx granted us the exceptional ability to vocalize a broader range of sounds and, in association with our larger and more complex brains, helped facilitate what has become the most adept form of communication on this planet.
