By chance, these changes gave us greater aptitude for speech but also the danger of “tracheal obstruction,” in the words of Daniel Lieberman. The problem is that, we send our air and food down the same tunnel. Only a small structure called the epiglottis, a kind of trapdoor for the throat, stands between us and catastrophe. The epiglottis opens when we breathe and closes when we swallow, sending food in one direction and air in another, but occasionally it errs and the results are sometimes dire.
