Talk:Yawn/to do


 * Improve references
 * Expand short sections and ensure good flow throughout article
 * Which animals yawn, and has it evolved independently more than once?
 * A little further explanation as to how yawning is advantageous - how would an organism that didn't yawn/respond to yawns be more likely to die?
 * Physiologically, what is the difference (if there is any) between a true reflexive yawn and a voluntary effort to simulate a yawn? Why do they feel different?
 * What medical conditions produce yawning?