It is understood that our ancestors gained a strong evolutionary selective advantage in shaping the vocal tract that allowing them speak more intelligibly. However, humans pay heavy prices for the uniqueness of vocal tracts configuration. We precariously swallow our mouthful in exchange for speaking clearly, and the second heavy price humans pay is sleep snoring. Their evolutionary cause is that the respiratory system deriving on the wrong side and too late from the alimentary system. The fact that our nasal septum is usually curved contributes to these disorders. The reason of this is that a few million years ago humans had to compromise from the width of the birth canal with their pelvis in order to stand upright. As for our children’s ears, their development resembles the evolution of hominoids and they are far from smooth.

One of the traits that make modern humans unique is chin; this protrusion of the mandible is not seen in any other hominid species. There are numerous reasons for this evolutionary leap such as bipedalism, speech, development of tools and pottery, use of fire and cooking, and agricultural revolution. As for our teeth, they are still having trouble to match with our jaw which is still forming. Dentist interventions are the most recent addition to these factors, which have resulted in the continuous shrinking of our teeth and negated selection pressures; one could say that the evolutionary pressures on our jaw, chin, and teeth are no longer at work.