It may be a surprise to you that of all the mammals in the world, only humans can choke and die. I'm sure there may be rare exceptions to this fact, but nearly 2800 people die every year in this country from choking. Far greater numbers of choking without dying are seen in ERs every year.
Evolutionary biologists and comparative anatomists have stated that speech and language development was ultimately detrimental to humans. It makes sense: If you have a common conduit that serves three functions (talking, swallowing, and breathing), and one overdevelops, then the other two have to suffer.
Take a look at this picture. Notice that in the chimpanzee, the voice box is behind the tongue, whereas in man, it's below the tongue. Only humans have a true space behind the tongue called the oropharynx. This is a space created behind the tongue when the epiglottis (the top part of the voice box) separated away from the soft palate. In human infants and animals, the soft palate stays overlapped with the epiglottis, allowing suckling and breathing at the same time.
This process begins at 3 months and reaches its' final position at 4 years. Adolescent boys have a second descent which lowers the voice even further. Notice also that the peak incidence of SIDS is around 2-4 months.
Furthermore, this process allows the tongue to fall back into the oropharynx, obstructing your breathing and causing frequent arousals. Terrance Davidson has a great article that I reference in my book, Sleep, Interrupted, on this topic. Here's another interesting reference on this topic from a speech development perspective.
I think the implications of these findings are enormous. What do you think? Please enter your comments below in the text box.