A common creationist conception is that at creation humanity (and perhaps all newly-created species) were "genetically perfect".
I have no idea what "genetically perfect" means.
But a recent discussion on the evolution of language gave me this thought.
One of the prerequisites for human language is a precise positioning of the pharynx.
In most mammals, including the other great apes, the pharynx is placed high up in the throat, above the opening of the esophagus.
Even human infants are born with the pharynx in the high position. This enables them to breathe while breastfeeding. They can breathe and swallow at the same time.
During the first year of life, however, the human pharynx moves from this position to a position lower in the throat. This frees up the back of the tongue, allowing it to be more flexible. This is an essential condition for the development of human speech, especially for pronouncing the back consonants (k, g, , ng, the back "l" of "ball" the Scottish "ch" etc.) and the back vowels "oh" and "ooo" where the tongue is raised at the back of the mouth. Irrespective of mental capacity, the basic physical reason other apes do not speak like humans is that their higher pharynx blocks these movements of the tongue.
So a dropped pharynx is clearly one of the traits indicative of the human species and one we certainly prize as essential to human communication.
A possible sign of "genetic perfection"?
But wait. The dropped pharynx is dangerously close to the opening of the esophagus and the reason we are prone to get food "going down the wrong way".
Animals with a higher pharynx don't choke on their food. But this is a common danger for humans, and not infrequently fatal. IOW the same genetic innovation that gave us our capacity for speech also introduces a sometimes fatal imperfection. What sort of "genetic perfection" calls for this sort of trade-off?
I have no idea what "genetically perfect" means.
But a recent discussion on the evolution of language gave me this thought.
One of the prerequisites for human language is a precise positioning of the pharynx.
In most mammals, including the other great apes, the pharynx is placed high up in the throat, above the opening of the esophagus.
Even human infants are born with the pharynx in the high position. This enables them to breathe while breastfeeding. They can breathe and swallow at the same time.
During the first year of life, however, the human pharynx moves from this position to a position lower in the throat. This frees up the back of the tongue, allowing it to be more flexible. This is an essential condition for the development of human speech, especially for pronouncing the back consonants (k, g, , ng, the back "l" of "ball" the Scottish "ch" etc.) and the back vowels "oh" and "ooo" where the tongue is raised at the back of the mouth. Irrespective of mental capacity, the basic physical reason other apes do not speak like humans is that their higher pharynx blocks these movements of the tongue.
So a dropped pharynx is clearly one of the traits indicative of the human species and one we certainly prize as essential to human communication.
A possible sign of "genetic perfection"?
But wait. The dropped pharynx is dangerously close to the opening of the esophagus and the reason we are prone to get food "going down the wrong way".
Animals with a higher pharynx don't choke on their food. But this is a common danger for humans, and not infrequently fatal. IOW the same genetic innovation that gave us our capacity for speech also introduces a sometimes fatal imperfection. What sort of "genetic perfection" calls for this sort of trade-off?
