At what point in evolutionary history did the pharynx join up with the larynx.?

Question

And what were the evolutionary advantages and disadvantages of this occurrence?

I'm pretty sure that some mammals (maybe most?) have no connection between the pharynx and the larynx. I think man is somewhat unique but I don't know how unique.

I think I formulated this question incorrectly and threw everyone off base. I should have asked, "At what point in mammalian evolution did the larynx descend lower in the trachea so it could no longer shut off the nasal passage during swallowing of food, thereby increasing the risk of choking?" Quite a different question you see. I apologise for not being clearer initially.

For what Wikipedia has to say on this matter see

http://en.wikipedia.org/wiki/Larynx#Descended_larynx

Answer 1

I believe it was somewhere after the loss of the cleithrum, so maybe early sarcopterygian tetrapods?

Answer 2

The same factors that favored the evolution of air-breathing animals on earth led to the evolution of the larynx. Thus, along with the first air-breathing animals, there appeared a primitive sort of larynx.
I guess that would take us back to the point of evolution where the first water animals moved from the sea to land about 315 million years ago.


The larynx is critical for human speech and singing. The advantages and disadvantages here depend on who is singing :-) and how well they sing :-)

The larynx is important for swallowing, coughing, vomiting and eliminating contents of the abdomen.
Again here, the advantage of swallowing allows us to be alive....disadvantage....it can make us fat :-)

Answer 3

Once the head and neck have been separated into left and right halves, you can see relationships of the nasal cavity, oral cavity and larynx to the pharynx .

When I was in dental school, I used these flash cars to memories the cavity that splits the upper respiratory cavity.

It was a lot of fun...Funny how it all comes back to you


I am sorry you are being yelled at you L......

Answer 4

Loved g3n1spiri...'s answer.


P.S. All is well that is yet to evolve - So Spoke My keyboard Larynx. :-)

Answer 5

I don't subscribe to the theory of evolution.