The human head and the concentration of sensory devices

[sameram]

Hi, I could have posted this question in this category or in the Evolution or Zoology, but I think it has perhaps a bigger chance of getting an answer here.

So what I am looking for is to understand if there are any clear theories/explanations or evolutionary evidence on how come the:
Eyes: visual sense
Nose: olfactory
Ears: hearing
Vocal tract: food + speech

somehow all happened to evolve in a very small locality in the human body. Is this the case with all primates? or animals?
to me it seems of course trivial to see the benefits of this, but I'm trying to somehow formulate it in a scientific text to show the importance of the human face for communication from an evolutionary perspective.

Thanks a lot for any insights

[wbla3335]

It's called cephalisation (replace the "s" with a "z" if you're a Yank). An internet search should return plenty to answer your questions.

[sameram]

Thanks! lots of interesting stuff to digest on cephalisation.

so more specific questions which possibly are somewhere on the web but couldn't really manage to get answers for:

-Is there a clear reason why the vocal tract is combined with the mouth, does this offer any survival advantage of is it perhaps just a energy optimisation?

- is there a reason why the mouth happens to be in between the ears ? is it the case in all vertebrates ?(this appears to be optimal for oral communication, because by talking to the sound source i.e. the other persons mouth, we are sending the signal in the optimal direction for him to hear i.e. in between the ears).

[JackBean]

as about the second question, that's IMHO rather because mouth is only one while ears are paired and for good spatial listening, you need to have the ears on sides.