Re: Human Language. (long post)

John A. Halloran (
7 Jan 1997 12:03:02 -0700

In article <> Michael McBroom <> writes:

The question is whether the larynx descended lower in the vocal tract during
human evolution for linguistic or nonlinguistic reasons. If it started to
descend for linguistic reasons, then one must date the beginnings of speech to
the time when this descent began, as changes to a stable pattern do not
normally begin without selective pressure.

What are the oldest skeletons that show evolution away from the primate vocal
tract pattern?

>> The principal question is for what reason have other species developed a vocal
>> tract that permits or enhances long-distance vocalizations. This can throw
>> light on the evolution in the human vocal tract.

>Oh really. Your principal question is germane to the issue only if we
>assume that the human vocal tract evolved due to selectional pressures
>that favored long-distance communication. There is clear evidence that
>it did not. When's the last time you've tried to carry on a
>conversation by shouting to somebody down the street? Pretty hard to
>do, huh? The hard consonants don't travel, and even the ones that do,
>don't travel that far. What you're left with are open vowels and vowels
>that are "colored" by the nasals and the retroflex [r]. One of the
>principle advantage we possess as users of a full-blown system of
>language is the ability to communicate rapidly with each other. You
>just can't do this sort of thing at a distance.

Long-distance communication need not involve forming words involving
consonants. The long-distance vocalizations of other species serve a valuable
communicative function without requiring the enunciations that you describe.

>> This does not mean that improved vowel production was not
>> important to nonlinguistic vocalizations, however. But you have not dealt
>> with the issue that descent of the larynx also aids in producing deeper,
>> lower-pitched vocalizations.

>I have stated repeatedly that non-linguistic vocalizations were not what
>our vocal tract has been selected for. I have also stated that the
>descent of the larynx was for different reasons than the specific
>production of lower-pitched vocalizations. In other words, I reject
>your claims on the basis that there is no evidence to suggest that the
>human vocal tract evolved for the uses you indicate.

If it is true that

1. low-pitched sounds travel longer distances than high-pitched sounds; and

2. a larynx lower in the throat enables creation of lower-pitched

then there is a clear alternative to the theory that the human larynx
descended for linguistic reasons.


John Halloran