ARTS1691 - Origin and Evolution of Language

This is currently the biggest linguistic/cognitive science debate; how did language emerge, was it gradually or a big genetic mutational leap? We can read about this in the Journal: “Behavioural & Brain Sciences”
Hauser, Chomski & Fitch (2002)

However focusing on this from purely an accepted evolutionary perspective we have the following.

Necessary Evolutionary Developments

To develop language past the animal stage of grunts and gestures we require two things:

  • A brain large enough and skilled enough to develop syntax
    • The modern human brain is 2-3 times bigger than the largest Ape!Brain
    • Growth of brain and cognitive development go hand in hand, as increased brain power lends itself to use.
  • Vocal organs to enable us to produce the speech sounds necessary
    • As we have seen currently with sign language and parrot mimickers, this is not essential for language nowadays. It was however vital at the time, with the whole reason for language development depended on organised communication at night and across long distances.

External Change to Produce the Above

The 'Big Dry' ~4,000,000 years ago caused plant life to die out, leaving the hominid Australopithecus of the time to:
a) Leave the trees and make the savannah home instead
b) Find a different source of food, in the form of mammoths and other large animals.

Hunting big game requires co-ordination beyond simple grunts and gestures. We need:

  • Conditional statements; if this then this
  • A way of expressing time; we'll do this tomorrow night
  • Numbers; three game coming this way!
  • Grammatical Relationships; you kill the mammoth, I'll protect the women
  • The ability to communicate rapidly and clearly in the midst of action; RUN!

To achieve all of the above requires vocal chords for out-of-sight communication and to ensure the message was heard.

We claim hunting game was the reason for language development, as whilst tool development and cooking requires language, it does not require more than the rudimentary level attained by chimps.

Causes of Brain Development

Meat eating caused initial brain growth, and as brain growth, cognitive development and vocal organs are all symbiotically linked this led to the development of language.

Other Evolutionary Changes

Bipedalism (and general upstanding behaviour) was a result of the need for extended vision across the savannah and use of two hands for hunting/gathering. This in turn caused the vocal organs to develop in their current shape with the level of agility for the phonemes we need to communicate.

The vocal organs are built on top of the more basic breathing/eating organs, which is why infants don't develop speech sounds for a year or so.

The other key evolutionary development is the enlargement of the hole in thoracic vertebrae through which the spinal chord passes. This development enabled sustained breathing to occur, allowing syntax to become feasible.