The physical adaptation source

Instead of looking at types of sounds as the source of human speech, we can look at the types of physical features humans possess, especially those that are distinct from other creatures, which may have been able to support speech production. We can start with the observation that, at some early stage, our ancestors made a very significant transition to an upright posture, with bipedal (on two feet) locomotion, and a revised role for the front limbs. Some effects of this type of change can be seen in physical differences between the skull of a gorilla and that of a Neanderthal man from around 60,000 years ago. The reconstructed vocal tract of a Neanderthal suggests that some consonant-like sound distinctions would have been possible. We have to wait until about 35,000 years ago for features in reconstructions of fossilized skeletal structures that begin to resemble those of modern humans. In the study of evolutionary development, there are certain physical features, best thought of as partial adaptations, which appear to be relevant for speech. They are streamlined versions of features found in other primates. By themselves, such features would not necessarily lead to speech production, but they are good clues that a creature possessing such features probably has the capacity for speech.

Teeth, lips, mouth, larynx and pharynx

Human teeth are upright, not slanting outwards like those of apes, and they are roughly even in height. Such characteristics are not very useful for ripping or tearing food and seem better adapted for grinding and chewing. They are also very helpful in making sounds such as f or v. Human lips have much more intricate muscle interlacing than is found in other primates and their resulting flexibility certainly helps in making sounds like p or b. The human mouth is relatively small compared to other primates, can be opened and closed rapidly, and contains a smaller, thicker and more muscular tongue which can be used to shape a wide variety of sounds inside the oral cavity. In addition, unlike other primates, humans can close off the airway through the nose to create more air pressure in the mouth. The overall effect of these small differences taken together is a face with more intricate muscle interlacing in the lips and mouth, capable of a wider range of shapes and a more rapid and powerful delivery of sounds produced through these different shapes.

The human larynx or “voice box” (containing the vocal folds or vocal cords) differs significantly in position from the larynx of other primates such as monkeys. In the course of human physical development, the assumption of an upright posture moved the head more directly above the spinal column and the larynx dropped to a lower position. This created a longer cavity called the pharynx, above the vocal folds, which acts as a resonator for increased range and clarity of the sounds produced via the larynx and the vocal tract. One unfortunate consequence of this development is that the lower position of the human larynx makes it much more possible for the human to choke on pieces of food. Monkeys may not be able to use their larynx to produce speech sounds, but they do not suffer from the problem of getting food stuck in their windpipe. In evolutionary terms, there must have been a big advantage in getting this extra vocal power (i.e. a larger range of sound distinctions) to outweigh the potential disadvantage from an increased risk of choking to death.

The tool-making source

In the physical adaptation view, one function (producing speech sounds) must have been superimposed on existing anatomical features (teeth, lips) previously used for other purposes (chewing, sucking). A similar development is believed to have taken place with human hands and some believe that manual gestures may have been a precursor of language. By about two million years ago, there is evidence that humans had developed preferential right-handedness and had become capable of making stone tools. Wood tools and composite tools eventually followed. Tool-making, or the outcome of manipulating objects and changing them using both hands, is evidence of a brain at work. The human brain is not only large relative to human body size, it is also lateralized, that is, it has specialized functions in each of the two hemispheres. Those functions that control the motor movements involved in complex vocalization (speaking) and object manipulation (making or using tools) are very close to each other in the left hemisphere of the brain. It may be that there was an evolutionary connection between the language-using and tool-using abilities of humans and that both were involved in the development of the speaking brain. Most of the other speculative proposals concerning the origins of speech seem to be based on a picture of humans producing single noises to indicate objects in their environment. This activity may indeed have been a crucial stage in the development of language, but what it lacks is any structural organization. All languages, including sign language, require the organizing and combining of sounds or signs in specific arrangements. We seem to have developed a part of our brain that specializes in making these arrangements. If we think in terms of the most basic process involved in primitive tool-making, it is not enough to be able to grasp one rock (make one sound); the human must also be able to bring another rock (other sounds) into proper contact with the first in order to develop a tool. In terms of language structure, the human may have first developed a naming ability by producing a specific and consistent noise (e.g. bEEr) for a specific object. The crucial additional step was to bring another specific noise (e.g. gOOd) into combination with the first to build a complex message (bEEr gOOd). Several thousand years of development later, humans have honed this message-building capacity to a point where, on Saturdays, watching a football game, they can drink a sustaining beverage and proclaim This beer is good. As far as we know, other primates are not doing this.

The genetic source

We can think of the human baby in its first few years as a living example of some of these physical changes taking place. At birth, the baby’s brain is only a quarter of its eventual weight and the larynx is much higher in the throat, allowing babies, like chimpanzees, to breathe and drink at the same time. In a relatively short period of time, the larynx descends, the brain develops, the child assumes an upright posture and starts walking and talking. This almost automatic set of developments and the complexity of the young child’s language have led some scholars to look for something more powerful than small physical adaptations of the species over time as the source of language. Even children who are born deaf (and do not develop speech) become fluent sign language users, given appropriate circumstances, very early in life. This seems to indicate that human offspring are born with a special capacity for language. It is innate, no other creature seems to have it, and it isn’t tied to a specific variety of language. Is it possible that this language capacity is genetically hard-wired in the newborn human? As a solution to the puzzle of the origins of language, this innateness hypothesis would seem to point to something in human genetics, possibly a crucial mutation, as the source. This would not have been a gradual change, but something that happened rather quickly. We are not sure when this proposed genetic change might have taken place or how it might relate to the physical adaptations described earlier. However, as we consider this hypothesis, we find our speculations about the origins of language moving away from fossil evidence or the physical source of basic human sounds toward analogies with how computers work (e.g. being pre-programmed or hard-wired) and concepts taken from the study of genetics. The investigation of the origins of language then turns into a search for the special “language gene” that only humans possess.

(from The study of the language by George Yule)

Answer the questions:

1. Why is it difficult to agree with Psammetichus that Phrygian must have been the original human language?

2. What is the basic idea behind the “bow-wow” theory of language origin?

3. Why are interjections such as Ouch considered to be unlikely sources of human speech sounds?

4. Where is the pharynx and how did it become an important part of human sound production?

5. Why do you think that young deaf children who become fluent in sign language would be cited in support of the innateness hypothesis?

Match the words with their definitions:

1. brain 2. vocal folds (or cords) 3. pharynx 4. larynx 5. onomatopoeia (onomatopoeic) 6. tongue 7. speech 8. language

a. a system of communication consisting of sounds, words, and grammar, or the system of communication used by people in a particular country or type of work; b. the ability to talk, the activity of talking, or a piece of spoken language; c. the large, soft piece of flesh in the mouth that you can move, and is used for tasting, speaking, etc.; d. words containing sounds similar to the noises they describe (e.g. bang, cuckoo); e. the part of the throat that contains the vocal folds, also called the voice box; f. the area inside the throat above the larynx; g. thin strips of muscle in the larynx which can be open, in voiceless sounds, or close together, creating vibration in voiced sounds; h. the organ inside the head that controls thought, memory, feelings, and activity.