. . . e v o l u t i o n e m . . .

 

         taking a fresh look at evolution

From Savannah Apes to Modern Humans

 

This article continues with the story of our origins from basic pioneering savannah apes.

 

The above picture is a photo I took in Prague Museum of a young gorilla skeleton. It shows a surprising similarity to the human adult form - particularly with respect to cranial architecture. Adult gorillas, particularly males have a completely different form. They have distinct brow ridges and a sagittal crest for anchoring huge jaw muscles. The muzzle area is more pronounced too. The young gorilla has a larger head proportion in relation to its body. I believe that this evidence points to our origins from gorillas.

 

This phenomenon of reverting to juvenile features has been described as neoteny. I view it as another case of development truncated at a premature stage, which prevents the onset of derived features. In other words this is simply an example of reversion. Reversion can be selective; some features return to historic forms - while others are maintained in a derived state. The higher brain capacity and associated faculties could, for instance, be retained but other features like testosterone levels and some skeletal structure could revert back to ancestral levels and forms.

 

This phenomenon could have happened spontaneously when a savannah ape mother gave birth to an offspring which retained its infant skull architecture into adulthood. The result would be a form which would resemble, physically, modern man. Bang! - we now have the gene structure - with its blueprints for development to modern human forms. The proportionately large brain case (in relation to the rest of the skeleton) would have more space for new faculties and increasing bytes of  brain power.

 

The new type savannah ape would be the originator of a new gene pool of savannah apes with advantageous traits such as increased brain power over brawn. These creatures would now, perhaps, resemble more closely those described by paleo-anthropologists as Homo erectus.

 

The Elaboration of Communicating Techniques

 

By now, the early Savannah Apes will have developed a repertoire of ‘body language’ which would serve to increase communication between these individuals. There would be an instinctive recognition of postures, attitudes, and facial expressions; individuals would in effect learn to ‘read’ each other. Hand gestures would reinforce these subliminal messages. Grunts and other vocalisations would have accompanied the gestures.

 

Pointing, begging (The hand held out palm upwards), kissing, stroking, are likely to have been some of the earliest gestures.

 

Vocalisations are produced by a three stage process.

 

The first is a respiratory component, involving a variable outflow of pressurised air.

 

The second is the vibrating of vocal folds activated by the outward air flow.

 

The third is the articulatory component provided by the mouth and tongue.

 

Reptiles have only the first component which is why they hiss (like snakes) or roar (like crocodiles). Dinosaurs used to roar in this way. Basically, this is like a controlled belch; the chest contracts and forces the air out of the lungs.

 

Birds are intermediate in that some can croak in a raspy way (cranes) and others have elaborate repertoires of vocalisation - which involves using their tongues against the roof of their beaks eg. mynah birds and some parrots. Apart from these few species of birds, only mankind has come to develop all three stages of sound production to such an elaborate level. This was achieved by a lowering of the larynx in the neck and a flattening of the face - allowing the tongue to press against the inside of the front teeth. In addition the tongue became positioned slightly more forward in the mouth (relative to the other apes).

 

When you think about it, each letter sound of the alphabet represents the various ways we position our tongue, cheeks and lips in making vocalisations.

 

For A - We would hold our tongue down and slightly open our mouths. A is a lower pitch sound. E is very similar - but the tongue is held slightly wider and the mouth more closed. It is a higher pitch sound. I is produced with a wider lips position and can involve a bit of a snarl. It is also a fairly high pitch sound. O is formed by rounding the lips. U is very similar to O but involves more of a lip pucker.

 

These vowel sounds will have been the first sounds as they do not require tongue control.

 

The length of the vowel sounds can be varied dramatically whereas some of the consonants like T,(tuh) B,(buh) D,(Duh) K (Kuh) - which are formed by the tongue against the teeth - are short. These are more like impact sounds. Their length can only be increased by staccato. B and V are almost identical in sound and even today often confused with each other. M’s, made with the mouth shut can be extended as a hum like sound. This  letter sound is very easy to produce and is basically lip smacking. Stress signals would involve the simpler sound - like the high pitched eeeeeeeeee of a scream. Assuring and comfort sounds would perhaps have featured A’s and M’s - like the low pitched and slow aaaah  and mmmmm.

 

So it can be seen that these letter sounds would gradually become to be associated with certain moods and feelings and are universally significant today in our modern languages. Perhaps speech really got started when many of these letter sounds were joined in a continuous babbling utterance - as often performed by toddlers in their high chairs, eating their ice cream - ummmmaaaaammma!.

 

Studies have shown that these simple to produce letter sounds are more frequent in child babbling than the more difficult letter sounds like L and R (Locke 1983).

 

The latter sounds continue to present difficulties in later life for some speakers. Young children always find it easier to say words which have more vowels and simple letter sounds than those with less vowels and more difficult letter sounds. Often they add vowels to words to make them easier and skip over the more difficult letter sounds. For example it is easier to say ‘doggie’ than to say dog because the hard G is ridden over onto a vowel instead of coming to an abrupt halt.

 

I remember my own son saying, on anticipating the road bumps as we drove up the lane to our house, “bumnou”. It was sufficient to get the message across!

 

This often amusing way in which infants simplify the sounds of language - is consistent with Haeckel’s theory of development recapitulating evolution. This theory also applies to the descent of the larynx from the higher position in the throat of newborns to the lower position, characteristic of adults, after ten weeks.

 

The larynx is derived from the flap valve which cordons off the air tract to the lungs when an animal is ingesting food. In most mammals it allows air to be breathed in through the nasal passages at the same time food is being passed down the throat - acting as a gate.

 

It was previously understood that the larynx of mammals stayed uppermost in the throat but recent experiments using X-ray videoing on dogs showed that their larynx moves down the throat during vocalisation.

 

We can surmise that Savannah Apes gradually evolved, by selection, lower and lower larynxes - giving them more and more vocalisation abilities. The legacy of this evolution, however, is the loss of the gate mechanism; and we are now much more likely to choke on our food than our predecessors.

 

To pronounce the twenty five or so letters of the alphabet plus other double letter sounds like Th and Ch, and rapidly switch from sound to sound in quick succession, demands an astonishing amount of tongue movement.

 

The tongue is controlled by a learned motor sequencing process associated with the Broca area of the brain. As developing children, we gradually extend the speed and scope of our tongue coordination. For most of us, sentences are relatively short and well rehearsed. Basically, we have what amounts to a set response to each situation or to each question asked. These responses may be adjusted and elaborated over time but largely remain the same. Often by presenting certain key-words, a predicted response can be induced. Orators and stage actors need to rehearse their sentences ad infinitum until there is a structured string of sentences ready to flow out automatically on cue.

 

The tongue, like the hand, is an organ well served with nerve structures with direct link to the brain.

 

The basic sequencing mechanism of the tongue had evolved many hundreds of millions of years ago for the process of collecting food and water. In many ways the tongue is more manipulative than a hand. Many mammals are able to move their tongues outwards, lap up food or water, load it into the entrance of the oesophagus - and at the same time avoid the closing action of the jaws and teeth.  

 

Generally languages which have been developed by more sophisticated civilisations tend to have a wider array of letter sounds and this may be due to the blending of word sounds from a wider range of other languages. By contrast, those tribes which have been isolated as hunter gatherers until very recently - still retain a more archaic language form. Some South American indigenous people, for instance those in Paraguay, speak a language known as Guarani which is characteristically full of vowel sounds, n’s, m’s and enyas (nya). In fact to the unaccustomed ear it is difficult to determine when one word ends and another begins. The Australian aborigines also have a language profuse with these sounds. For example, here are the names of some Australian towns;

Wallongong, Mullaloo, Grong Gron, Yaramalong.

 

The first language probably developed as a series of babblings which would set the mood of a situation. More significance would lie in the tone of these ramblings than in any content. For example a stress situation (where an attack by a rival group is imminent) would produce vocalisations very different in tone from those during a celebratory situation, even though the content may be the same. This is basically the system of communication birds have adopted.  Flocks perched on trees maintain a general back-ground chirp which can suddenly change to a screech at the onset of a perceived danger. Many primates also practice this system.

 

Gradually a repertoire of nouns would be introduced to the babblings, and this would make communication more effective. Many animals would be given a name and this name would likely describe the characteristic sound the animal made. A hiss, for example, might denote a snake - or  gaa  a lion. Note that I avoid the r’s of a lion roar because at this stage these apes may not have been able to produce r sounds; the nearest possible sound representation of a lions roar would be used.

 

Arbitrary names would be given to food plants to distinguish one from another. Other names would be given to different geographical areas in order to describe territories for hunting. New names would add to the communal vocabulary and general knowledge would accumulate over successive generations.

 

Heavy gesticulation would accompany all babbling to reinforce messages. In time a crude syntax would evolve where these nouns would appear at a certain point in a babbled sentence. Say for instance the ape may want to warn his companion of a lion up on the far rock. A rule would become standard whereby the gaa (lion word) comes very near the beginning of the babble and the name for the rock (say bong) comes at the end of the babble ‘sentence’. The pitch and speed of the babble would indicate the relative seriousness of the situation. At the same time, the ape would likely point his finger in the appropriate direction. These rules of word placement in sentence structure and ways of gesticulating, perhaps established two million years ago, still survive today and are recognised throughout the world. I would expect that lion, the subject noun, comes long before the noun for rock in all languages.

 

The majority of communicative actions like  the nod of approval, or the sideways movement of disapproval, are long established and standard throughout the world.

     

This crude system of communication would refine itself over thousands of generations and more arbitrary rules of grammar would be laid down permanently.   

 

Hand Tools

 

The Savannah Ape hands would retain the simian single crease pattern for some considerable time but there would be constant selective pressure for increased dexterity and motor control in holding crude implements and throwing stones or wooden clubs at small animals .

 

The characteristic oblique three crease palm of modern humans probably evolved through selection of savannah apes using hand axes. Those apes which could make better hand axes would have a higher rate of survival, and thus a proportionately greater number of offspring. Flint is a common rock found in many parts of Africa. Obsidian (a naturally occurring glass) is associated with areas of volcanism in that area too. These materials were probably selected by savannah apes for making crude weapons. Both materials can splinter into shards - leaving sharp edges. The first weapons will have been naturally occurring pieces of these materials - of a suitable size to hold in the hand. Only one part of the stone or glass needed a sharp edge and the rest of it needed to be smooth enough for a reasonably comfortable hold.

 

To hold a hand axe properly, you need to cup your hand. The more modern hand is more capable of cupping than the primate hand, which is more effective at folding around cylindrically shaped objects such as branches.

 

Primarily these hand axes would be used for hacking carcases into pieces which would be easier to carry back to the nest area.  

 

Eventually they would discover that hitting one flint against another would knap off a piece leaving a new sharp edge. Better still - a series of delicate blows to the edge of the flint would create an extended sharp area around the lower edges.

 

These crude implements would  be capable of sharpening the ends of their digging sticks - to make a spear which could be thrown at, say, a herd of gazelle at a water hole. A small herd would present a broad target for such a weapon - even if it were thrown without much expertise.

 

The ability to successfully surprise animals at water holes and spear them to death would be the beginning of a new era of the savannah ape and the beginning of their domination of all other species.

 

 

 

 

Modern human

Reversion to baby gorilla

braincase  architecture

Homo erectus

Crude hand axe