Posts Tagged ‘bonobos’

4. How we became humans 1

Eight millions years ago [8 mya] our ancestors were normal animals. They were apes. Our ‘nephews’, the chimpanzees and the bonobos, still are apes and normal animals. Apes live in rainforests. When the place where our earliest ancestors lived had not been changed, we would still be apes and normal animals.

However, from 10 mya the climate was becoming cooler and dryer. Rainforest needs heat and wetness; so the rainforest belt, in early Miocene reaching over southern France and Italy, shrank and 8 mya our ancestral jungle turned slowly into open savannah. It is here where our story begins.

Frans de Waal (Bonobo 1997) says that, when we want an image of our earliest ancestors, we can look at the bonobos. They are the only kind of chimpanzee whose environment never changed. A species only changes when its environment changes. The environment of our earliest ancestors changed totally, so our earliest ancestors changed totally. The environment of the ancestors of the chimpanzees changed much later and somewhat, so the chimpanzees changed somewhat.

Here, we will name our earliest ancestors ‘our ANBOS’ (ancestor-bonobos).

It took tens of hundred thousands of years for their jungle to turn into a savannah. The ANBOS never had any idea of this change; for them the world was in every phase like it always was. So the adaptations to the new conditions passed unnoticed. But for our story these adaptations are crucial.

The savannah is a diversified environment consisting of open woodlands mixed with impenetrable shrubs and grasslands accommodating herds of many kinds of grass eaters.

Our ANBOS lived in the woodlands, where they spent the nights in nests high in the trees. But these woodlands along the shores of rivers and lakes didn’t contain the fruit trees their ancestors used for sustenance. For their food, our ANBOS had to roam the open grasslands which was very dangerous because of the big cats that preyed on the grass eaters. Big lions, sabre toothed tigers and similar species were formidable predators. The sabre toothed tigers were specialists in preying on pachyderms: rhinoceroses, hippopotamuses and (ancestors of the) elephants. In a short sprint the sabre tooth ran under them and ripped open their bellies with their sabre teeth. The mighty colossus was felled and after his downfall the ‘tiger’ fed on the entrails only. The sabre teeth were too frail for the rest of the cadaver. The rest of the carrion was left to the giant hyenas. Nature is cruel and doesn’t know empathy.

What I emphasize: the Miocene (22 – 5 mya) savannah was characterised by megafauna and was much more dangerous than the current Serengeti. Though the little ANBOS were much stronger than we are now, they needed special armament to roam the grasslands safely.  As normal apes, they protected themselves by throwing anything they could grasp at their predators.

Jane Goodall tells the story of Mister Worzle. The bananas she put down for the chimpanzees in order to keep them in her neighborhood for studying their behaviour, also allured baboons (a large and brave monkey) who frightened some female chimpanzees. But Mister Worzle did not give a centimeter of ground and threw anything he could grasp: grass, branches, one time a bunch of bananas (the baboons were happy!). But soon he discovered that stones worked and soon found out that bigger stones worked even better.

5. How we became humans 2: Stones

Our ANBOS had to become professional stone throwers. They could not safely take a step on the open grasslands without their armament of stones. One stone was not enough to ensure their safety; they needed a handful of stones.

But how can apes carry a handful of stones? On the open grasslands, plenty of animal hides could be found. Sabre toothed tigers ate the entrails of their kill. The hyenas with their mighty jaws were capable of eating the rest of the carcass, including bones, but left the basically inedible, hairy hides. So the ANBOS used those animal hides to carry things; and with their long experience in braiding their sleep nests, knitting these hides together was easy. But how would apes carry bags filled with stones? How do bonobos and chimps carry heavy things? They use their hands, and in order to do so they must walk upright on their feet.

In tens of hundreds of thousands of years our ANBOS, having no other choice, turned into ‘professional’ bipeds with longer and stronger legs, special pelvic and buttock muscles, special midriff, and adapted blood circulation. At least they began to develop these features in a way that was good enough for foraging on the savannah. They still kept the climbing facilities of their hands and feet: it was not safe to sleep on the ground, so they still had to make their sleeping platforms high in the bushland trees.

Females had to carry their babies and gather food for themselves and the rest of the group, so they couldn’t carry and throw stones. Males couldn’t gather food: they had to protect the others, because the predators were always watchful for moments of inattentiveness. So from the very beginning, our ANBOS cultivated a division of labour. Women and children gathered the food: grass seeds, tubers and roots (with digging sticks), larvae and insects, eggs and small animals. The adult men did nothing but provide safety. The groups with the most effective behavior flourished, kept more young alive and soon outnumbered the groups that were clumsy at these things. In tens of hundreds of thousands of years, through hundreds of generations, the most adept populations survived.

The same mechanism applies to group harmony. Bonobos live in female-dominated groups characterized by group harmony. They solve all tensions with sex. It is clear that our ANBOS ‘professionalised’ this behaviour too. Nice breasts and buttocks for the women (the ‘attractive’ red vaginas of the chimpanzee-women and heavy scrotums of the males were not maintainable for bipeds), large penises for the men, and continuous sexual willingness and unnoticeable oestrus of the women are all mechanisms for reducing tensions.

Didn’t the men hunt? No way. The bipedal speed was insufficient to keep up with the savannah predators. But thanks to the presence of predators such as sabre toothed tigers, there were hides all over the place, leftovers of the other carnivores of the savannah. The hides provided a new niche for the handy apes. The ANBOS could pick and scrape protein-rich tissue from the hides with the sharp edges of bones, shells and stones. And when a hide was totally clean, it made a perfect bag for carrying things, a blanket on cold nights, a screen against sun, wind, or rain, or a practical canvas for stone tools. The multipurpose hides were the ANBOS’ most valuable property. The ‘paleos’ lack attention for the importance of these hides in the technical development of our ancestors. It was the beginning of ‘the stone age’: the beginning of the use of stone flakes for processing hides.

All these environmental changes and physical adaptations developed unperceived by our ANBOS. Just like normal apes 10 million years ago, they made their daily foraging tracks in a vast territory. In the course of two million years even more open grasslands became part of their territory and daily route. All needed adaptations developed during this time. By 6 million years ago, our ANBOS were experienced savannah dwellers.

They had evolved into a new kind of chimp, a totally new species in the history of life on earth: the australopiths. The only thing which remained unchanged was their way of life. They would leave their nests early in the morning, wander along a route they knew perfectly, gathering food along the way, and finally come to the next wood where they would share the gathered food and then make their nests high in the trees. The only part of the routine that changed was that instead of eating their food while ranging on the woodlands, they carried most of the gathered food (tubers, grass seeds, larvae, eggs, and so on) to their camps to be distributed equally among group members.

99.5 % of the time we exist, our ancestors were hunter-gatherers. This is an important fact for understanding ourselves.

9. The second big jump to humanity: fire.

We are not sure which fossil, if any, belongs to the population of animals that could name things. Brunet, head of the French group which found the 6-7 million year old hominid skull in Chad, is shown with the skull, saying: “It’s a lot of emotion to have in my hand the beginning of the human lineage…” But there is no label on the skull, and it is impossible to know if the skull in his hand is from an ancestor-bonobo, or from a prey of the ancestor-bonobos.

Around 2.5 million years ago, the ancestor-bonobos evolved into ancestor-australopiths. There is proof of their existence: not a skull, but stone tools.

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At 15 locations east and west of the Kada Gona river, Ethiopia, Sileshi Semaw and his team recovered more than 3000 surface and excavated artifacts, dated 2.6 –2.5 million years ago. [Journal of Archaeological Science (2000) 27, 1197-1214]

Makers of these well-flaked artifacts: Australopithecus garhi. Archaeological name of these earliest stone industry: Oldowan.

Other early Oldowan sites, older than 2 million years ago: Olduvai, Omo, Bouri, Lokalei.

All these 2.5 million years old artifacts were found together with animal bones, many of them with stone-tool cut-marks. A recent publication[1] about cut-marks on bones from the Dikika site in Ethiopia demonstrates that stone ‘knives’ for processing of bones of scavenged carcasses may have been used even earlier: 3,4 million years ago. So these artifacts are butchery tools: the cut-marks on the bones are the result of “hunting and/or aggressive scavenging of large ungulate carcasses”.

To me, these Kada Gona tools are the hallmark of the second big jump of our ancestors, as the consequence of the first jump: names for the things. It was the climate again that triggered the jump. For five million years, the climate had been stable without giving much reason for changing behavior. But then the Ice Ages, the periodical increase of ice caps on the poles and around the high mountains, began. Now there were cold periods (stadials, maxima) interspersed with warm periods (interstadials, minima). It started with a dramatic cooling and drying. Jungles receded to a narrow and interrupted belt around the equator; savannahs turned into deserts. There were ever less trees to sleep in, ever more natural fires.

The ancestor-australopiths knew some attractive qualities of fire, and they were not the only animals who were lured by the far clouds of a natural fire. Vultures and other carrion eaters and even antelopes approached carefully, enticed by carrion and salty ashes. The females that could name things knew that some tubers and other plants, normally not edible, were edible after the work of the fire.

Why women again? Women have to feed their children. In everything they do, they are motivated by the need for more and better food for their children. Perhaps this time it was an old and experienced woman, a grandmother who had the courage to take a glowing branch of an smoldering natural fire. Trembling with fear, she took it to a safe place, fed it with dry grass and wood and breathed in new life: fire.

Terrified, of course, the other ancestor-australopiths observed from a distance, screaming in fear at what the grandma did. She held a tuber on her digging stick in the flames. When she thought the tuber was done, she tasted it, went with the tuber to her granddaughter. Granddaughter would remember this moment ever in her life.

Too nice, this ‘just-so-story’? Then consider this: gorillas have been observed sitting near a smoldering fire in nights when the temperature on the savannah approached the freezing point. But no ape is known to ‘feed’ the extinguishing fire with combustible material.

But our ancestor-australopiths did: because they already had a name for fire, they gradually lost their instinctive fear of the fire and got a feeling of power over it. After this, of course it took many generations before they had developed the technique to carry the fire from one campsite to the other, as live charcoal in a bovine’s horn or in some similar way.[2]


[1] Nature, 12 Aug.’10
[2] If you don’t believe that such an early ‘taming’ of fire can be postulated, ask Ralph Rowlett of the University of Missouri-Columbia in Missouri.

11. the impact of fire control on communication

I started my fire-paragraphs naming it ‘a big jump’. The most important aspect of it comes now:  the impact of the campfire on communication.

Before this momentum of fire control, communication was limited to daytime: during the foraging hours and the food sharing upon reaching the next sleeping place. Before twilight, for safety purposes, everyone had to climb high in a tree to make a nest, which effectively ended communication. But now, with a campfire keeping predators at bay, they could rest and communicate all night long! Those nightly hours could be used for nothing else but communication. They began dancing and singing around the campfire. In my view, dancing and singing cannot be separated here, which why we may call it danced singing.

Why danced singing? I repeat: for our ancestor-bonobos, normal ape communication (cries, gestures, facial expressions and other body language) was extended with a humanlike component: names for the things. Those names were produced with hand gestures, not with cries. For apes have no neurological control over their voice: ape cries are controlled by the limbic system. But they weren’t deaf, like present-day sign language users. Their gesturing came with accompanying cries. In the long evenings around the campfire, the growing gestural communication with names for the things became a proto-form of sign language: physically no more than an extension of their ape body language. The screeches were a proto-form of singing. Later more about danced singing. First: What did they communicate?

One might say: nothing at all, they just wrapped themselves in a hide and went to sleep while only one of them (a man of course) kept his eyes open and the fire burning. Speculating in this way however, one might easily overlook that they were a subspecies of bonobos: fervent communicators! In their new, more dangerous habitat they lived in closer togetherness than their rain forest ancestors, so they needed to be even more social. The new circumstances in combination with their bonobo-like inclination had already lead them to their new habit of names for the things.

So: what did they communicate? I propose it was the exchange of thoughts, expressions of what was going on in their mind: in other words, they were sharing emotions. For example the memory of some shocking event in the past day. Communicating these emotions took the form of performances. Let me dish up a possible ‘performance’ here. The threatening encounter with the dangerous buffalo!

The men had made a line with their stones at hand. The buffalo had hesitated, perhaps he remembered an encounter with a troupe of those apes, resulting in a hailstorm of painful stones. He scraped with his hoofs. After some long lasting seconds the buffalo had turned his back and moved.

Now, quietly around the campfire, a woman, with that threatening event in her mind, got up and imitated it with emotional gestures. The others screamed in approval. A man jumped up and imitated the buffalo. The emotional screaming increased. Other men jumped up and made the defense line, with imitated stones at hand. Then the ‘buffalo’ slunk off, and the screaming became jubilation. And calm returned in the group. But the nice performance stayed in everybody’s mind, and after several quiet minutes some women jumped up again and repeated the performance. And again, and again, until everybody wrapped himself in his hide to go to sleep. Evening after evening they did ‘the buffalo’ over and over, until a new event was subject of a new performance.

Generations after generations similar nightly performances became ever more sophisticated, and the gestured communication too. Sophistication means that the gestured ‘words’ underwent standardizing and shortening. Because when the beginning of a gestured ‘word’ is already understood, you don’t need to finish the whole gesture. In a group of women gossiping by sign language and cries, each woman wants to contribute her share. (Why women? Hunting men make no noise. But gathering women chatter and laugh: noise chases serpents away.)

Expressing such emotional thoughts the person used her/his whole body (just like bonobos do today) with accompanying cries. The others responded with imitating gestures and cries, and many of them jumped up and joined the communicating person. And when communicating very emotional items, the whole group was dancing and crying, over and over. From generation to generation, this behavior became ever more ritualized, controlled and refined.

When I say ‘ritualizing’, I mean, as neatly formulated in Wikipedia, "behavior that is formally organized into repeatable patterns, the basic function of which is to facilitate interactions between individuals, between an individual and his deity, or between an individual and himself across a span of time." Ritual synchronizes the activity of participants, a phenomenon that contributes to group cohesion – which can also contribute to survival. Some scholars also suggest that human ritual behavior reduces anxiety. It makes me think of the ‘war dances’ of the Yanomamö , as preparation of a raid. A more modern example may be the ritual drilling of recruits in the barracks.

This development towards better expression through more refined body control affected both dancing and singing. First the dancing. Our ancestors were sharing emotions in an evermore ritualized mode of body language: their bodily expression of experiences, feelings and thoughts evolved into a kind of ballet, of formal dancing. In the course of this evolution, the specific gestures for specific meanings became more formally stylized. A more modern example of extremely stylized and formalized dancing is the 19th century Balinese religious dancing (as described by Dutch colonials) where women told a complex story without any word – just by dancing. In a way, present-day sign language for the deaf functions in a similar way: especially when this concerns a message with emotional content, the sign language may look like a kind of ballet dancing.

Next the singing. Our ancestors were like bonobos, so much more expressive than chimpanzees, who are more silent. Just like their dancing was gradually ritualized, the accompanying cries and calls underwent ritualizing in the evening-after-evening performances. Over the generations, this gradually led to better neurological voice control. The more meaning and information one can convey by voice, the more impressive and effective the resulting performance will be.

I will get back to this combination of dancing and singing later, in the context of the origin of our religious feelings.

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