HOW LANGUAGE EVOLVED AND COLLECTIVE LEARNING

Many animals call to each other with sounds that stand for “Danger!”, “Food!”, or “Here!”, but only humans can think conceptually – can talk, for example, about the nature of food or danger. For this, language had to evolve, and with it came story-telling, information-sharing, and our first attempts at understanding the world.

In evolutionary terms, the ability to speak emerged as a result of the hominin larynx lowering in the throat, enabling our ancestors to produce more diverse sounds than those of any other primate. The biological price of this was high, as an elevated larynx had enabled us to breathe and swallow simultaneously; now, we ran the risk of choking when we ate.

At the same time, the hyoid bone, which connects the larynx to the root of the tongue, also changed position in a way that helped facilitate vocalization. Judging from the fossil record, this happened between 700,000 and 600,000 years ago, as Neanderthals and probably our common ancestor both had a “modern” hyoid bone. Our exceptional breath control, essential when speaking, also seems to date from this time.

Casts of fossil skulls show that Neanderthals had structures in the brain that were equivalent to our own “Broca’s area”. This area is vital to speaking and understanding language, and to perceiving meaningful gestures. Indeed, gestures may have been key: studies show that chimpanzees repeatedly use hand signs when vocalizing, indicating that early language may not have been purely vocal. However, the functions performed by different parts of the brain can change over time, so even if other hominins had brain structures similar to ours, they may not have been used for language.

SYMBOLS AS EVIDENCE

The artefacts left by our ancestors are better forms of evidence. Among the most striking are those created by early Homo sapiens in South Africa between 100,000 and 50,000 years ago. At Blombos Cave, for example, red ochre blocks were shaped and carefully covered with delicate cross-hatch designs. Even more impressive are the ostrich eggshells found at Diepkloof Cave, also in South Africa. These were engraved with complex geometric patterns that show changes over time, hinting at shifts in meaning. Very much older than these, however, is a seashell from Trinil, Indonesia, which bears the incised zig-zag markings of a Homo erectus who lived some 540,000–430,000 years ago. It reveals that the common ancestor of several hominins used graphic symbols, and so had probably developed language – a fact that is supported by anatomical evidence.

Another type of symbolic evidence comes from personal ornaments, which often communicate social meanings – for instance,about personal status or group affiliation – which can only be established through language. For example, the first use of shell beads occurs at the same time as engravings become more common; beads from Skhul Cave in Israel date from 135,000–100,000 years ago, while those from Grotte des Pigeons in Morocco date from 80,000 years ago. At Blombos Cave, too, groups of beads were excavated from layers dating from around 80,000 years ago, many showing areas of polish that suggest they were strung together, possibly as necklaces. The markings also show that the arrangement of the beads changed over time, suggesting not only that they were symbolic, but that their meanings evolved, like those of the Diepkloof eggshells.

FROM SYMBOLS TO STORIES

Taken together, the evidence shows that Homo sapiens had evolved symbolic culture and language by 70,000 years ago – and that Neanderthals did this independently. However, the evidence for language being used in narrative, story-telling senses comes much later, after 45,000 years ago. For example, the famous Lion-man ivory statue from Hohlenstein-Stadel, Germany was carved around 40,000 years ago. It merges a lion’s head with a human body, indicating both an imaginative leap by the artist, and a narrative to give it meaning.

The most striking examples of Palaeolithic narrative come from later European cave art. One scene painted at Lascaux, France, around 17,000 years ago, features a wounded bison charging a male figure who lies above some fallen spears and a line topped by a bird. There are many interpretations of the scene, but all of them agree that the man, the bison, and the bird only make sense in a story-telling context. This and other examples indicate that rich oral traditions, full of meaning and symbolism, were part of Palaeolithic life, and likely had been for many thousands of years. They were our first attempts at fathoming the world around us – of giving it a narrative shape.

COLLECTIVE LEARNING

The emergence of language set Homo sapiens apart from other species: with language came the ability to share and store information across generations. This ensured that new generations could know more than the last, and so be more effective in the world.

The practice of sharing and storing information is called “collective learning”. At its simplest, this means that we only need invent the wheel once, for that knowledge can then be stored and shared publicly. The alternative is to imagine us as a group of networked computers. Without the network – without connectivity – how could human history unfold?

SURVIVING COOPERATIVELY 

Humans appear to be predisposed to work together to a far greater degree than other animals. The roots of this tendency can be seen in primates, the majority of which live in social groups, with strong kin relationships and friendships. However, humans live in unusually diverse societies, and our high level of cooperation is a unifying characteristic.

Hunter-gatherer groups, for example, typically number between 25 and 50 individuals, but they are usually part of extended social networks, consisting of blood relations and other types of kinship. Within and between these groups, food, labour, and childcare are shared – as is vital information about water, predators, and the availability of food.

The evolution of this ability to cooperate can be seen in the archaeological record. Stone tools began to be transported increasingly long distances around 200,000 years ago, pointing to expanding social networks. By then, multi-part tools, such as spears, were being made, probably collaboratively. More spectacular examples of these, such as atlatls and bows, came later, and after 40,000 years ago many of these were lavishly ornamented. The Mas d’Azil atlatl, for example, is one of five almost identical objects found at different sites in the Pyrenees. Each is carved into the shape of an ibex, demonstrating a common artistic tradition, and probably some level of apprenticeship. Moreover, an atlatl, like a bow, is a “tool for using a tool” – in this case a tool for propelling spears – which is of a whole new order of complexity. It shows that by 17,000 years ago we were adapting ourselves ever more cleverly to our environment – alone of all creatures through cultural rather than genetic change. Thanks to collective learning, human history could begin.

By Rebecca Wragg-Sykes in "DK Big History", editor Kaiya Shang, MacQuarie University Big Story,DK Penguin Random House, London, 2016, excerpts pp. 202-205. Adapted and illustrated to be posted by Leopoldo Costa