The lost languages of ancient humans: Listen to stone-age chat

The bones of our ancestors remain silent. So, how can we possibly imagine what our earliest languages sounded like? Paleoanthropologists study millions of years of fossil evidence to try and reconstruct the voices of the past.

Human language is unique among all forms of animal communication. As far as we know, we – and we alone – are able to translate our thoughts and experiences into a vocabulary of mental symbols that we can then rearrange and reassemble to portray new ideas, and to convey meaning to others.

The beginnings of language, however, remain shrouded in mystery. Scientists are gradually piecing together millions of years of clues – from fossilised bones to ancient art – and a clearer picture is starting to emerge. 

There are two main theories on how language came to be.

The first view is that language appeared suddenly, spontaneously emerging with the evolution of human intelligence, at the point in time humans developed the ability to have abstract, symbolic thoughts. Until recently, scientists thought this happened in Europe around 40,000 years ago but new discoveries of abstract art and hand-crafted tools – found across the globe – have called this into question, suggesting we might have missed the mark by millions of years and thousands of miles. 

"The majority of what you express is abstract: emotions, projects, objects that we do not have directly in front of our eyes," explains Amélie Vialet, a paleoanthropologist at the National Museum of Natural History in Paris. "Language necessarily calls upon abstraction and imagination for both the speaker and the receiver."

Of course, thoughts don't fossilise. To identify when the emergence of abstract thought might have happened, scientists therefore look for archeological proxies – physical evidence like art on cave walls or crafted stone tools.

James Cole, archeologist and dean of applied sciences at Brighton University, studies the evolution of cognition and complex thinking through the development of the "hand axe", a tool cut from stone which first appeared around 1.8 million years ago.

"Hand axes are interesting stone tools because they are the first time that we see an imposition of deliberate form," he says. "To impose form, you've got to have a preconceived idea of what that shape is. To hold that idea in our heads means that we have an ability to imagine."

That capacity for abstract thought, suggests Cole, may also be the bedrock of language. Take the word "tree", he explains. "The word doesn't bear a relationship to the object in the way that a sign or a symbol might. So, the label has to gain traction through a commonality of understanding within a cultural group. So when I say the word tree, you know it's a tree."

Being able to talk about ideas and the past and future, rather than just expressing feelings in the moment, would have been useful and often life-saving, helping humans to make plans, coordinate, innovate and adapt to different situations and habitats. Because it was so useful, and our species was generally physically able to do it, this new skill of chatting might then have spread. 

The second view is that language development is ancient and selection-driven. This theory supposes that language evolved gradually. 

The position of the vocal tract, the structure of the brain and the size of the spinal cord evolved slowly into the modern human form, over millions of years, indicating the human capacity for language and speech may also have developed over a very long time. As our sounds and vocabulary became more varied and precise, we would have gained an important evolutionary advantage through language-related survival skills such as strategising, solving complex problems and forming social bonds.

What would those early utterings have sounded like? Vialet, alongside a team of researchers and in collaboration with Radio France, has used scientific insights to try and recreate them.

Modelling ancient brains

"We know a lot and a little about language at the same time," says Vialet. "From a fossil skull, it is possible to observe many things to better understand our evolution." By analysing the skeletal remains and the evolution of physical features related to speech production, says Vialet, we can identify the sounds ancient humans may have been able to produce.

But working with just the bone has its limits, she adds, as the soft tissues are the determining factor when it comes to function. "It is a challenge because [soft tissues] cannot be preserved." Her solution is to reconstruct them using biomechanical models: mathematical representations of our bodies and functions. To do this, Vialet examines the "traces" – imprints – left behind on the........

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