By examining fossil skulls, ancient tools and traces of early behaviour, paleoanthropologists are gradually building a picture of how human language may have emerged.

Human language is unlike any other communication system in the animal world. Humans can transform thoughts, memories and experiences into symbolic words. These words can then be combined in countless ways to share ideas and create entirely new meanings.

Exactly when this extraordinary ability began is still uncertain. According to a report published in the BBC, researchers are working with clues scattered across millions of years of evolution, from fossil remains to prehistoric artwork.

Two ideas about how language began

Scientists generally propose two major explanations for the origins of language.

One view suggests that language appeared suddenly once humans developed the ability for abstract thinking. According to this idea, when early humans began to imagine things that were not physically present, such as plans, emotions or future events, language emerged rapidly to express those ideas.

For many years researchers believed this shift occurred about 40,000 years ago in Europe. However, discoveries of ancient symbolic art and carefully crafted tools across Africa and other regions suggest that complex thinking may have developed much earlier.

Amelie Vialet from the National Museum of Natural History explains that language depends heavily on imagination and abstraction. Much of what people talk about involves concepts that are not directly visible.

Since thoughts cannot fossilise, scientists look for indirect evidence of abstract thinking. Archaeologists often focus on objects such as tools or artwork that required planning and imagination.

James Cole at University of Brighton studies the famous prehistoric stone tool known as the hand axe. These tools appeared about 1.8 million years ago and show that early humans deliberately shaped stone into a specific form.

Creating such tools required a mental image of the final result. According to Cole, the ability to hold that imagined form in the mind may also have laid the foundation for language.

Language evolving slowly over time

A second theory argues that language did not appear suddenly but instead evolved gradually.

Over millions of years, several parts of the human body changed. The vocal tract shifted, the brain grew larger and more complex, and the spinal cord adapted to support greater breath control. These changes slowly expanded the range of sounds humans could produce.

As communication improved, it likely gave early humans important advantages. Language helped people cooperate, plan hunts, share knowledge and form stronger social bonds.

Because soft tissues such as the tongue and vocal cords do not survive in fossils, reconstructing ancient speech is extremely difficult. Researchers must rely on clues preserved in bones.

Vialet studies marks left inside fossil skulls that reveal the shape and size of ancient brains. Some of the oldest examples come from fossils of Australopithecus afarensis that lived more than three million years ago.

Over time the human brain became larger and more interconnected. This growth likely increased the ability to process information and develop complex communication.

The tongue also plays a crucial role in speech. Although the organ itself does not fossilise, surrounding bones provide hints about how it might have moved. The tongue shapes airflow to produce different sounds, allowing rapid changes in speech.

Using this anatomical evidence, Vialet and collaborators worked with Radio France to recreate possible ancient vocalisations.

27 million years ago: The origins of vowel sounds

Research suggests that some building blocks of speech may be extremely ancient. A 2019 study from the University of Alabama examined vocalisations in primates.

The study found similarities between human speech sounds and those of baboons. This suggests that the ability to produce contrasting vowel sounds might have existed in a common ancestor shared with Old World monkeys about 27 million years ago.

Vowels are essential because they help distinguish words from one another.

3.2 million years ago: Lucy

One of the most famous early human relatives is Lucy, a member of Australopithecus afarensis who lived about 3.2 million years ago in East Africa.

Lucy likely produced sounds similar to modern chimpanzees. Her high larynx would have limited the variety of vowels she could make. Her communication may have consisted mainly of emotional calls and gestures rather than structured sentences.

Still, those sounds may have helped her group warn each other about predators or react to new discoveries such as early tools.

1.6 million years ago: Turkana Boy

A major step forward occurred with Homo erectus. The fossil known as Turkana Boy, discovered in Kenya, lived about 1.6 million years ago.

Unlike earlier ancestors, Homo erectus had a body adapted for long-distance running and an upright posture. These features improved breath control, which also helped produce a wider range of sounds.

Inside Turkana Boy’s skull scientists identified an imprint of Broca’s area, a brain region associated with language and tool use.

According to Steven Mithen of University of Reading, Homo erectus may have used simple “iconic” words. These words imitated real-world sounds or sensations, similar to modern expressions like “buzz” or “splash”.

Language at this stage may have allowed early humans to coordinate hunting, explore new territories and share practical skills.

50,000 years ago: Neanderthals

Neanderthals were intelligent and resourceful humans who lived across Europe and parts of Asia. One famous fossil, known as Gibraltar 1 or Nana, dates to about 50,000 years ago.

Evidence shows that Neanderthals hunted animals, produced tools and buried their dead. Their brains developed in a way similar to modern humans, suggesting sophisticated cognitive abilities.

Their voices may have sounded somewhat nasal because of larger nasal cavities and lung capacity. However, some scientists argue that Neanderthals possessed the anatomical features required for full speech.

30,000 years ago

By the time early Homo sapiens appeared in Europe, the full package for language existed. Fossils such as Cro-Magnon 1, discovered in France, show that modern humans had vocal tracts and brain structures almost identical to ours.

This allowed them to produce the complete range of speech sounds, including the vowel “i”. Combined with advanced cognitive abilities, humans could now communicate abstract ideas, tell stories and develop culture.

Today more than 7,000 languages exist around the world, though many are endangered.

Language continues to evolve as societies change. Yet some traces of ancient speech may still remain. Mithen notes that words for “mother” in many languages share the sound “m”, possibly originating from the sounds babies make while nursing.

Even as languages transform, they may still carry faint echoes of voices from deep human history.