We share our lives on this incredible planet with many other creatures, each of which has its own special trait or survival skill, a characteristic attribute by which it can be defined. Our special trick gives us the impression that we are in some way elevated above other animals, but of course we are not; it is important to remember that we are mammals, upright walking creatures, descended from an ancient line of apes believed to have originated in Africa. With a free thumb, we have the ability to fashion tools easily. It is believed that we have been making tools for more than 2.5 million years. Yet that does not define us. Other animals can make tools, too: sea otters use stones to break open oyster shells, and other primates even fashion weaponry for hunting.

What I believe defines us as human is our mastery of fire. Before we assume that we are the only users of fire in nature, we should think again. Just last year I watched hawks in Australia pick up burning sticks from a bushfire and drop them to spread the fire, flushing out or scorching potential prey. But no other creature has been found who can make fire at will.

In the world of archaeology, the earliest sign of human control of fire is a hotly debated topic, with few definite remains surviving from such antiquity. However, evidence appears to show fire hearths dating from one million years ago. It is reasonable to assume that fire was originally obtained from natural sources such as bushfires, which could then be kept burning.

Even today, there are peoples such as the Bayaka pygmies of the Congo Basin who carry fire with them, hardly ever needing to kindle a flame because, as they told me, “We don’t let our fire go out – it is the oldest fire in the world.” I have also worked with Australian Aboriginals who historically could not make fire and who would have to send runners to bring back fire from distant neighbouring tribes if their fire was allowed to go out.

Fire altered humankind’s potential forever. Now, we wielded a tool powerful enough to keep even the most ferocious early Palaeolithic predators at bay; the fear of nocturnal dangers was dispelled; and the fire became a focus for life, around which our forebears could gather in good cheer. (That sight is still played out nightly in the villages of the San Bushmen of the Kalahari.)

In the flames and coals of their fires, our ancestors learned to alter their food, to improve its flavour, to neutralise plant toxins and destroy harmful bacteria. Consequently our dietary range grew and diversified. It has been argued that our “fire-improved” diet may well have been a catalyst for the development of our large brain.

Until fire was harnessed, the length of the day was determined by sunlight; firelight extended the working day, made time available to communicate, to share ideas and be creative. In the sign language of Native Americans, the concept of meeting for a talk is defined by coming to a fire and sharing ideas, and even today the footlights of our theatres mimic the flickering light of a fire on the face of an ancestral storyteller.

We don’t have to have been there to realise that the question of how to make fire from scratch would have occupied the minds gathered at the campfire. If I could travel back in time I would hope to witness the first of our ancestors achieving this remarkable skill. The consequences of that first ember were astonishing. No modern invention comes close in importance to the creation of the first fire.

For more than 30 years I have been teaching students how to make fire, by every primitive means known. Although we will never know which was the first method of fire-lighting, some things never change. Each time a student succeeds in friction fire-lighting, their face lights up with a huge sense of achievement. Like an ancient ritual, the drama of the first fire is relived.

Being able to make fire at will brings confidence. Our ancestors were able to spread out, exploring their landscape in smaller foraging parties with fire for safety and with smoke to locate each other again. (I have witnessed Aboriginals in Australia’s Arnhem Land watching for smoke across flooded swamps to track the movements of family members.) Now, even colder landscapes posed little obstacle as our ancestors migrated across the planet, perhaps clinging to the unexplored coastline or following seasonal migrations of game inland.

The fireside became our most important laboratory. Here, as we stared into the flames, we observed the way fire could transform materials. We learned to harden the points of wooden spears, to soften thermoplastic tree resins and use them as adhesives to haft stone points. Here, too, we would discover that clay could be hardened into pottery. The process of scientific investigation was reinforced along the way through observation, hypothesis and experimentation. Inevitably we discovered metal and the rest is history. Everything flows from here, from the clothes we wear to the incredible devices contained in our pockets and the means by which my words reach you now. All this derives from our mastery of fire.

You have only to observe the face of an infant gazing into a fire to realise how deeply our fascination with it is rooted in the human mind. Fire has given us power and allowed us to modify the very landscape within which we evolved.

Perhaps the question we should be asking is this: how will humanity be judged to have used its special skill?

Ray Mears is a broadcaster, author and founder of the Woodlore school of bushcraft

The “What Makes Us Human?” series is published in association with Radio 2’s Jeremy Vine show