Wonderwerk: Hearths Dated Between 1 and 1.8 Million Years Confirm Homo Erectus's Control of Fire

Wonderwerk Cave: A Sanctuary of African PrehistoryPrehistoryThe span of human history before the invention of writing, from the Palaeolithic to the Metal Ages, known mainly through material remains.→

Nestled in the Kuruman Hills in the heart of South AfricaAfricaThe cradle of humankind: the continent where the first hominins appeared, then Homo sapiens around 300,000 years ago, before the expansion to the rest of the world.→'s Northern Cape province, Wonderwerk Cave is one of the continent's most exceptional archaeological sites. Its name, meaning "miracle" in Afrikaans, was given by settlers who found shelter there. More than 140 metres long, this karstKarstA limestone landscape shaped by rock dissolution, rich in caves and passages; its sediments can preserve bone and DNA over long timespans.→ tunnel carved through Proterozoic dolomite preserves sediments accumulated over more than two million years of near-continuous homininHomininMember of the subtribe Hominina, comprising the human lineage (Homo, Australopithecus, Paranthropus…) but excluding orangutans and gibbons. The term progressively replaces "hominid" in its narrow sense.→ occupation. The stratigraphic sequence, exceeding six metres in depth, offers prehistorians a unique window into the behavioural evolution of the earliest members of the genus Homo in Africa.

Excavations begun in the 1940s, and resumed systematically since 1978, have established a detailed chronology of occupation. It is in layer 10 of this sequence, located approximately 30 metres from the cave entrance, that a new study published in 2026 in the journal PLoS One has identified tangible evidence of fire use by hominins between 1.07 and 1.79 million years ago.¹

Bones Burned at 300-600 Degrees: What Do the Analyses Reveal?

The team led by Maria Dolores Marin-Monfort (Museo Nacional de Ciencias Naturales, Madrid) subjected the bone fragments from layer 10 to two complementary techniques. Fourier-transform infrared spectroscopy (FTIR) analyses the structural changes in bone mineral induced by heat: when bone is exposed to high temperatures, its hydroxyapatite crystals reorganise in a characteristic way. Results show that these bones were exposed to temperatures between 300 and 600 degrees Celsius - a range that corresponds precisely to a maintained domestic fire, not an accidental surface burning.

The second technique, bone luminescence datingLuminescence datingA method dating the last heating or light exposure of sediments and minerals by measuring energy trapped in the crystal.→, exploits the fact that bone minerals accumulate energy when thermally exposed, then release it when stimulated in the laboratory. The amount of energy accumulated since the last heating event allows researchers to date it. Dates obtained place the formation of these burned remains between 1.07 and 1.79 million years before present, a result fully consistent with the independent chronology established for this layer through radiometric methods.¹

Among the bones analysed are remains of large mammals bearing both cut marks (indicating deliberate food processing) and thermal signatures consistent with controlled-fire cooking. This dual evidence - alimentary exploitation and thermal transformation - points to sophisticated, planned behaviour.

Why 30 Metres of Depth Changes Everything

One of the study's most compelling arguments concerns the location of the burned sediments. Layer 10 lies approximately 30 metres from the cave entrance - a depth at which no natural fire, whether lightning-ignited, bush fire, or volcanic activity, can penetrate. This straightforward geographic evidence definitively rules out accidental burning and attests that hominins were deliberately bringing fire inside the cavity.²

The distinction between fire mastery and fire production is fundamental to prehistoric research. Producing fire from scratch - using percussion or friction - is a technique whose oldest incontrovertible evidence dates back only around 400,000 years. Transporting and maintaining embers, on the other hand, is a different competence: it demands continuous attention, anticipation of future needs, and likely a social organisation capable of dividing this labour. The excavations also revealed AcheuleanAcheuleanLower Palaeolithic technical culture characterised by hand axes, present across three continents.→ stone tools in the same layer, confirming that Wonderwerk's occupants were most likely Homo erectus, a species whose cranial capacity already reached about 70% of our own.

These new dates push back previous fire evidence at Wonderwerk by around 300,000 years, which had previously been documented at approximately one million years. They now place this South African cave at the centre of debate on the origins of a behaviour that would profoundly transform human history: food cooking, protection from predators, and sociality gathered around the hearth.