Burnt Bones Suggest Humans Used Fire 1.79 Million Years Ago, Study Finds

Early human ancestors may have been deliberately bringing fire into a South African cave as far back as 1.79 million years ago, according to a new study that pushes the record of hominin fire use deeper into the past than most previous evidence. The findings, published in the journal PLOS One, come from Wonderwerk Cave, a vast cavern in South Africa's Northern Cape that has long been a treasure trove for researchers studying human origins.

Archaeologists working in an older, deeper layer of the cave known as Stratum 11 found signs of repeated burning in deposits dating to between about 1.07 million and 1.79 million years ago. That places the site among the oldest known records of fire use by human ancestors, likely Homo erectus, an upright, large-brained species that ranged across Africa and Eurasia during the Early Pleistocene.

To detect the ancient fire, the team used a new technique called bone luminescence. Researchers shine high-energy blue light on grayish and white fossils under a microscope; bones that were once heated glow a vibrant red when viewed through a special filter, revealing burning that is invisible to the naked eye. The method allowed scientists to identify scorched bone even in sediments that had been buried for well over a million years.

A key part of the argument rests on geography inside the cave. The burnt material came from deposits at least 30 meters from the entrance, deep enough that a natural grass or bush fire sweeping in from outside would have struggled to reach. That distance, the researchers argue, makes accidental ignition from a wildfire unlikely and points instead toward fire that was intentionally carried inside and tended.

The picture that emerges is not necessarily of ancestors who could spark a flame on demand, but of hominins who knew how to harness it. The evidence suggests early humans captured fire from wildfires burning outside, brought it into the shelter of the cave, and maintained it until it burned out — an early stage in humanity's long relationship with one of its most transformative tools.

Mastery of fire reshaped the human story, enabling cooking, warmth, protection from predators and a focal point for social life. By extending credible evidence of controlled fire back toward 1.8 million years, the Wonderwerk research adds weight to the idea that this pivotal behavior emerged remarkably early, among ancestors far more ancient than our own species, Homo sapiens, which would not appear for well over a million more years.