An artificial intelligence tool has spotted changes in flints from a 1-million-year-old ancient human site called Evron Quarry in Israel. A closer examination reveals this is a significant discovery showing ancient humans used fire almost 1 million years ago.

The study conducted by scientists from the Weizmann Institute of Science gives researchers reason to renew the “perspective on the origin, evolution, and spatiotemporal dispersal of the relationship between early hominin behavior and fire use.

Archaeological excavations at Evron Quarry, 1976-77. Credit: Evron Quarry/Excavation Archive

Pyrotechnology is a key element of hominin evolution. The identification of fire in early hominin sites relies primarily on an initial visual assessment of artifacts’ physical alterations, resulting in potential underestimation of the prevalence of fire in the archaeological record,” the researchers write in their paper published in the journal PNAS.

Until now, evidence of fire use dating back to 500,000 years ago has only been found in five sites around the world making this new discovery highly significant as it gives a rare glimpse into the lives of early humans. it also seems other places should be added to the list where humans used fire a long time ago.

From left to right: Dr. Filipe Natalio, Dr. Ido Azuri and Zane Stepka. (courtesy, Weizmann Institute of Science)

“We may have just found the sixth site,” said Dr. Filipe Natalio of Weizmann’s Plant and Environmental Sciences Department.

Archaeologists say that preliminary results of the investigation indicate that the controlled use of fire by ancient hominins, a group that includes humans and some of our extinct family members developed around a million years ago – meaning much earlier than previously thought.

“The prevailing theory, called the “cooking hypothesis,” states that the use of fire was crucial for the evolution of homo sapiens, with flames not only enabling the creation of more sophisticated tools but also making food safer to eat and increasing its nutritional and digestive benefit — providing more nutrients for brains to develop and grow.

800,000-year-old flint tools found at the Evron Quarry in northern Israel. Credit: Zane Stepka

While the theory is widely accepted in the academic community, researchers have found it difficult to find evidence of fire use at the early stages of humans’ evolutionary development, and thus do not have the necessary data to fully support it.
Traditional archaeological methods allow for the discovery of fire usage to only as far back as some 200,000 years ago, since researchers rely mainly on modifications to material by heat, for example color changes,” the Times of Israel reports.

Under the supervision of Professor Avraham Ronen, scientists have previously excavated at the site of Evron and “uncovered 14 meters (45 feet) of animal fossils and tools from the Paleolithic era, dating back to between 800,000 and 1 million years ago, which made it one of the oldest sites in Israel.

However, researchers did not discover any evidence at the site of fire use.

Archaeological excavations at Evron Quarry, 1976-77. (Evron Quarry/Excavation Archive)

With ash and charcoal degrading over time, the finding of such evidence at the site is close to impossible.”

“When we started this project,” said Natalio, “the archaeologists who’ve been analyzing the findings from Evron Quarry told us we wouldn’t find anything. We should have made a bet.”

The use of artificial intelligence has been successful because AI has the ability to analyze the chemical composition of materials and from there estimate the templates they were heated in.

“We tested a variety of methods, among them traditional data analysis methods, machine learning modeling, and more advanced deep learning models,” said Dr. Ido Azuri, of Weizmann’s Life Core Facilities Department, who headed the development of the models.

800,000-year-old flint tools found at the Evron Quarry in northern Israel. Credit: Zane Stepka

“The deep learning models that prevailed had a specific architecture that outperformed the others and successfully gave us the confidence we needed to further use this tool in an archaeological context having no visual signs of fire use,” he said.

According to the Times of Israel, “analysis for the heat exposure of 26 flint tools previously found at the site showed some exceeding 600°C, with a tusk of an extinct elephant also showing signs of heating.

Besides being the clearest evidence for ancient fire usage at the site, the researchers said that the presence of the heat signature could also be evidence of ancient hominids’ experimentation with different materials.

The team believes that the technique could be employed not only to identify the use of fire, but serve as a window into the origin of its implementation by early humans.”

The study was published in the journal PNAS