Scientists have uncovered compelling new evidence suggesting early human ancestors were using fire deep within South Africa's Wonderwerk Cave as far back as 1.8 million years ago. This discovery significantly pushes back the timeline for one of the earliest known instances of fire use linked to hominins and offers fresh insights into how our ancient relatives first learned to control this essential element.
Using an innovative technique to detect burning in fossilized bones, researchers found repeated signs of fire well inside the cave. Crucially, these traces were located too far from the cave entrance to be attributed to natural wildfires, strongly indicating that early humans deliberately brought fire into the cave and maintained it.
This groundbreaking research builds upon previous findings at Wonderwerk Cave, which in 2012 revealed evidence of fire use around 1 million years ago, previously considered the oldest known example of intentional fire use globally. The latest analysis, published in PLOS One, extends this timeline to between 1.07 and 1.79 million years ago, solidifying Wonderwerk Cave's status as one of the oldest known sites associated with hominin fire use.
The study introduces a novel method for identifying burned bone by analyzing its light-emitting properties when exposed to specific light wavelengths. This luminescence technique, combined with chemical analysis, allows for high-confidence identification of burned animal bones. Researchers applied this non-destructive approach to hundreds of tiny fossil bones left by owls, which provided an independent record of past events within the cave.
The evidence points to fire being present approximately 30 meters inside the cave, in layers associated with early Acheulean artifacts, likely used by Homo erectus. The findings suggest these early humans were collecting fire from natural sources, like lightning strikes, rather than creating it themselves. Transporting fire into the cave and keeping it burning, even for a limited time, represents a major behavioral leap, enabling warmth, protection, and potentially early forms of cooking.
"These discoveries show that early humans were not simply passive observers of natural fires," explained Dr. Liora Kolska Horwitz, co-director of the Wonderwerk Cave project. "They were actively engaging with fire and incorporating it into their lives." This new technique promises to unlock further secrets about the origins and evolution of one of humanity's most transformative technologies.
