The first evidence of early humans using fire dates back to more than a million years, but the practice did not become routine until about 650,000 years later, the latest research indicates. Reuters

New research lends credence to the theory that humans’ early ancestors were using fire long before Homo sapiens stepped on the scene 200,000 years ago, according to a study published this month in the Journal of Human Evolution. Scientists have found evidence of controlled fire use inside an ancient cave in Israel that was home to several lineages of prehistoric hominins, the predecessors of modern humans. Artifacts discovered at the site, located in the Nahal Me'arot Nature Reserve in northern Israel, suggest that fire use became routine among hominins around 350,000 years ago.

The site, known as Tabun Cave, “is unique in that it’s a site with a very long sequence” of early human occupancy, Ron Shimelmitz, an archaeologist at the University of Haifa and a co-author of the new study, told Science magazine. “We could examine step by step how the use of fire changed in the cave.”

Evidence of fire use at Tabun came from the discovery of Stone Age flint tools, which were used for scraping and cutting meat. The Stone Age spanned from about 3.4 million years ago to about 6000 B.C. and was marked by widespread use of stone tools, the earliest form of manmade technology. Researchers looked at the oldest layers of cave sediment, about 16 meters (52 feet) below the cave floor. They discovered that flint tools excavated from deposit layers older than 350,000 years were mostly unexposed to fire. Flint tools dated to after 350,000 years ago, however, had telltale signs of fire contact – discoloring, cracking and fragmenting, according to Science.

That distinction between flint tools not exposed to fire and those that were represents the transition from sporadic to regular fire use among hominins, according to paleontologists in the cave’s excavation. “While hominins may have used fire occasionally, perhaps opportunistically, for some million years, we argue here that it only became a consistent element in behavioral adaptations during the second part of the Middle Pleistocene,” between 781,000 and 126,000 years ago, researchers said in their report.

The ability to control and manipulate fire has long been credited with the rise of the human species. Without cooked food, many anthropologists believe the human brain would not have developed into what it is today, according to Smithsonian. “The unprecedented increase in brain size that hominids embarked on around 1.8 million years ago had to be paid for with added calories either taken in or diverted from some other function in the body,” Jerry Adler of Smithsonian magazine wrote last year. “Many anthropologists think the key breakthrough was adding meat to the diet.” Humans get about 30 percent more energy from cooked food than raw food, an important distinction that allowed early humans to fuel a growing brain.

Previous research has shown that the first instance of fire use occurred around 1.9 million years ago, around the time humans’ ancestors began to develop bigger noggins.