Evidence from ancient bones found in Ethiopia suggest that human ancestors were using stone tools to carve meat a million years earlier than previously thought, an international team of researchers said Wednesday.
Fossilized bones unearthed in the Afar region of Ethiopia by a team from the California Academy of Sciences reveal grooves and cut marks where tools were used to cut meat away from bones, or used to break bones to extract marrow, they reported in the journal Nature.
The tool-marked bones date to about 3.4 million years ago. Before the find, the oldest evidence of butchering with stone tools dated to about 2.5 million years ago.
"This discovery dramatically shifts the known time frame of a game-changing behavior for our ancestors," Dr. Zeresenay Alemseged, who led the team, said in a statement.
"Tool use fundamentally altered the way our early ancestors interacted with nature, allowing them to eat new types of food and exploit new territories. It also led to tool making -- a critical step in our evolutionary path," he said.
The butchered bones were found near the site where Alemseged's team in 2000 discovered "Selam," a pre-human girl who lived about 3.3 million years ago.
"After a decade of studying Selam's remains and searching for additional clues about her life, we can now add a significant new detail to her story," Alemseged said.
He said it is likely that Selam carried stone shards and helped her family butcher animal remains.
"This type of behavior sent us down a path that later would lead to two of the defining features of our species -- carnivory and tool manufacture and use," Dr. Shannon McPherron, archeologist with the Dikika Research Project in Ethiopia and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said in a statement.