A new study involving researchers from the University of London, Los Angeles (UCL) and Spain's National Research Council (CSIC) suggests that our ancestors developed advanced abstract reasoning abilities a million years earlier than previously thought. For the study, published in the journal Nature, researchers studied a collection of 27 fossilized bone tools that were hand tools made by early humans 1.5 million years ago.
The discovery represents the oldest known collection of systematically crafted bone tools, pushing back the timeline of such tool making by a million years.
Early human ancestors known as great apes (human ancestors capable of walking upright) had been making tools from stone to some extent at least a million years ago, but until about 500,000 years ago, tool making from bone was rare.
The great apes shaped the recently discovered bone tools in a similar way to how they made tools from stone, by chipping away small flakes of stone to create sharp edges - a process known as "tapping."
Impact on early human intelligence
This transfer of technology from one medium to another shows that the humans who made the bone tools had a high level of awareness of tool making and that they could adapt their techniques to different materials, which was a major intellectual leap. This may indicate that the cognitive abilities and brain development of human ancestors at that time were higher than scientists thought.
Co-author Dr Renata F. Peters (UCL Archeology) said: "These tools show that their creators carefully worked these bones, shaving thin slices to create useful shapes. We are delighted to have discovered these bone tools at such an early period. It means that human ancestors were able to transfer skills from stone to bone, with a level of cognitive sophistication we have not seen elsewhere for a million years."
Lead author Dr Ignacio de la Torre, CSIC - the Spanish National Research Council, added: "This discovery leads us to believe that early humans greatly expanded their technological options, which had previously been limited to making stone tools, to now allowing them to incorporate new raw materials into the range of potential artefacts."
"At the same time, this expansion of technological potential demonstrates advances in the cognitive abilities and psychological structures of these humans, who knew how to incorporate technological innovations into the production of skeletons by adapting their knowledge of stone tool processing."
The tools were discovered in Tanzania's Olduvai Gorge, a site long known for important archaeological discoveries that have shed light on human origins.
Researchers found 27 bones that were shaped into tools at the site. Most of these bones are from large mammals, mainly elephants and hippopotamuses. These tools were made entirely from animal limb bones, as these are the densest and strongest.
These tools have their origins in prehistoric times, when early humanoid cultures were undergoing the first ever technological transformation.
The earliest stone tools come from the "Oldowan" era, which dates from about 2.7 million to 1.5 million years ago. It uses a simple method to make stone tools, which is to use a hammer to knock off one or several stone flakes from the stone core.
The bone tools reported in this study were used by ancient human ancestors as they entered the "Acheulean" era, which dates back as far as 1.7 million years ago. Acheulean technology was characterized by the use of more complex hand axes that were carefully shaped by hammering - allowing for a more standardized way to produce tools. More advanced technology was inherited and used on bone tools never seen in the fossil record a million years ago.
Prior to this discovery, bones shaped into tools had only been found sporadically in the fossil record in a few isolated instances, and there had never been any suggestion that human ancestors had systematically made such tools.
While the exact purpose of these tools is unclear, their overall shape, size, and sharp edges suggest they were likely used to process animal carcasses for food.
It's unclear which human ancestor made these tools. No ape remains were found during the collection of bone tools, but our human ancestors erectus and another type of ape known as hominin are known to have been residents of the area at the time.
Because the discovery of these tools was unexpected, the researchers hope that their findings will prompt archaeologists to re-examine bone tools found around the world in case other evidence of bone tools has been missed.
Compiled from /ScitechDaily