Human’s use of stone blades critical step in evolution

APE-LIKE humans were cutting up meat with stone blades more than three million years ago, long before the earliest previous evidence of tool use, scientists revealed.

The discovery of fossil animal bones bearing butchery marks pushes back the known history of tools by almost a million years.

The creatures who wielded the implements pre-date the evolution of the Homo primate family to which modern humans belong.

Previously, it was believed intelligent tool use only started with the emergence of the Homo genus.

Now it is known that a much more primitive ancestor, Australopithecus – which resembled an upright walking ape – understood how to use blade-like stones to strip meat off bones.

Whether it manufactured the tools or used conveniently ready-made stones with sharp edges is not yet known.

Dr Zeresenay Alemseged, from the California Academy of Sciences in the US, who led the researchers responsible for the find, said: “This discovery dramatically shifts the known timeframe of a game-changing behaviour for our ancestors.

“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 that eventually enabled such advanced technologies as aeroplanes, MRI (body scanning) machines, and iPhones.”

“This find pushes the evidence for tool use and meat eating in our family back by nearly a million years.

“These developments had a huge impact on the story of humanity.”

Scavenging carcasses with stone tools would have put the early humans in direct and risky competition with other carnivores, he said.

This in turn would have spurred on human mental development by making it necessary to engage in a high level of teamwork.

The discovery is reported in the journal Nature.

Working at Dikika in the Afar region of Ethiopia – known as the “cradle” of humankind, where our ancestors first evolved – Dr Alemseged’s team found fossil animal bones bearing marks left by butchery.

The bones were around 3.4 million years old and found just 200 yards away from a site where the same scientists uncovered an Australopithecus skeleton known as “Selam” in 2000.

Selam has been dubbed “Lucy’s daughter” after the most famous human ancestor, whose remains were unearthed in the same region of Ethiopia in 1974.

Both Selam and Lucy belonged to the species Australopithec us afarensis. Their fossils date back to almost exactly the same time as the animal bones bearing the cut marks.

Australopithecines stood no more than around four feet tall and had brains about a third of the size of a modern human’s. Although ape-like, with protruding jaws and brow ridges, they had a pelvis structure and feet similar to those of humans living today.