Primitive stone tools may just be monkey business

STONE shards which were thought to be early tools made by our human ancestors can be created accidentally by monkeys, scientists have discovered.

Sharp flakes, dating back 3.3 million years, have been found near the remains of ancient hominids, leading experts to believe they had been intentionally created by our forebears.

But a study of long-tailed macaques in the Phang Nga National Park in Thailand has showed that when they use rocks to crack open nuts, pieces of stone can shear off, leaving shards identical to those seen at hominid sites.

It raises the question of whether early hominids were making the tools consciously, or if they were a byproduct of activities such as nut cracking.

Some ancient stone tool finds, which are not directly linked to hominid [ape] remains, may even have been made by monkeys, the research suggests.

“The ability to intentionally make sharp stone flakes is seen as a crucial point in the evolution of hominins, [humans and bipedal ancestors],” said lead author Tomos Proffitt, a researcher at the Max Planck Institute for Evolutionary Anthropology (MPI EVA).

“Our study shows that stone tool production is not unique to humans and our ancestors.”

Lydia Luncz, senior author of the study and head of the technological primates research group at the MPI EVA, said: “Cracking nuts using stone hammers and anvils, similar to what some primates do today is a possible precursor to intentional stone tool production.”

“This study opens the door to being able to identify such an archaeological signature in the future and shows how living primates can help researchers investigate the origin and evolution of tool use in our own lineage”

The research was published in the journal Science Advances.