A University of Toronto-led team of anthropologists has found evidence that human ancestors used stone-tipped weapons for hunting animals 500,000 years ago — 200,000 years earlier than previously thought.
"This changes the way we think about early human adaptations and capacities before the origin of our own species," says Jayne Wilkins, a PhD candidate in the department of anthropology at the University of Toronto and lead author of a new study in Science magazine.
"Although both Neanderthals and humans used stone-tipped spears, this is the first evidence that the technology originated prior to or near the divergence of these two species."
Attaching stone points to spears — known as "hafting" — was an important advance in hunting weaponry for early humans, says Wilkins. Hafted tools require more effort and foreplanning to manufacture, but a sharp stone point on the end of a spear can increase its killing power.
Hafted spear tips are common in Stone Age archaeological sites beginning about 300,000 years ago. This new study shows that they were also used in the early Middle Pleistocene, a period associated with the Homo heidelbergensis species, who were the last common ancestor of Neanderthals and modern humans.
"It explains why we share some traits with the Neanderthals, we share a common ancestor," said Wilkins in an interview that airs on Quirks & Quarks on Saturday.
"This common ancestor was an effective hunter who made hafted spears. It also tells us that our history as effective hunters and our adaptation as effective hunters is deep-rooted and has a long story. The traits that make us human, essentially, have been accumulating over a very long time."
Wilkins and her colleagues from Arizona State University and the University of Cape Town examined 500,000-year-old stone points from the South African archaeological site of Kathu Pan 1 and determined that they had functioned as spear tips.
Point function was determined by comparing wear on the ancient points to damage inflicted on modern experimental points used to spear a springbok carcass target with a calibrated crossbow. The stone points exhibit certain types of breaks that occur more commonly when they are used as tip spears, compared to other uses.
"The archaeological points have damage that is very similar to replica spear points used in our spearing experiment," Wilkins says. "This type of damage is not easily created through other processes."
The points were recovered during the early 1980s during excavations by Peter Beaumont of the McGregor Museum in South Africa.