Our ancestors were hunting with stone-tipped spears around 200,000 years earlier than previously thought - meaning the technology must have been developed by Homo heidelbergensis, the last common ancestor of both modern humans and Neanderthals.
     The use of spears for hunting has been dated back to at least 600,000 years ago from sites in Germany, but the oldest spears are nothing more than sharpened sticks. The evidence for stone-tipped spears until now has been no more than 300,000 years old, from triangular stone tips found all over Africa, Europe and western Asia. "They're associated in Europe and Asia with Neanderthals and in Africa with humans and our nearest ancestors," said Jayne Wilkins, an archaeologist at the University of Toronto who took part in the latest research.
     To find out if any stone tips were being used on spears any earlier than that, Wilkins examined sharp stones found at a site called Kathu Pan, in the Northern Cape region of South Africa. The sediments in which these tips had been found had been previously dated to 500,000 years old.
     Wilkins put the stones under a microscope to look for the tell-tale damage caused when they are used on spears. "We know from experimental studies that, when a point is used as a spear tip, the concentration of damage is greater at the tip of the point than along the edges," she said. "That's the same pattern we saw in the Kathu Pan point."

Edited from EurekAlert, and The Guardian (15 November 2012)