Prehistory's Mysteries: Like iPods in Ancient Rome

Image Source: National Geographic.

National Geographic reports that prehistoric stone spear tips were found in South Africa at a Homo heidelbergensis site in 2012. The catch is that the spear tips date to 500,000 years ago, which is 100,000 to 250,000 years earlier than the accepted date for the invention of spear tips. Paleoanthropologist John Shea, who was not part of the study, told NatGeo that if the dating is accurate, it would be "like finding an iPod in a Roman Empire site." The find implies that this primitive hominid used complex language and complex tools. But researchers wonder why related complex artifacts are not evident alongside these sophisticated weapons:

Some of our early human ancestors may have been smarter, and deadlier, than we thought, according to a new study of what may be Earth's oldest stone spear points. If the dating is correct, it suggests our evolutionary forebears mastered the art of the stone-tipped spear half a million years ago—some 250,000 years earlier than previously thought. ... Until now ... there's been no evidence H. heidelbergensis had the know-how to put the two together.

To fasten a handle to a blade—a technique called hafting—a prehistoric hunter likely would have had to procure a stone blade, a wooden shaft, twine woven from plants or animal sinew, and glue made from tree resin. The glue itself may have required a mastery of fire, to liquefy the resin, said Shea, of New York's Stony Brook University. ...

Hafting would have been worth the work, because once you add a stone blade, a spear is "going to cause a lot more damage, create more bleeding, and cause the animal to die quicker," said University of Toronto anthropologist Jayne Wilkins, lead author of the new spear-tip study, released Thursday by the journal Science.

By allowing more efficient hunting, Wilkins explained, the spear "means more reliable and regular access to meat." And scientists agree that more meat in the diet meant increased human brain size. That's not just an increase in brain tissue, she added. The increase in size hints at intellectual expansion. The hafting process requires forethought. "You have to plan days in advance before actually being able to use your weapons to hunt," she said. And you'd want to teach your comrades to do the same, presumably by talking.

For Stony Brook's Shea, there's "no question" that hafting involved speech. "It would probably not be something that could be taught by imitation. This is a technology that is so complex that it absolutely, positively requires language."

The idea that H. heidelbergensis may have had language may not be especially shocking, given that the species is theorized to be the last known common ancestor of both Neanderthals and our species, Homo sapiens.

"We have language, and Neanderthals likely had language ... so it stands to reason that our last common ancestor had linguistic abilities too," Shea said. (See "Neanderthals Had Same 'Language Gene' as Modern Humans.") ...

he age of the spear points remains a matter of debate. If they are really a half million years old, why haven't we found them at later sites? The gap—between 500,000 and 250,000 years ago, is richly represented by archaeology, Shea said. But we haven't found stone spear tips. Why not?

It's possible, Shea said, that the technology was simply lost, only to be invented all over again thousands of years later. But "I don't think it's likely this is something that people invented and then abandoned," he said. "You wouldn't expect that kind of complexity to vanish completely."

There's another mystery, Shea explained. It's not just stone spear points that seem to be missing from other H. heidelbergensis sites. "If they could make glue, they should have been able to make other complex substances and artifacts, even ceramics," he said. But there aren't any. And, he added, if H. heidelbergensis could put stone tips on handles, you ought to see other tools, like axes, with stone tips and handles.

Homo heidelbergensis. Image Source: John Gurche, artist / Chip Clark, photographer / Smithsonian.