Chimpanzees can fashion sandals out of leaves to walk across thorny ground It is hard to imagine life without tools—finding food with our bare hands, eating it raw with our teeth, seeking a cave or a tree for shelter. In fact, our reliance on tools is reflected in our brains and bodies. The areas of our brains responsible for things like controlling our hands are enlarged compared with other primates.
Our hands themselves are different, with proportionately longer thumbs and other anatomic changes that allow us to touch our fingertips and hold tools with more skill.
The dawn of tool use was a crucial turning point in human history: It let our ancestors take control of their lives by finding food in places that were off-limits to their ancestors. But scientists still have hardly any clues to how that evolutionary transition took place. The most reliable record of our technological history comes from the tools themselves. The oldest known hominid tools date back 2.3 million years, to a collection of chipped rocks in Ethiopia. They don’t look like much, but with them hominids could butcher an elephant or crack open a wildebeest’s bones and suck out the marrow.
Mentally, they’re also a big accomplishment: They require a brain capable of looking at an untouched rock and seeing a tool hiding within it. In recent years, however, some hints have emerged that human technology may have roots reaching back millions of years further into the past. For one thing, chimpanzees and other apes have proved surprisingly gifted at making tools. In order to walk across thorn-covered ground, chimpanzees can fashion sandals out of leaves. In order to eat termites, they can strip sticks to create fishing tools. Unfortunately, a leaf-sandal doesn’t leave a fossil. But some researchers believe that the hands of hominids may shed some light on the mystery of tools.
For example, Lucy and her A. afarensis fellows lived a million years before the oldest tools. Despite having curved, chimplike fingers, this hominid also had an elongated thumb that could make contact with its fingertips.
“”There’s nothing to say that these creatures couldn’t make crude stone tools,”” says Bernard Wood of George Washington University. It’s possible that hominids had already become skilled with wood and other materials 3.5 million years ago, paving the way to mental breakthroughs for making stone tools.
As intriguing as this hypothesis may be, however, many researchers think there’s not enough evidence to say anything definitive about the evolution of tool use. Tim White, a paleoanthropologist at the University of California at Berkeley, says any speculations “”would be strictly X-Files.”””