The stone age was a milestone in human history, albeit a long one, marking the period where we started using stone tools, building homes and shelters, wearing clothes and generally developing 'humanity' as we know it today. Now the chimps are catching up.
Chimpanzees are our closest living relative, yet for so long the common understanding has been that the stone age is a uniquely human development.
But that is not so: chimps in West Africa routinely use crude stone 'hammers' as tools for cracking nuts, in a way that appears to be handed down through the generations to form a culture of tool use.
This isn't a new development either. The new field of 'primate archaeology' is tracing the origins of these tools back through millennia. Evidence of chimp-wielded tools found by these archaeologists goes back at least 4300 years, with unrecorded use probably stretching far longer than that.
Chimp stone tool use is distinct from that of ancient humans - both in the way we use them, and in the tools themselves. For one, chimps reportedly select stones over a kilo to use for their tools, while humans prefer smaller ones under that weight.
Now this doesn't mean chimps are about to start catching up to us any time soon. Human ancestors were making these kinds of stone tools around 3.3 million years ago, meaning either chimps have a long way to go yet, or they simply don't have the brain capacity to make the leap from selecting tools to creating tools.
Either way, it seems we're not as alone on this planet as we like to think, and perhaps Planet Of The Apes isn't as far fetched as we think it is...
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