Around 3.3 million years ago our ancestors did something remarkable. Something no other animal has ever done in the wild. They smashed a rock. Whilst that might not sound that impressive; the care and focus that went into this smashing were remarkable. It broke the rock just right; producing the first stone tools.
These first stone tools were crude, but they marked the start of a technological journey that led to whatever electronic device you're reading this on. Could it have all been an accident? After all, these first tools - called the Lomekwian - were found at a site that seems to have been dominated by smashing rocks for another purpose: cracking nuts.
Perhaps those first tools were a happy accident. A bi-product of nut cracking our ancestors recognised as useful.
The first stone tools
The Lomekwian was discovered on a low hill near a lake in Kenya back in 2015. Despite being a relatively new find I already think it's one of the most significant discoveries ever. That's because we almost catch the invention of stone tools in the act.
Their culture is dominated by cracking nuts. However, some of our ancestors have clearly recognised that smashing rocks are good for more than opening nuts. They began using this same process to crack rocks; breaking off sharp flakes. This new development was clearly in its infancy, with many of the new tools showing evidence of mistakes. So, whilst the discovery of the tools themselves was a hugely significant find, the rocks themselves don't seem that impressive.
But don't let that fool you. The "descendants" of these stone tools went on to allow our ancestors to hunt meat, process plants, and they ultimately laid the foundation for modern civilisation. Armed with a more complex version of these tools early modern humans were able to conquer the world; ultimately outcompeting the Neanderthals. These Neanderthals had been able to dominate the world for thousands of years, thanks to their own set of these tools.
All of which can be traced back to these first rocks from a hill in Kenya. Did the manufacturers of the Lomekwian understand the significance of their invention? Was it even deliberate? Some have already pointed out that it was found amongst these rocks being used for another purpose. This purpose produces waste. Might the first tools have been such waste, that some imaginative hominin realised was good for another purpose?
Smashing stuff for science
To investigate this possibility a group of researchers examined whether or not cracking nuts with rocks gave individuals enough skills to make the first stone tools. Which they did by training people to crack nuts, then seeing how many of those skills transferred over to trying to make stone tools.
Turns out the two tasks had very little relationship to each other. This held true for anecdotal observations - with participants who were good at nut-cracking being bad at tool making; and vice versa - but also for a complex anatomical study of the activities. Sensors placed over the hands of the participants examine the forces, pressures, and movements involved in these tasks and found there were many differences between the two. In particular, power is the primary skill involved in nut-cracking; but this is almost useless when making stone tools. It's all about where you hit it. How you held the tool, what you looked for in a rock, and more, also varied between the two tasks.
In other words, the makers of the Lomekwian had to have been over-evolved for nut-cracking in order to make the first stone tools. These objects weren't the accidental by-products of a species suited only for nut smashing. There are many possible reasons for this; none of which can be eliminated at the moment. Maybe they were already using wooden tools (which we have no record of) so had to be good at these other tasks. Maybe being good at those tasks was for something else we don't know about. Or maybe the Lomekwian isn't the oldest set of stone tools out there.
Either way, our ancestors were a lot more competent than they first appear.
Summary
The first stone tools seem to have been invented whilst our ancestors were cracking nuts. However, the ability to crack nuts wasn't enough to allow us to make these tools. We had to have had additional abilities.
References
Bril, B., Parry, R. and Dietrich, G., 2015. How similar are nut-cracking and stone-flaking? A functional approach to percussive technology. Phil. Trans. R. Soc. B, 370(1682), p.20140355.
Harmand, S., Lewis, J. E., Feibel, C. S., Lepre, C. J., Prat, S., Lenoble, A., ... & Roche, H. (2015). 3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya. Nature, 521(7552), 310-315.
