The headline should be - rethinking some aspects of human evolution. At https://cosmosmagazine.com/palaeontology/accidental-tool-makers ... and I suppose the problem can be laid at Uniformitarian principles, progress in small steps, from primitive thinking to sophisticated behaviour. Palaeoanthropologists have long cast their eye upon stone tools as a means of evaluating human progress (on the evolutionary scale that primitive is almost always older than the better examples of manufacture). This is especially true when it comes to flakes and it is a given that flakes were knapped in order to produce a nice cutting edge. Secondary flaking was used to gain an even better edge, or to resharpen the original tool (and so on). It sounds sensible (why would primitive humans produce flaked tools). The answer might be that they also required a cutting edge - particularly when butchering a recent kill from a hunting expedition. Therefore, there has always been a bit of conflict in archaeological circles - especially when lots of flakes are produced when knapping. However, the uncertainty is even greater now as heaps of flakes may themselves not have a connection with human activity at all. Potentially, this is a disaster for archaeologists we are told - but not really. Knapping was done by modern humans and one can see how useful flakes and useless flakes are produced simply by some guy smacking a piece of flint or chert with the intention of achieving a desired object - a stone axe, perhaps, or a sharp cutting tool.
Recent research published in Nature (March 2017) by scientists based at Oxford University show that capuchin monkeys regularly produce sharp edged flakes indistinguishable from those made by early hominims. Capuchins live in South America and the flakes are produced by accident, from when the monkeys smash rocks together. These flakes can not be described as tools as they are discarded by the monkeys. All they want to do is get inside the stone. The flakes are of no interest to them.
Chimpanzees use tools to crack nuts open or they manoeuvre long stems to fish for termites. Other animals, birds, snails, octopus, and even some insects all turn out to be tool users. For example, wasps use pebbles to hammer down soil to hold their burrows. The Leakey's famously found flakes associated with Homo habilus in East Africa - and they purportedly lived 2 million years ago. The Leakey's work was at the borderline - and the flakes played a prominent role. The theory was that the hominid got hold of one piece of rock and bashed it with another piece in order to strike off a wedge (a sharp edged flake) which enabled him to cut up and prepare meat. Hence, it thus became the norm in anthropological circles that making a flake required sophisticated mental abilities (such as the ability to plan and execute). It also involved hand an eye co-ordination.Now it seems some flakes will come under critical scrutiny as they may not be all they are cracked up to be. Capuchin monkeys pound rocks together to break them open to lick the powdered quartz. The pounding causes many flakes to go flying this way and that - and a heap of flakes can be produced by this method, on the same spot. Hence, when ancient flakes are found we are now let wondering - human or ape?