A mixed team of archaeologists and scientists at the Indiana University (USA) have been throwing some very sophisticated analytical study at a group of stones, collectively dating from 1.8 million to 70,000 years old, which were found at an archaeological site in South Africa, known as the Cave of Hearths.
     Originally it was conjectured that these stones, roughly the size of a tennis ball, were used to shape or grind other objects. Now, the new theory revolves around them being used as a thrown weapon. Using computational tools and theoretical modelling the team has concluded that, based on what is known about the physical strength of humans at that time, the optimal distance at which these stones could be accurately thrown, to hit a specific target with enough power to cause damage, ranged between 20 and 30 metres, well within biomechanical and visual properties (to gauge distance).
     Whilst this research is conjecture, albeit based on strong models, Professor Geoffrey Bingham, of the Indiana University Bloomington College of Arts and Sciences, Department of Psychological and Brain Science, is very upbeat about their findings, "Our study suggests that the throwing of stones played a key role in the evolution of hunting. We don't think that throwing is the sole, or even primary function of these spheroids, but these results show that this function is an option that warrants reconsidering as a potential use for this long-lived, multipurpose tool".

Edited from EurekAlert, PhysOrg (18 August 2016)