by Lillian Pao (’18)

Stone tools have been around for millions of years. It is a technology that has evolved with the hominin phenotype. About three million years ago, flake-making was mastered by the African hominins, followed by handaxes 1.75 million years ago, and custom complex stone reductions by 1.6 million years ago.  Professor Mark W. Moore from the University of New England and a group of researchers identified the changes and development in the models of lower-effort stone flaking.

The experiments included the reduction of 29 large silcrete and mudstone cobbles and 30 medium-sized silcrete flakes. The knapper, a skilled person who shapes the stone, used percussion blows and five solid copper bars to maintain the consistency of the flakes. After the reduction, the team had 1115 cores from the 59 stones. The flakes were then removed and the cores were weighed. Because of the reduction, the mass of the core decreased by 92%-95%. There is a strong correlation between the decrease in core mass and an increase in reduction interval. Reductions require a considerable amount of perceptual-motor and cognitive skills to remove individual flakes; as flake reductions increase, so do the motor and cognitive skills. More skills become necessary to produce a well-desired stone tool. For example, Acheulean handaxes and Levallois Method cores were not possible by knocking off flakes. In fact, handaxes required bifacial flaking, core elongation, and proportions. Likewise, Levallois Method cores included enhancement of the core’s mass and removal of the mass parallel to the bifacial plane.

Since the first stone tool dated 3.3 million years ago, times have changed and technology has produced different conditions and patterns. Moore’s experiment allowed researchers to explore the constraints of stone knapping and random choices to see what products would result and how they compared to the early archaeological record.

References:

1. W. Moore, Y. Perston, Experimental insights into the cognitive significance of early stone tools. Plos One (2016) doi:10.1371/journal.pone.0158803.
2. Image retrieved from: https://museumvictoria.com.au/melbournemuseum/discoverycentre/600-million-years/timeline/quaternary/stone-tools/