Early stone tools, and in particular sharp stone tools, arguably represent one of the most important technological milestones in human evolution. The production and use of sharp stone tools significantly widened the ecological niche of our ancestors, allowing them to exploit novel food resources. However, despite their importance, it is still unclear how these early lithic technologies emerged and which behaviours served as stepping-stones for the development of systematic lithic production in our lineage. One approach to answer this question is to collect comparative data on the stone tool making and using abilities of our closest living relatives, the great apes, to reconstruct the potential stone-related behaviours of early hominins. To this end, we tested both the individual and the social learning abilities of five orangutans to make and use stone tools. Although the orangutans did not make sharp stone tools initially, three individuals spontaneously engaged in lithic percussion,
Discussions of heat treatment in the southern African Middle Stone Age often focus on the importance of this innovation to the development of complex technologies and the evolution of modern human cognition. Debates regarding the context of silcrete heat treatment typically include the amount of time and resource investment needed, and when the earliest occurrences of heat treatment appear in the archaeological record. However, silcrete is a heterogeneous material and the potential effects of this heterogeneity on the thermal transformations that occur during heat treatment are not well established. We undertook a series of controlled experiments using direct transmission near-infrared spectroscopy on South African silcretes from multiple sources heated to a range of maximum temperatures to examine the degree of heterogeneity in starting structural content and the evolution of thermal transformations. We found that material source is an important determinant of starting concentrations