From stones to sketches: investigating tracing behaviours in Japanese macaques.

The use of complex technologies by humans (Homo sapiens) and their ancestors is a key feature of our evolution, marked by the appearance of stone tools 3.3-million years ago. These technologies reflect cognitive complexity and an advanced understanding of materials and mechanics. Studying current primates, especially those that use stones, offers insights into the evolution of human behaviours. In particular, stone manipulation by macaques suggests that some complex behaviours in humans, such as creation of cutting and biface tools, could have emerged unintentionally. The Japanese macaques (Macaca fuscata) of Shodoshima were observed to leave marks on the ground with stones and chalk. By analysing this manipulation of stones, I suggest that drawing in humans could have appeared unintentionally; these unintentional origins of mark-making behaviours may represent early precursors to human drawing.