Chimp Stone Tool Choices Mirror Ancient Human Ancestors

A new study reveals that modern chimpanzees' selection of stones for cracking nuts mirrors the tool choices of ancient human ancestors. Researchers observed chimps selecting tools based on mechanical properties – harder stones for hammers, softer ones for anvils – rather than appearance. Young chimps also imitated older ones, suggesting learned tool use. This implies shared techniques in stone tool selection between ancient hominins and modern chimpanzees.