At a rock shelter on a coastal cliff in South Africa, scientists have found an abundance of advanced stone hunting tools with a tale to tell of the evolving mind of early modern humans at least 71,000 years ago.
The discovery, reported in the current issue of the journal Nature, lends weight to the hypothesis that not only did anatomically modern Homo sapiens emerge in Africa but also, to a previously unsuspected extent, their cognitive capacity for abstract and creative thought and the conception of increasingly complex technologies associated with modern human behavior.
The report describes the stone tools as microliths, thin blades about only an inch long that could be affixed to wood or bone. These tipped projectiles were either arrows propelled by bows or, more likely, spears launched by atlatls, wooden extensions of the throwing arm that act as a lever, imparting greater speeds and distances to the weapon. This technology, the researchers said, may have been pivotal to the success of Homo sapiens as humans left Africa and entered Eurasia some 50,000 years ago, encountering Neanderthals who were limited to hand-thrown spears.
The new evidence appeared to answer some critics who have contended that previous findings of early modern human behavior in Africa have been spotty and short-lived
— a “flickering” pattern of experimentation with little or no continuity over time and across regions. The rock shelter excavations at Pinnacle Point, near Mossel Bay, east of Cape Town, show that this micro-blade technology continued over 11,000 years, until 60,000 years ago. The report says the technology was also “typically coupled to heat treatment” processes in shaping sharp and durable blades that persisted for nearly 100,000 years.