By Bruce Bower
Technological revolutions rocked our world long before the information age. Between 80,000 and 60,000 years ago, it was spurts of innovative toolmaking, rather than extreme climate changes, in southern Africa’s Stone Age cultures that heralded a human exodus out of Africa, a new investigation suggests.
Environmental changes in southern Africa, including those brought on by a massive volcanic eruption in Sumatra around 74,000 years ago, played a secondary role at best in instigating ancient cultural advances and intercontinental migrations, say geologist Zenobia Jacobs of the University of Wollongong, Australia, and her colleagues. Other researchers regard ancient climate fluctuations as key motivators of human movement out of Africa.
Jacobs’ team dated sediment at nine sites that have yielded remains of either of two key toolmaking traditions in southern Africa, known as the Still Bay and Howieson’s Poort industries. Still Bay tools were made by striking flakes off prepared pieces of stone for use as lance heads or skinning knives. Howieson’s Poort implements included small blades, scrapers and chisels. Symbolic artifacts and personal ornaments have been found with both tool types.
“Still Bay and Howieson’s Poort industries may be the southern African manifestations of a pan-African technological revolution that catalyzed human migration out of Africa,” Jacobs says.