Jacobs, Zenobia; Roberts, Richard G.; Galbraith, Rex F.; Deacon,
Hilary J.; Grun, Rainer; Mackay, Alex; Mitchell, Peter;
Vogelsang, Ralf; and Wadley, Lyn, 2008, Ages for the middle
stone age of Southern Africa: implications for human behavior
and dispersal, Science, 322, 733-735. The expansion of modern
human populations in Africa 80,000 to 60,000 years ago and their
initial exodus out of Africa have been tentatively linked to two
phases of technological and behavioral innovation within the
Middle Stone Age of southern Africa - the Still Bay and
Howieson's Poort industries - that are associated with early
evidence for symbols and personal ornaments. Establishing the
correct sequence of events, however, has been hampered by
inadequate chronologies. We report ages for nine sites from
varied climatic and ecological zones across southern Africa that
show that both industries were short-lived (5000 years or less),
separated by about 7000 years, and coeval with genetic estimates
of population expansion and exit tim