Responding to a crisis often brings out the best in people. Certainly, it has in the past, when sudden changes in climate during the Middle Stone Age sparked off surges of cultural evolution and innovation in early modern humans, some 100,000 to 40,000 years ago.
The earliest stone tool-making had developed by at least 2.6 million years ago. However, the pace of innovation really started to accelerate in short, rapid bursts around 100,000 years ago. The use of symbolism and personal adornments became more complex as human culture developed – but what lay behind these periods of rapid development has been harder to establish.
Our study was based on evidence drawn from marine sediment cores – a cross-section through many layers of earth extracted off the South African coast.