Scarcity of food led early humans to create more durable stone tools

Scientists from the CNRS and the University of Kiel in Germany studied ancient sediments at the Florisbad and Lombard's Drift sites in central South Africa to understand how early Homo sapiens adapted to changing environments.

The researchers found that the region lacked a modern ecological equivalent about 200,000 years ago. Unlike the arid grasslands seen today, the area once hosted plants adapted to temperate conditions and had a more even distribution of rainfall throughout the year.

The team analyzed n-alkanes, which are molecules found in plant waxes preserved in sedimentary beds, to reconstruct these past climates. By using luminescence dating on sand grains, they confirmed that these environmental conditions existed around 200,000 years ago at the Florisbad site. These findings suggest that early humans lived in a landscape that provided different food resources than those available in the modern era.

The study identified a link between these changing environments and the way early humans manufactured stone tools. During periods when food was scarce or difficult to find, people spent more time retouching tools to make them more durable and reusable. When food was plentiful, they used minimally retouched flakes that were faster to produce. This shift shows how early humans modified their subsistence strategies and tool management to survive in fluctuating ecosystems.