The first analysis of a sedimentary drill core representing 1 million years of environmental history in the East African Rift Valley shows that at the same time early humans were abandoning old tools in favor of more sophisticated technology and broadening their trade, their landscape was experiencing frequent fluctuations in vegetation and water supply that made resources less reliably available. The findings suggest that instability in their landscape was a key driver of human adaptability.
Source: Turbulent era sparked leap in human behavior, adaptability 320,000 years ago — ScienceDaily
Darwiniana 