Turbulent Era Sparked Leap in Human Behavior, Adaptability 320,000 Years Ago
Published:23 Oct.2020 Source:Smithsonian
For hundreds of thousands of years, early humans in the East African Rift Valley could expect certain things of their environment. Freshwater lakes in the region ensured a reliable source of water, and large grazing herbivores roamed the grasslands. Then, around 400,000 years ago, things changed. The environment became less predictable, and human ancestors faced new sources of instability and uncertainty that challenged their previous long-standing way of life.
The first analysis of a new 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 networks, their landscape was experiencing frequent fluctuations in vegetation and water supply that made resources less reliably available. The findings suggest that instability in their surrounding climate, land and ecosystem was a key driver in the development of new traits and behaviors underpinning human adaptability.