Surprising leap in ancient human technology tied to environmental upheaval

[Judi Lynn]

Sediment core evidence reveals the critical factors that may have given rise to strikingly complex behaviors some 320,000 years ago, around the time the first members of our species appeared.

5 MINUTE READ
BY MAYA WEI-HAAS
PUBLISHED OCTOBER 21, 2020

For 700,000 years, our species’ ancient relatives in East Africa led rather stable lives, relying on an enduring set of skills and survival strategies. They made large, simple hand axes from nearby stones, perhaps using them to slice up prey, cut down branches, or dig for tubers.

But by 320,000 years ago—around the same age as the earliest fossil evidence of Homo sapiens—these early humans drastically changed their ways. They began crafting smaller, more nimble points that could fly through the air as projectiles, some made from obsidian gathered from many miles away. They collected red and black pigments—substances later humans frequently used in symbolic ways such as cave painting.

Now a new study in Science Advances suggests that one major reason behind this sudden shift in behavior lies underground: tectonic activity that fragmented the landscape.

Scientists have long pointed to changes in climate, such as the onset of wet or dry periods, as the key driving force behind the adaptation of our early ancestors. The new study puts this idea to the test by examining a detailed record of environmental changes over almost a million years, etched into a 456-foot-long core of sediment layers extracted from an ancient lake.

The geologic record of the lake reveals a cascade of ecologic change around the same time new technologies appear in the archaeological record. A variable climate and a shifting landscape caused once stable food and water resources to ebb and flow, likely throwing the lives of early humans in East Africa into turmoil and forcing them to innovate and adapt.

More:
https://www.nationalgeographic.com/science/2020/10/surprising-leap-in-ancient-human-technology-tied-to-environment/#close