If nothing else, the timing is right, according to a new study of volcanoes in the East African Rift.
By Nathan Collins
(Photo: Hector Guerrero/AFP/Getty Images)
Human beings have managed to adapt to a startlingly wide range of natural environments, whether hot, cold, wet, or dry. Maybe we’ve always had that survival capability in us: According to a new study published today in Nature Communications, volcanoes were especially active around the time and place the Homo sapiens was born.
It’s wholly unsurprising that volcanoes might have played a role in the lives of early humans. Our first ancestors grew up in what we now call the East African Rift, a line along which the African continent is slowly splitting in two. Many of us already know of another rift which humans inhabit—the Mid-Atlantic Rift splits Iceland in two, producing some spectacular volcanic displays in the process. What’s more, such eruptions can profoundly reshape the environment, changing plant and animal life for years to come, and perhaps helping to shape human evolution.
Of course, that’s all a bit speculative, and before we can get to the matter of whether volcanic activity helped make our species what it is today, we have to figure out whether humans even lived near active volcanoes—more specifically, whether volcanoes along the East African Rift were active around the time modern humans came into being.
It’s wholly unsurprising that volcanoes might have played a role in the lives of early humans.
To answer that question, William Hutchison, a graduate student in earth science at the University of Oxford, and his colleagues turned their attention to a roughly 120-mile long section of the Rift, including Ethiopia’s Aluto and Corbetti calderas. There, the team mapped out a variety of volcanic rock formations and determined their age using methods similar to carbon dating. Aluto, they found, likely erupted in a series of explosions around 310 thousand years ago, creating a low, wide “shield” around 15 kilometers across that eventually collapsed, forming the large caldera there today. Corbetti followed a similar pattern around 180 thousand years ago.
Data from previous expeditions in the area suggest other volcanoes erupted following similar patterns between roughly 320 and 260 thousand years ago, the team notes, suggesting there may have been a “major pulse of volcanic activity” just as humans were becoming, well, human.
The results do not address whether or how the course of human evolution would have changed in response to volcanic activity, but, given the power of volcanoes to shape their environs, the authors suggest it’s worth exploring further.
“To fully understand the links between environmental changes and human evolution, volcanic and tectonic processes must be appreciated alongside the palaeoclimate evidence,” Hutchison and his colleagues write.