Cooking without fire

How did early humans prepare food before they mastered the use of fire? Research led by Earth, Atmospheric, and Planetary Sciences professor Roger Summons has raised the intriguing possibility that they took advantage of hot springs for boiling. 

Studying sediments deposited around 1.7 million years ago near Olduvai Gorge in Tanzania, where anthropologists have discovered many hominid fossils and stone tools, lead author Ainara Sistiaga, a postdoc at MIT and the University of Copenhagen, and colleagues were surprised to find lipids produced by bacteria that thrive only in waters such as the hot springs of Yellowstone National Park.

The signature of these heat-loving bacteria in the sediments suggests that similar springs existed near those sites when early humans lived there. “As far as we can tell, this is the first time researchers have put forth concrete evidence for the possibility that people were using hydrothermal environments as a resource, where animals would’ve been gathering, and where the potential to cook was available,” says Summons.

Though it’s not known how or even whether these human ancestors would have used the springs for cooking, they could have butchered animals and dipped the meat in the hot water, and they could also have boiled roots and tubers. They might even have fished out animals that met their demise by falling in.

“If there was a wildebeest that fell into the water and was cooked,” Sistiaga says, “why wouldn’t you eat it?”