THE quest for fire -- and evidence of our human ancestors' use of it -- has led Toronto researchers into a South African cave where they have uncovered traces of ash, animal bones and stone tools dating back a million years.
The discovery pushes the date for a crucial turning point in human evolution -- the ability to control and use fire -- back by 300,000 years.
It is the "earliest unambiguous evidence" that early humans used fire as part of their way of life, reports an international team co-led by Michael Chazan at the University of Toronto.
"We are finding material that had to have burned in the cave," Chazan said in an interview Monday. "That we can say with as close to absolute certainty as you get in science."
The evidence, detailed in the Proceedings of the National Academy of Sciences, comes from the massive Wonderwerk Cave near the edge of the Kalahari Desert that a million years ago was used by early humans known as Homo erectus.
Homo erectus had smaller brains than modern humans and it is not known whether they were more like modern hunter-gatherers or more like baboons and chimpanzees, Chazan says. "That is something we still really struggle to answer."
But Homo erectus was smart enough to make crude tools and capture deer-size mammals and tortoises, which the study shows were hauled back to the cave and thrown on fires.
Chazan says Homo erectus may have collected embers from natural fires caused by lightning strikes, which can be seen for long distances on the African plains, or perhaps they had learned to make and preserve fire.
"That's to me the most interesting question," says Chazan. "Were they capable of making fire, were they capable of preserving fire for long periods of time?"
-- Postmedia News