Paris---Chimpanzees and humans share some of the basic brain skills needed for cooking, a finding that may explain a turning point in the story of mankind, a study said Wednesday.
Experiments at a chimp sanctuary suggest a common ancestor imparted these cognitive abilities to apes and humans alike, it said.
If so, it sheds light on how we came to cook -- an activity so banal that we have lost sight of its importance.
Using heat to break down tough fibres and starch, making meat and tubers easier to digest, broadened the diet of our hominid ancestors.
It provided the calorie boost that in turn led to the evolution of bigger, energy-hungry brains.
But when and how did humans acquire this skill?
A pair of scientists from Harvard and Yale believe the clue lies in Pan troglodytes -- chimpanzees, our closest living relative since our common ancestor split into ape and hominid lineages some 13 million years ago.
Many capacities for cooking "are thought to be uniquely human," said Alexandra Rosati, a Yale psychologist. "That's why we wanted to study this in chimpanzees."
Rosati and Felix Warneken of Harvard reported on experiments with two dozen wild-born chimps at the Tchimpounga Sanctuary in the Republic of Congo.
Their work appears in the journal Proceedings B of the Royal Society, Britain's de-facto academy of sciences.
In the first test, scientists placed a slice of sweet potato in a hot pan, without butter or oil, and offered it to the chimps alongside a raw sample.
The chimps vastly preferred cooked potato, they established.
The next step was to probe whether the animals understood how the food transformation worked.
For this, the team used a fake "cooking device" -- a plastic container with a false bottom concealing a piece of cooked potato.
A slice of raw potato was placed in the top, the lid replaced and the container shaken in front of the chimps before a cooked piece was removed from the secret chamber and offered to them.
There were also other, clearly distinguishable containers that did not "transform" the food when shaken.
After the demonstration, the chimps could choose between the two types of containers, not knowing their contents -- and opted for the "cooking device" more often than not.
The next experiment was even more telling.
AFP
