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SYNAPSE Workshop 2015 | June 30 – July 4, 2015


13.06.15 | PROJECT: Blog | AUTHOR: Anna-Sophie Springer



And to every beast of the earth and to every bird of the heavens and to everything that creeps on the earth, everything that has the breath of life, I have given every green plant for food.

—Genesis 1:30

The mere invention of fire, the cornerstone of the whole cultural edifice, as the fable of Prometheus so well expresses it, presents insurmountable difficulties in our conjectures about man in a crude state of civilization.

—Friedrich Schlegel


In my prior post on human–ape relations, I took cues from the roles monkeys have played in art, mythology, and evolutionary theory, with themes of communication and empathy crystallizing toward the end of the piece. Although verbal language has been considered one of the crucial factors distinguishing the human from other animals, countless studies and examples underscore that nonhuman species such as apes are indeed quite capable of complex communication, too, even if spoken words are not among these being’s skill sets.

Another trait differentiating humanity is our mythological ability of making and controlling fire. Similarly to the human’s evolutionary monopoly on verbal language, so far, there is also no other species known that actively masters fire. But a recent chimpanzee study now claims that apes do indeed favor one of fire’s cultural products—cooked food. In the context of the HKW and SYNAPSE’s current focus on human–ape scenarios, the evolutionary conclusions scientists propose from these gastronomic observations are interesting fodder.

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As the only fire-makers in the world, humans have also logically been considered the only species on this planet habitually preparing and eating cooked food. Apparently not a single tribe or society is known that didn’t or doesn’t cook, and there are many foods a chimpanzee can eat that we would find hard to digest or outright harmful, unless we’d transform their chemical properties first through the application of thermodynamics. Already Charles Darwin praised the evolutionary significance of relating fire and cooking in The Descent of Man:

[The human] has discovered the art of making fire, by which hard and stringy roots can be rendered digestible, and poisonous roots or herbs innocuous. This discovery of fire, probably the greatest ever made by man, excepting language, dates from before the dawn of history. These several inventions [weapons, tools, traps, etc.], by which man in the rudest state has become so pre-eminent, are the direct results of the development of his powers of observation, memory, curiosity, imagination, and reason.

More currently, also Harvard anthropologist Richard Wrangham studies the role of fire in human evolution. Going beyond its socio-environmental conditions of building and dwelling (warmth and light), he associates fire quite directly with the cognitive skill of thinking. Expanding on Darwin’s argument, Wrangham contends that it was precisely a benefit of cooked food, which led to the bigger brain and body sizes of hominid species. Because consuming cooked nourishment is easier to digest, releasing calories and nutrients faster and at less metabolic “cost” than raw foods, scientists like Wrangham see a rather direct metabolic relationship between fire and human cerebral evolution—ultimately enabling what philosopher Friedrich Schlegel has called “the whole cultural edifice.”

According to an article on the history of cooking in Smithsonian Magazine, a number of differences in human versus ape body shape can be traced back to individual species’ eating habits and are most visibly reflected in the torso:

The calories to fuel the bigger brains of successive species of hominids came at the expense of the energy-intensive tissue in the gut, which was shrinking at the same time—you can actually see how the barrel-shaped trunk of the apes morphed into the comparatively narrow-waisted Homo sapiens. Cooking freed up time, as well; the great apes spend four to seven hours a day just chewing, not an activity that prioritizes the intellect.

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Above: Proboscis monkeys at the feeding station in Labuk Bay Proboscis Monkey Sanctuary, Borneo, photo courtesy

Ever wondered why essay writing makes one so hungry? In contrast to apes “just chewing” away, “[a] human body at rest devotes roughly one-fifth of its energy to the brain, regardless of whether it is thinking anything useful, or even thinking at all. Thus, the unprecedented increase in brain size that hominids embarked on around 1.8 million years ago had to be paid for with added calories either taken in or diverted from some other function in the body.”

Adapting to cooked food afforded our fossil ancestors with that additional energy needed.

But since when exactly did they begin to play with fire?

The art of using fire by our forebears has been described as more groundbreaking for human evolution than the introduction of agriculture in the Holocene around 11,000 years ago. However, it turns out that the earliest use of fire continues to be subject of debate, not least because “no actual hearths are found until the appearance of Neanderthals at the end of the Middle Pleistocene.” But some palaeontologists have claimed extremely ancient archaeological clay finds from the Stone Age period as evidence for fiery beginnings reaching as far back as the “Lower Pleistocene”—or those critical 1.8 million years ago referred to above.

Moving forward into the Anthropocene, it is hardly surprising however to learn about a recent study with chimpanzees that complicates a notion of human exceptionalism based on the gastronomic. Interested in understanding whether our closest relatives possess the cognitive-psychological skills required to cook, primatologists Felix Warneken and Alexandra G. Rosati, conducted a series of experiments in a chimp sanctuary in Congo. Based on the general question, if the animals would manifestly recognize a difference between raw and cooked food, Warneken and Rosati furthermore asked if a positive result of this first problem would inspire any additional significant behavior.


Above: Ferdinand van Kessel, Festmahl der Affen [The Monkeys’ Feast], 17th. c. Wikimedia Commons

According to their article published earlier this month in the Proceedings of the Royal Society B, the two authors report that their test subjects did indeed seem to prefer cooked over raw vegetables when presented with a choice. To determine furthermore whether chimps could comprehend the relationship between a vegetable in its raw and cooked state, they devised a test based on two bowls. If food was placed inside the bowls, after a short delay, one container would dispense it raw (the way the ape originally placed it inside), while the other bowls would dispense a chunk of the same food but cooked. The scientists explain that when given the choice, the apes almost always went for the “cooker” even though that meant both letting go of the obtained slice and accepting a waiting period until receiving it back. Rather than devouring their food instantly—so far considered the normal behaviour of chimpanzees—the test portrayed the apes as more mindful eaters than numbly chewing automatons.

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Above: One of the short test videos showing a chimpanzee handing over its food to have it “cooked.”

While Warneken and Rosati’s study doesn’t question our unique relationship to fire, their conclusions seem to support such evolutionary hypotheses, which positively assume the cognitive abilities of very early hominid species for making culinary use of fire. “The logic is that if we see something in chimpanzees’ behavior, our common ancestor may have possessed these traits as well. If our closest evolutionary relative possesses these skills, it suggests that once early humans were able to use and control fire they could also use it for cooking,” said Warneken in the Guardian. Affirming Wrangham’s thesis, cooking—and thus the use of fire—has potentially indeed existed for many hundreds of thousand of years longer than commonly believed.

From a more simple perspective, the observation that chimpanzees have a clear sense of liking one dish over another—and that that preferred dish first ought to be prepared a bit—is definitely one more compelling example for our primate cousins’ cognitive similarities to ourselves.

But where there is good food, good drink mustn’t be lacking. Like us, monkeys (and other animals) also have been observed to indulge in some booze, at least occasionally. Extrapolated from such behavior, a theory termed the Drunken Monkey Hypothesis suggests an adaptive benefit of alcohol consumption in evolutionary deep time, potentially stimulating a hominid being’s appetite and thus increasing their calorie intake. Just this last week a long-term study of seventeen years was published about a group of forest chimpanzees in Guinea, which is regularly getting drunk together on fermented palm tree sap. To access the drink, the apes have been observed to form little spoons out of leaves.

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On that note, happy Saturday night and Cheers!

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