Food Documentaries- Did the Discovery of Cooking Make Us Human?

Watch this video and learn why it is better to cook some type of food than to eat it raw. Learn why cooking our food created 'big human brains'?

 

Toss a steak on the grill and you may be reenacting an event that helped separate men from apes thousands of years ago. Cooking is something we all take for granted but a new theory suggests that if we had not learned to cook food, not only would we still look like chimps but, like them, we would also be compelled to spend most of the day chewing.

Did Cooking Make Us Human?

We are the only species on earth that cooks its food - and we are also the cleverest species on the planet. The question is: do we cook because we're clever and imaginative, or are we clever and imaginative because our ancestors discovered cooking? Horizon examines the evidence that our ancestors' changing diet and their mastery of fire prompted anatomical and neurological changes that resulted in taking us out of the trees and into the kitchen.

Cooking, according to a new theory from a Harvard anthropologist, was a key turning point in human evolution, and without it, we would still spend significant chunks of our day chewing heaps of raw foods, BBC News reported.

Humans would need to eat more than 10 pounds of fruits and vegetables a day -- a task which would require six hours of chewing, Harvard Professor Richard Wrangham told BBC News. Cooking, he said, allowed humans to begin eating meat.

Without cooking, an average person would have to eat around five kilos of raw food to get enough calories to survive.

"I think cooking is arguably the biggest increase in the quality of the diet in the whole of the history of life," he said.

"Our ancestors most probably dropped food in fire accidentally. They would have found it was delicious and that set us off on a whole new direction," he told BBC News.

When Homo erectus, the first truly "human" of our ancestors, evolved 1.8 million years ago, they had bigger brains and teeth than older species, along with the ability to walk upright and run.

Homo erectus also had smaller guts.

"Cooking made our guts smaller," Wrangham told BBC News. "Once we cooked our food, we didn't need big guts. They're costly in terms of energy. Individuals that were born with small guts were able to save energy, have more babies and survive better."

Cooking also allowed humans to spend more energy on thinking than on digestion, Professor Peter Wheeler from Liverpool John Moores University told BBC News.

It is already accepted that the introduction of meat into our ancestors' diet caused their brains to grow and their intelligence to increase.

Meat - a more concentrated form of energy - not only meant bigger brains for our ancestors, but also an end to the need to devote nearly all their time to foraging to maintain energy levels.

As a consequence, more time was available for social structure to develop.

Cooking Improved Human Diet

Harvard Professor Richard Wrangham believes there is more to it than simply discovering meat.

He thinks that it is not so much a change in the ingredients of our diet, but the way in which we prepare them that has caused the radical evolution of our species.

"I think cooking is arguably the biggest increase in the quality of the diet in the whole of the history of life," he says.

"Our ancestors most probably dropped food in fire accidently. They would have found it was delicious and that set us off on a whole new direction."

To understand how and when our bodies changed, we need to take a closer look at what our ancestors ate by studying the fossil records.

Our earliest ancestor was the ape-like Australopithecus.

Australopithecus had a large belly containing a big large-intestine, essential to digest the robust plant matter, and had large, flat teeth which it used for grinding and crushing tough vegetation.

None the less, it was Australopithecus that moved out of the trees and onto the African savannah, and started to eat the animals that grazed there.

And it was this change of habitat, lifestyle and diet that also prompted major changes in anatomy.

Bigger Brain

The eating of meat ties in with an evolutionary shift 2.3 million years ago resulting in a more human-looking ancestor with sharper teeth and a 30% bigger brain, called Homo habilis.

The most momentous shift however, happened 1.8 million years ago when Homo erectus - our first "truly human" ancestor arrived on the scene.

Homo erectus had an even bigger brain, smaller jaws and teeth.

Erectus also had a similar body shape to us. Shorter arms and longer legs appeared, and gone was the large vegetable-processing gut, meaning that Erectus could not only walk upright, but could also run.

He was cleverer and faster, and - according to Professor Wrangham - he had learned how to cook.

"Cooking made our guts smaller," he says. "Once we cooked our food, we didn't need big guts.

Professor Peter Wheeler from Liverpool John Moores University and his colleague, Leslie Aiello, think it was this change in our digestive system that specifically allowed our brains to get larger.

Cooking Helps in Energy Transfer

Cooking food breaks down its cells, meaning that our stomachs need to do less work to liberate the nutrients our bodies need.

This, says Wheeler, "freed up energy which could then be used to power a larger brain. The increase in brain-size mirrors the reduction in the size of the gut."

Significantly Wheeler and Aiello found that the reduction in the size of our digestive system was exactly the same amount that our brains grew by - 20%.

Professor Stephen Secor at the University of Alabama found that not only does cooked food release more energy, but the body uses less energy in digesting it.

He uses pythons as a model for digestion as they stay still for up to six days while digesting a meal. This makes them the perfect model as the only energy they expend is on digestion.

His research shows that pythons use 24% less energy digesting cooked meat, compared with raw.

So being human might all be down to energy.

Cooking is essentially a form of pre-digestion, which has transferred energy use from our guts to our brains.

According to Professors Wheeler and Wrangham and their colleagues, it is no coincidence that humans - the cleverest species on earth - are also the only species that cooks.

Want to learn more about food and cooking? Read The Science and the Lore of the Kitchen

Documentary Film Summary: Did the Discovery of Cooking Make Us Human?

In Horizon:Did Cooking Make Us Human?, a clutch of determined scientists set out to discover the extent to which diet played a role in the evolution of the human brain, using a variety of mildly alarming gadgets. Professor Peter Ungar has a contraption he calls the Bitemaster 2, a mechanical chewing machine he has fitted out with genuine Australopithecine gnashers. For the first time in three million years they were set to work on a carrot, with remarkable success, considering. On raw meat they performed less ably, but teeth from a later human ancestor – smaller, sharper, "crestier" – made short work of it. You certainly wouldn't want to get your finger caught in there, as Prof Ungar nearly does. "Wait!" he yells at his start-button-happy colleague.

The Australopithecines didn't eat animals; skulls with fang holes show that it was the other way round. At some point in our evolutionary history it's clear that we developed a taste for animal flesh, but it's not altogether obvious when, or why. Hunting is tricky, risky, time-consuming and exhausting, and there is little evidence that Homo habilis, for example, was any good at it. In search of answers, Professor Travis Pickering went to meet some Namibian Bushmen to get a feel for the hunter-gatherer lifestyle. Although it's not glamorous work – it takes the Bushmen four hours in 40-degree heat to dig a porcupine out of its hole – they left one in no doubt as to its importance. "I don't particularly like eating porcupine," said one of the Bushmen, smiling shyly, "but meat is meat."

The programme's most interesting contention was that cooking led directly to our bigger human brains. "Cooking is huge," said Professor Richard Rangham. "I think it's the biggest increase in the quality of diet in the whole of the history of life." Again, no one is sure when our ancestors first became chefs – estimates range from two million to 800,000 years ago – and the fossil record hasn't been much help so far. They've found charred animal bones (evidence of hunting prey with fire) and butchered animal bones (evidence of meat-eating) but no charred and butchered bones – yet.

As a popular-science programme this erred slightly on the side of repetition, and made one a little impatient. As a cookery programme, it put you off your dinner. It's not very appetising to watch a scientist chew up a raw potato and spit it into a digesting machine, or to see a professor push a length of raw steak into a live snake. The advantages of a cooked diet are, from an evolutionary point of view, legion: you absorb more calories while expending less energy, and you can make do with a smaller, less elaborate gut. Which is just as well, because I didn't feel like eating much of anything afterward.