Does out linguistic ability or our intelligence make us humans? There must be something that separated us from the apes in the first place. Cooking could be one of the causes that helped us transform form ape to humans. Let us see if this logic has some meat or not.
Humans are the only one who cooks food. Language and intelligence are present in other species also but it is only we who get the joy of eating the burger and pizza. It is believed that Homo sapiens invented cooking and before that our natural diet included only raw foods like raw meat, fruits and vegetables. But can be now survive on raw food. There are reports from the medieval period that Mongols did not eat cooked food for weeks while moving and not lighting a fire. They would draw blood from the horses to drink and put chunks of raw meat under the saddle to soften them and eat. By seeing their conquest it surely did not have any negative effect on them.
Though we can survive on raw food but it can also be said that we evolved to cook food. In 2006 an experiment was conducted by the BBC. 9 obese and unhealthy people were kept in an enclosure in a zoo and fed only raw fruit, nut, vegetables and a small portion of cooked fish. They had the recommended calorie intake of 2000-2300 calories per day. After the experiment it was found that their blood pressure fell to normal levels and they lost an average of 4.4 kgs weight. But if our ancestors ate such high quality diet with all the calories required and also lost weight then it would have been devastating for us. Apes grew in size and became fat eating such diet but humans haven’t.
Raw food diet leads to weight loss in humans. It can show signs of chronic energy deficiency. 50 percent of women on such diet would stop menstruating. Though this would be great to protect them from wild animals that could smell blood from far away but it would have serious fertility consequences and therefore evolution. So a raw food diet would have seriously threatened the population who were basically hunter gathers and required high energy to survive.
Cooked food provides more energy than raw food- that’s why we lose weight. Our primary aim to eat is to gain energy. Cooked food provides more energy because before cooking we crush them or reduce the size of it or soften them or grind them, thus making it easier for the body to absorb the energy. Raw food is tougher to digest and therefore require more energy to break them.
What was the advantage of the invention of cooking by our ancestors? First we have to understand evolutionary trade off. In evolution for one trait to become predominant it has to give up or reduce the dominance of another trait. Ostriches gave up flying to gain more speed on ground. Turtles chose heavy shells by trading off mobility. Giraffes chose to eat from trees and so have long necks. For the humans we traded off by having smaller mouth, intestine, weaker jaws and digestive ability unlike the apes and in return we developed bigger brains.
As our ancestors started using fire to cook food, natural selection helped us to get more energy from less food. Our stomach is about 40 percent smaller than our ape ancestors. This surplus energy was transferred for the development of bigger brain. Raw food needs a lot of chewing; chimps spend about 6 hours a day chewing. If we had the diet of a chimp then we would use 40 percent of the day just to chew raw food. That would be a full time job for us. Currently we spend only about 5 percent of the time chewing cooked food.
So the biological benefits of cooking food had a major impact in the development of our body and mind which led to the development of the intelligent species as we are today.
Thank you Telesfor sir