Humans are the only species on earth that cook food before eating. British primatologist Richard Wrangham argues that cooking food was a very important element in the process of evolving into humans. He argues his hypothesis in his book ‘Catching Fire: How Cooking Made Us Human’ published in 2009.
According Wrangham Homo Erectus evolved about 2000 years ago because of this unique trait. Its evolutionary effect was profound because it increased food efficiency. This meant less time was spent on foraging, chewing and digesting food. Humans therefore developed a smaller digestive tract that worked much faster. In turn that freed up more energy and enabled larger brain growth.
Cooking required control of fire. This enabled out ancestors to stay warm and to defend themselves against dangerous predators. This helped them to establish a ground based lifestyle. He points out that humans have now become so evolved for eating cooked food that we would no longer be able to maintain reproductive fitness if we only eat raw food.
Critics of Wrangham’s theory question whether there is enough archaeological proof to support his view that cooking fires were used long ago enough to have pushed the evolution of the digestive tract to the extend that he describes it.