May 07 2012
As the hominin body routed more energy to the brain, our biological apparatus got diminished in effectiveness
Every animal in the animal kingdom would have liked to have bigger brains. But most animals don’t have brains like we have. It is because most animals don’t know how to manage big brains. They don’t know how to meet the energy demands of the big brains. As our brain uses energy it generates heat, and in the process it gets overheated. Fortunately, our hominin ancestors resolved the problem of overheat by developing a system of sweating that is managed by the brain.
Cooking is one of the most important innovations for softening food. This is perhaps the reason why we are called coctivores (those who love to eat cooked food). Food scientist Heribert Watzke says, “Our dental anatomy is actually made, not for tearing down raw meat from bones or chewing fibrous leaves for hours. It is made for a diet which is soft, mushy, which is reduced in fibres, which is very easily chewable and digestible”. If there was no cooking, our ancestors would literally be chewing the gathered food for the rest of the day to get enough calories to survive. Wrangham believes that great apes have helped us a great deal to understand our own behaviour. Life is easier if we understand biological rules. “Recognition of the deep contradictions in humanity binds us to our past, and also lights our future,” believes Wrangham. It is estimated that sometime around 250,000 or 300,000 years ago cooking really got going. There is archeological evidence that shows the presence of earth ovens during that time. Wrangham, however, thinks long before earth ovens came along we must have learned to cook.
Once cooking happened, it showed us completely new ways of utilising our resources. We began to look at the environment with new eyes. We began to see human male-female relationship from a new perspective. Wrangham’s idea is that once females were ready to make a meal by collecting food and cooking it, they became vulnerable to big males (he calls them “scroungers”) who took away their food. Rather than collecting and cooking the food, the easier option for the males was to take it when it is ready. This necessitated the need of females protecting themselves from ‘thieving males’. Perhaps, as Wrangham suggests, this is the origin of human male-female relationships.
(The writer is a biotechnologist and ED, Birla Institute of Scientific Research, Jaipur)