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…..
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. As a consequence, more time was available for social structure to develop.
– from BBC, Learning to Cook Produced Bigger Brains
Changing food habits is a good example of how we shape our own evolution.
Our evolved biology makes our behavior and culture possible. Our behavior and culture changes, and this allows us to make use of our evolved potential in new ways. Both of these changes our selection pressures. Which in turn changes us biologically as a species. And this changes what is possible for us as individuals and as a culture.
We have evolved so it is possible for us to use tools and cook food. Cooking food allows us to make better use of food nutrients, which in turn allows us to make different and new use of our evolved potential. Both of these changes our circumstances and selection pressures, so different characteristics are selected for. This changes us biologically as a species. And this opens new options for us as a species and a culture.
Nowadays, our own culture is perhaps the most significant source of our own evolutionary change, as it has been for tens or hundreds of thousands of years. Through culture, we change our social and ecological environments, which in turn changes the selection pressures, which in turn changes who we are.
It is not good or bad. It doesn’t necessarily mean we evolve to be more or less mature in terms of ethics or intelligence. And in what ways we change ourselves is mostly speculation, although often useful speculation.
As mentioned in an earlier post, one way we may change ourselves is through selection for those who are more mature. In theory, the ones who have a richer set of stories to draw from, and hold these more lightly, will experience less stress and make better choices, so their offspring may have a better chance to survive and reproduce. On the other side, there may not be much correlation between number of children and maturity in modern society.
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.
Without cooking, an average person would have to eat around five kilos of raw food to get enough calories to survive.
The daily mountain of fruit and vegetables would mean a six-hour chewing marathon.
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.
– from BBC, Learning to Cook Produced Bigger Brains
Is there something fishy about traditional anthropological and evolutionary theories around food? At first glance, it may seem so.
Sure, expanding our diet to become omnivores had an impact. It gave us more proteins in our diet, and a wider menu of choices from our environment. But does it mean the difference between foraging the whole day for food, and having time to spare? Perhaps not, as I seem to eat about the same amounts whether I eat a vegetarian diet or an omnivore diet. This does require foods that have proteins, such as legumes, but those were probably available in our ancestor’s environments as well. Placing too much emphasis on meat-eating as an evolutionary force may be the product of a culture where meat is expected as a centerpiece of every major meal.
The transition to cooking makes more sense to me. Cooking makes more nutrients available, and it also expands our food choices. With cooking, we can eat roots and other plant parts that otherwise would be undigestible to us, meat is much easier to chew and eat, and it also sterilizes some foods that otherwise would make us sick. But here too, we seem to find people who counter this theory. What about people who eat only raw foods? They seem to be doing well, and they are not eating more than the rest of us. Of course, some don’t seem to do so well on a raw diet. And it makes a difference that we have any type of ingredients available to us in the grocery stores.
There is surely some impact from shifting into both an omnivore and a cooking diet. But is the transition as significant as they say? I don’t know.
In any case, our changing food habits is a good example of how we shape our own evolution. We change our habits and behavior, in large part through our culture, which in turn changes our evolutionary selection-pressures, which in turn changes us biologically as a species, which in turn changes what is possible for us as individuals and as a culture.
Nowadays, our own culture is perhaps the most significant source of evolutionary change for us, as it has been for tens or hundreds of thousands of years. Through culture, we change our social and ecological environments, which in turn changes the selection pressures, which in turn changes who we are.