As much time as we seem to devote to eating – this town has turned the two hour lunch into an art – most of us spend only about 5% of our day noshing. Our earliest ancestors, though, spent upwards of 48% of their day chewing the fat. Literally. Why and how we came to spend less time eating and more time doing other, more productive things like Facebooking and tweeting, though, was not always clear. Scientists studying the role of cooking in our evolution may have an answer: in a paper published a few weeks ago in Proceedings of the National Academy of Sciences, the researchers conclude that this enormous difference may be attributed to our ancestors' discovery of cooking almost 2 million years ago.
Comparing 14 different specimens of the Homo genus, scientists tracked a steady decline in the size of our molars that correlated consistently with an overall decline in our body mass. About 1.9 million years ago, though, our molars suddenly were smaller than they would have expected. This change “occurred too rapidly to have been driven by the rate of head, jaw, and body-size evolution alone.” The researchers attribute this drastic change to the advent of cooking, implying that fire was discovered much earlier than previously believed.
The theatrics of the restaurant industry aside, we cook essentially to break down foods and make them easier to swallow and digest. With softer foods, our ancestors no longer needed their large, strong molars to gnaw on raw food.
More than a simple change to our physical appearance, though, cooking accelerated our evolution. “The ancestors of modern humans who invented food processing, including cooking, gained critical advantages in survival and fitness through increased caloric intake,” the researchers explain. Thanks to these first chefs, we became “biologically adapted for cooking food.”
After that giant leap for mankind, you know the rest of the story: we invented sliced bread, the microwave, and fast food. In a few decades or centuries, our robots will do the cooking for us so we will have even more time to squander and evolve. There is grandeur in this view of life.