The big human brain is expensive. Every day, brain activity consumes a quarter of the calories of energy needed to power the human body. To survive, humans must find and consume enough food to supply all those calories.
Anthropologists think our ancestors solved this problem by learning to cook their food with fire. Cooking begins the breakdown of fiber, proteins, and toxins, making it easier for our digestive tract to extract the nutrients food contains, as well as killing dangerous germs. Because cooking allowed our ancestors to extract more usable calories from their food, it could have fueled the explosive increase in brain size that led to Homo sapiens. Unfortunately, evidence that early humans cooked isn’t easy to come by.
In 2022 an international team of anthropologists announced their discovery of direct evidence of human cooking seven hundred and eighty thousand years ago—far earlier than previously known. The researchers studied a prehistoric garbage heap found at an early human campsite in what is now Israel. In the garbage heap, they found accumulations of the teeth of a type of large carp-like fish.
They surmised humans had eaten the fish and discarded the hard teeth. By studying crystals formed in the enamel of the discarded teeth, the researchers showed that they had been exposed to high temperatures between four hundred and nine hundred degrees Fahrenheit—exactly the temperatures expected if the fish had been cooked with fire.
Today, we know that cooked fish is rich in omega 3 fatty acids, zinc, iodine, and more—all highly beneficial to brain health. The finding is new evidence that cooking may have played a big role in human brain evolution.