Let's start cooking
Let’s start cooking

Breakfast: fibrous and bitter leaves; fruit. Lunch: bark; fruit; raw monkey meat and brains. Dinner: grubs; leaves; fruit.

No, not the latest food fad from Hollywood, but the diet of our closest living relatives, the chimpanzees. It is not exactly appetising or varied. We, on the other hand, have thousands of foodstuffs to choose from, and also an incredibly versatile range of techniques for altering their chemical composition through the application of heat. In other words, cooking.

Cooking is ubiquitous in humans. All cultures, from the Inuit of the frozen Arctic to the hunter-gatherers of sub-Saharan Africa, are sustained by food that has been chemically and physically transformed by heat. It was an incredible invention. Cooking makes food more digestible and kills off the bacteria that cause food poisoning. But where and when it started is hotly debated. You might call it a food fight.

No food without fire

Cooking cannot happen without fire, so the answer might be found by looking for evidence of the control of flames. This is an incendiary topic, as fire is a tricky thing to identify in the archaeological record. The evidence has literally gone up in smoke, and the remains of a deliberately lit fire are hard to distinguish from those of a natural one caused by lightning. This is why archaeologists look for signs of fire in caves.

Traces of ash found in the Wonderwerk cave in South Africa suggest that hominins were controlling fire at least 1 million years ago, the time of our direct ancestor Homo erectus. Burnt bone fragments also found at this site suggest that Homo erectus was cooking meat. However, the oldest remains of obvious hearths are just 400,000 years old.

“People on a raw vegetarian diet report persistent hunger despite eating frequently and usually have a lower BMI than vegetarians who eat cooked food”

The Neanderthals who evolved from Homo erectus some 250,000 years ago certainly created fires, as hearths have been found at many Neanderthal sites, some containing burnt bones. We also know from analysing their dental plaque that Neanderthals spiced up their diets with herbs. But we don’t know whether they habitually cooked their food.

The earliest firm evidence that our own species was cooking dates back just 20,000 years, when the first pots were made in China. The scorch marks and soot on their outer surfaces point to their use as cooking utensils. But all in all, archaeological evidence doesn’t paint a clear picture. We need to look elsewhere.

Around 1.9 million years ago some major changes occurred in hominin biology. Compared with its ancestors, Homo erectus had very small teeth, a small body and a much larger brain. According to a controversial hypothesis put forward by primatologist Richard Wrangham, these changes were driven by cooked food.