The act of cooking is fundamental to our existence, and some researchers believe it was the key that unlocked the extra calories necessary for our ancestors to develop larger brains. But when did this culinary revolution begin? While the exact timing remains uncertain, evidence suggests that humans were cooking food at least 50,000 years ago, and potentially as early as 2 million years ago. This evidence comes from two primary sources: archaeology and biology.
Archaeological evidence for cooking comes from the discovery of cooked starch grains found in dental calculus, or hardened dental plaque. “People can find it in teeth that are 50,000 years old,” explains Richard Wrangham, a retired professor of biological anthropology at Harvard University and author of “Catching Fire: How Cooking Made Us Human.” However, evidence for cooking prior to this period is more elusive. Scientists often look for evidence of controlled fire use, but this doesn’t necessarily equate to cooking. Early humans could have used fire for warmth or toolmaking. “There’s evidence of fire all the way through the archaeological record,” says Bethan Linscott, an archaeological geochemist at the University of Oxford. “But the problem is distinguishing whether it was controlled fire or fire that was scavenged – you have a wildfire moving through the landscape and you have hominins who are able to pick up a smoldering twig and take advantage of that in order to maybe process tools or cook.”
Researchers seek out what’s known as a combustion structure – evidence of a controlled fire, often indicated by stones arranged in a circle with ash, phytoliths, burnt artifacts, and other signs. These structures have been discovered in locations predating Homo sapiens, suggesting that earlier hominins also utilized fire. In Qesem Cave, Israel, scientists unearthed a 300,000-year-old hearth near butchered animal remains, while a cave in Suffolk, England, contains a 400,000-year-old hearth with burnt bone and flint from toolmaking. Even further back, ash found in Wonderwerk Cave, South Africa, suggests that cooking may have occurred as early as 1 million years ago. “[The cave] is so deep, about 30 meters [100 feet] deep, that it couldn’t possibly have been a natural process producing this ash a million years ago,” notes Wrangham.
Evidence of controlled fire in Kenya dating back 1.6 million years also hints at early cooking practices. However, more convincing evidence comes from a site in Israel called Gesher Benot Ya’aqov, where researchers discovered a 780,000-year-old hearth containing not only circles of stones but also fish bones that showed signs of being heated.
Biological evidence for the origins of cooking is found in the unique evolutionary adaptations of the human body. “We are as a species different from every other species on Earth because we are biologically adapted to eating cooked food,” Wrangham asserts. Studies of individuals following raw-food diets reveal that participants often lose weight, and a significant portion of women stop menstruating. This highlights the importance of cooked food in our biological processes. The question then becomes, when did this adaptation occur? Wrangham suggests it may have begun even before the emergence of modern humans. Homo erectus, the first hominin to exhibit less primate-like and more human-like body proportions, may have been the first to cook food.
One of the major distinctions between humans and our primate relatives is the size of our guts. Cooking allows us to pre-digest our food, resulting in smaller guts compared to primates. “Our large intestine, our colon, the last bit of the gut, is about two-thirds of the size that it would be if we were a chimpanzee, a bonobo or a gorilla,” explains Wrangham. This allows us to have relatively flat stomachs, unlike the bulging stomachs of primates after a meal. To accommodate their larger guts, nonhuman primates have wider pelvises and flared ribs. Our human ancestors lost these features around 2 million years ago, a time that also saw a significant decrease in the size of chewing teeth – further evidence of a dietary shift towards softer, easier-to-chew food.
This aligns with the emergence of Homo erectus approximately 1.8 million years ago. “The big story here… is that cooking began about 1.9 million years ago with the origin of the species that most looks like us in human evolution, Homo erectus,” Wrangham concludes. He argues that cooking and fire control were likely responsible for the evolution of Homo erectus. However, without definitive evidence of controlled fire use from that distant period, the idea that Homo erectus was the first cook remains a topic of debate. “There’s a lot of people still working on it, and I imagine there will be for a long time, and I don’t know if they’ll ever be able to pinpoint exactly when,” admits Linscott. The search for the origins of cooking continues, promising to unravel more secrets about our fascinating evolutionary journey.
