2. Cookery: Brainwork
2mya to 200kya
There is something genuinely atavistic about sitting by a fire: the smoke, the vivid flame, the heat and the magic, the transformation of one object into another, the wood to ash, the raw to cooked and the smell of burnt meat, a votive to the gods and a pleasure to mortal noses.
Evolution is not a process with evenly spaced periods of time between species. Change can happen rapidly; almost impossibly so if advantageous genes exist within a population. By eating raw meat Australopithecus acquired the nutrients necessary for larger brains. And since eating meat required scavenging and hunting, the ability to think more complicated thoughts, communicate their meaning and persuade others to cooperate meant there was an advantage to having larger brains. By 2.3mya, larger game animals were being hunted and consumed. While killing an animal is an act of violence, Australopiths became less quarrelsome with each other and, therefore, more cooperative. This process of self-domestication arose as those individuals with lower normal blood levels of cortisol were better suited to social relations. Dogs eventually followed suit.
Evolution sped up when late members of the genus – often called Homo habilis instead of Australopithecus habilis – or some other predecessor species began to control fire. The habilines existed for a shorter period of time, in evolutionary terms, from 2.4mya to 1.6mya. The best theory for the evolutionary acceleration is that this species domesticated fire and began cooking food. (Evidence of deliberate fires is, understandably, hard to come by.) The fire probably came accidentally from toolmaking, especially in the early days before the differences in stone types was truly appreciated. Although the sparks caused by banging most stones together are cool, the sparks from banging pyrite ore (fool’s gold) and flint together are dependably hotter. What probably began as an accident became a party trick before it was turned into a weapon against predators and each other. This winning combination of accident and experimentation – so familiar to historians of science and technology – gave rise to campfires and cookery.
There was a complicated confluence of changes which reinforced evolutionary progression. Campfires burning at night would protect groups of Homo, enabling better sleep with fewer watchers. Eventually, the presence of the fire gave rise to the cooking of raw food, resulting in greater nutrient acquisition. Homo erectus, which followed the habilines, had physically left the trees behind, with bodies truly adapted to land activities, particularly long-distance travel. (Homo is unique in its ability to journey long distances, needing only water to aid cooling.) This function meant fast-moving prey could be hunted, as other animals will eventually tire from a relentless human pursuit. The evolutionary shedding of fur associated with the suitability for long distance travel was encouraged because it was possible to stay warm at night during cool weather and without clothing.
Cooked food is not more nutritious than uncooked food; it does, however, make nutrients significantly more accessible to the body. Whereas apes still eat raw food all day long, hominins were able to spend much less time eating while acquiring the nutrients necessary to sustain function of their energy-demanding brains. Crucial to this adaptation was the need for a more energy efficient gastrointestinal system. With a more efficient way of acquiring nutrients, there arose more time during the day to hunt and gather and at night to socialise.
Cookery was essential to the creation of society. Eating cooked food further increased the nutritional advantages of eating raw meat. Larger brains brought the ability to develop greater social complexity. Of particular importance was the household division of labour. Curiously, Homo sapiens are the only known species in which mothers and fathers share food with each other in addition to their young. The economics of cookery mandate that someone prepares and cooks food while others hunt and gather the ingredients. Specialisation meant a higher chance of survival. Understandably, women were constrained by childbirth and breastfeeding which would have ensured periods of absence from the hunt and, therefore, drops in efficiency. However, gathering was better suited to groups of women of varying ages and older children. (As we will see in a future post, younger children were left with alloparents at camp.) Cooking was done at the camp by women and older children. Men were free to hunt or engaged in camp politics, potentially lifting the status of the family and aiding its survival. Hunting was much less reliable than gathering. Often the gatherers would have staple foods which they could return to for a reliable source, such as roots. The hunter would return to camp, with or without meat.
Of course, underpinning the household division of labour was the subjugation of females to essential but lower status functions. And with this subjugation came domestic violence and complex custom to resolve disputes. The uncomfortable conclusion drawn from the cooking hypothesis is that the household division of labour was essential to human evolution. Such a view is not inconsistent with human history generally with respect to labour. This hypothesis does not mean equality (in this case, feminism) is anti-evolutionary, unnatural and fanciful. The mind and body of Homo has never been fixed. But once a social practice becomes entrenched it is hard to change it, especially if the society is superstitious, hierarchical and ritualistic.
The implication of the hypothesis that cooked food caused Australopithecus to evolve into Homo is that much of conventional food wisdom needs to be reconsidered. Among the vast catalogue of profit-seeking pseudoscience is that of probiotics. Interestingly, microbiology is linked to the cooking hypothesis. Richard Wrangham, the anthropologist who devised the hypothesis, and his doctoral student Rachel Carmody, helped to advance the science in full appreciation of its complexity. While the science remains uncertain, peddlers of quack remedies abound. Also in the catalogue is much of nutritional and weightloss industries that provide consumers with overly simplistic information, including the reductionist calories in / calories out equation, the nutrients in / nutrients out calculation and the Body Mass Index. Similarly, the belief in the carcinogenicity of Maillard compounds, which has led people to avoid eating burnt meat or any food that has browned during cooking, is at odds with humans being the only species that has evolved to eat cooked food. As any cook knows, browned and blackened food is unavoidable in cooking, especially when food is exposed to thermal radiation. One of the most popular fallacies is that humans thrive on raw food. Humans cannot survive long term on raw diets and would face inevitable starvation without calorie-dense industrial fats. A salad may be pleasurable, but it’s inefficient for getting energy and has higher levels of pathogens that haven’t been killed or reduced by the cooking process.
Reading list
Richard Wrangham, Catching Fire: How cooking made us human, Profile Books, 2009.
Ian Tattersall, Understanding Human Evolution, Cambridge University Press, 2022.
Watch list
