2. Cookery: The pivotal art
2mya to 200kya
Evolution is not a process with evenly spaced periods of time between species. Change can happen rapidly; almost impossibly so once 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 a 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 began as an accident and possible party trick became 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.
Cooked food is not more nutritious than uncooked food; it does, however, make nutrients significantly more accessible. 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. Homo erectus, which followed the habilines, had physically left the trees behind, with bodies truly adapted to land activities, particularly long-distance running. Homo is unique in its ability to travel long distances, needing only water to aid cooling. This function meant fast-moving prey would eventually tire from a relentless pursuit. Since fires were burning at night to protect groups of Homo, 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.
In this way cookery was essential to the evolution of humanity. It was also essential to the creation of society. With larger brains came greater social complexity. Of particular importance was the household division of labour. Notably, Homo sapiens are the only known species in which mothers and fathers share food with each other. The economics of cookery mandate that someone prepares and cooks food while others hunt and gather the ingredients. Men would hunt; women and older children would gather before returning to camp to cook the food. 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. Freed from cookery, the man could engage in politics, helping to lift the status of the family and potentially secure a greater chance of its survival. Of course, underpinning the household division of labour was the subjugation of women to essential but lower status functions and domestic violence.
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. But this does not mean equality (in this case, feminism) is anti-evolutionary, unnatural and fanciful. The mind and body of Homo has never been fixed. How this came about is, like so much else, unclear. Male and female humans are of a similar size, height and weight to each other, unlike many species of ape. Perhaps the early relegation of women arose from breastfeeding and the emotional bond between mother and child? Specialisation in activity maximised efficiency, as it does now. Swapping roles once a child was old enough to be cared for by an alloparent (non-parent substitute parents, like a grandmother or sibling) would have necessarily caused a drop in the amount of food being found and consumed. And, as we know all too well, once a social practice becomes entrenched it is hard to change it, especially if the society is superstitious and ritualistic.
The implications of the hypothesis that cooked food caused Australopithecus to evolve into Homo is that much of conventional food wisdom needs to be reconsidered. The Atwater system used to determine the nutrients in foods has brought about an entire industry of nutritionists that provides people, industry and government with overly simplistic information. For example, the reductionist calories in / calories out equation, along with nutrients in / nutrients out equation, form the basis of weight loss and nutritional science. 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. Anyone who cooks knows that browned and blackened food is unavoidable. One of the most popular false beliefs 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. Raw food in 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. Further examples of how scientists can be led astray by reductionism and the economics of research funding.
Reading list
Richard Wrangham, Catching Fire: How cooking made us human, Profile Books, 2009.
Ian Tattersall, Understanding Human Evolution, Cambridge University Press, 2022.
