Dietary Darwinism

Today, as humans can put nearly anything on their plates with minimal effort, food has taken on a life of its own.

a conversation with Jonathan Silvertown

by Henry Albert

We’re always hungry. Hunger has fueled our existence, toughened by an exhausting game of trying to eat as much as possible while avoiding being eaten. Winning this game has allowed us to reach the top of the food chain, elevating ourselves well above our initial starting point—as prey, mostly. We were food, we still are food, we still seek and provide it. We are what we eat: Did our dietary choices influence our evolution? And what significance does this ancient impact hold as we push forwards, devouring our naturally unnatural world? 

Even before we started walking on two feet, 5 to 7 million years ago, we were molded by a natural selection brought on by our ecosystem. Over time, we also started acting on our environment, which means our evolution stopped being based on external factors alone, and directly swayed by our own doing: this process is called a niche construction, and building tools, hunting in groups or controlling fire to cook food are all excellent niche constructions. Treating food and eating meat may have actually provided the spark for our definitive distancing from other great apes, creating the energy needed to develop our uniquely large and complex brain.

Jonathan Silvertown is a professor of evolutionary ecology at the Institute of Evolutionary Biology at the University of Edinburgh. He’s authored several books on ecology and evolution, and one dedicated exclusively to natural selection and menu selection. He says:

“People have always been fascinated by the ways in which humans are different. Most of them look for elements of uniqueness, like language, or speak in matters of degree, like intelligence. But in most respects we’re a development of things you find in other animals. Other species of homo cooked as well; our uniqueness in this aspect is partly due to the fact that all other human species have gone extinct, possibly with our help.”

Silvertown’s Dinner with Darwin follows the tortuous path of evolving food: “Evolution is the process that not only produced our food, but also produced us. Our relationships with food demonstrate evolution in ourselves and in what we eat.”

Nutrition has shaped our genetic framework. Our small intestine represents almost 60% of our gut’s volume, more than double that of other great apes, who in turn have a large intestine that is about 45% of their guts, two times more than in humans. These physical differences reflect differences in alimentation: Humans have always preferred easy to digest foods like grains and other animals—cooked–rather than relying almost exclusively on basically raw plants.

But nutrition has also pushed us to change the genetic framework of the things we eat: The artificial selection of plants and animals for domestication, brought on by evolving humans, mirrors and replicates the effects of natural selection. Or, as Silvertown exemplifies in Dinner with Darwin: “Consider what plant breeders have managed to create from wild cabbage, a weedy and inedible-looking plant found around the coasts of northern Europe. From this unpromising beginning, centuries of selective breeding by unknown horticulturalists who knew nothing about genetics our evolution generated cauliflower, broccoli, Brussels sprouts, kohlrabi, and kale, not to mention cabbage bred in the Channel Islands, near the coast of Brittany, France, which produces a stem that is tall and strong enough to make a good walking stick, which used to be grown for just that purpose.”

This process of selection, which began and developed with the institution of agriculture, also precedes the scientific method, Silvertown explains: “Trial and error in cooking is its connection to science. The process of testing something is present in the way we find new food. For instance, cassava is a root that is full of cyanide. It’s a very rich source of starch, but it’s deadly poisonous. Human selection has created two varieties, one of which doesn’t contain cyanide. But people still grew both, the one without poison closer to the house, and the poisonous one further away. This is a choice, a way of protecting your cassava by keeping it inedible. How did people discover its complicated processing method? People found this root and tasted it. Taste guided us from the beginning.”

We’re not defined only by the aim to gather and eat food. What also sets us apart is our innate desire to share it. Evolutionary biologists have theorized various models to frame the evolution of food-sharing behaviors in humans: Kin selection, reciprocal altruism, tolerated theft, group cooperation, and costly signaling. The basic assumption of most of these models is that accumulating more resources increases reproductive fitness. 

Silvertown continues: “One reason this propensity to share food may have evolved is because we hunted large animals by cooperating. Homo erectus, for example, seems to have hunted elephants. This resulted in more than enough food for everybody, favouring cooperation.” 

He goes on to write: “Evolution is all about the potential of its ingredients, and so is good cooking. We have survived the waxing and waning of ice sheets and deserts, and then thrived, multiplied, and occupied every continent because we are adaptable, intelligent omnivores. If we were not, we would be as endangered as the giant panda that eats little other than bamboo shoots. Our evolutionary history has indeed shaped our dietary capabilities, but it has broadened rather than narrowed them.” 

Our relationship with nourishment has developed with us, in an endless chain of duplicating influences. The world is overflowing with adaptable, intelligent omnivores, and feeding a planet of 8 billion of them means nourishment is still a crucial necessity and at the same time a complex global phenomenon. As man became increasingly conditioned by man-made structures such as economy, politics, and society, so did food.

He comments: “Food will always stay an obsession—it is too deeply rooted in our biology, in our idea of pleasure and security, in our social lives. And it has evolved to become a cultural phenomenon. We’re just more aware of it now, because we’re globally connected. Edinburgh, which is in all aspects a small city, has more than 1,000 restaurants. 40 years ago there was very little choice. People seek variety — the avocado, which was completely unheard of decades ago, is now a common part of diets globally.” Mexico alone supplies half of the world market, and cartels fight over this ‘green gold.’ “So we see that food isn’t just cultural, it’s also economic and political. It has always been: During Ireland’s Great Hunger, in the mid 1800s, one million people died and one million emigrated because of a potato famine. It was brought on by natural, political, and cultural causes, and permanently changed the country’s political, cultural, and demographic landscape. If this had happened today we’d probably have switched to another staple food if we could. And speaking of switching foods, I don’t think we’ll stop eating meat as a species all together, but it does look like vegetarianism and veganism are ways of the future. At the same time, because food is cultural, it is subject to trends, and changes all the time. Globalization and digital communication have accelerated the process: If you look at food trends from 10 or 20 years ago, you’ll find a strategic push for industrialization — and now people are worried about food that is overprocessed.”

A research article for Proceedings of the National Academy of Sciences of the United States by Michael A. Clark, Marco Springmann, Jason Hill, and David Tilman, found a global shift in dietary choices that are “negatively affecting both human health and the environment.” These choices are a huge menace to ourselves and our planet, threatening the UN’s Sustainable Development Goals and the Paris Climate Agreement. The article states: “Foods associated with the largest negative environmental impacts — unprocessed and processed red meat — are consistently associated with the largest increases in disease risk. Thus, dietary transitions toward greater consumption of healthier foods would generally improve environmental sustainability, although processed foods high in sugars harm health but can have relatively low environmental impacts.”

Silvertown agrees: “The two biggest issues that come to mind are the environment and obesity. Obesity has increased, not just in western countries—there are very high levels in Egypt as well, for example, and it has tripled globally since 1975. The health implications and spread of obesity means most of the world lives in countries where being overweight and obese kills more people than being underweight. We also need to make food production sustainable to address other types of hazards. So many of our planet’s resources are dedicated to feeding ourselves: Half of our habitable land is used for agriculture, as are 70% of freshwater withdrawals, and food production counts for over a quarter of greenhouse gas emissions. But how are you going to feed a population of 10 billion with equitability, without wrecking the environment?”

Almost one and a half billion tons of food are wasted globally, one third of all we produce for ourselves. The risk here isn’t running out of food, but not being able to intelligently address the question, especially when 822 million people still experience hunger everyday; while the bulk are in developing countries, hunger and hidden hunger (a diet with very scarce vitamins and minerals) are still very present in the wide spectrum of social disparities of the Western world, along with ‘food insecurity’—the uncertainty of where the next meal will come from, which affects more than 40 million Americans, including 12 million children. 

Slivertown adds: “Almost half the bread produced in the United Kingdom is thrown away” Almost one and a half billion tons of food are wasted globally, one third of all that we’re producing for ourselves. Restructuring sustainability in the way we produce, process, and distribute food should happen long before scarcity. “At the same time, we have to be constantly thinking about food security. Take COVID-19: imagine the same thing affecting plants, wheat, or rice. Fortunately, these pathogens don’t tend to affect more than one variety. So we know how to guard against this in food crops, and how not to: Bananas are heavily threatened because the whole crop consists of just a few clones.”

Evidence suggesting the transmission of Covid-19 from bats to man, through the intermediary action of pangolins in Chinese food markets, is just a recent example of the overlapping reverberations that stem from the things we put in our mouths. And this feels inevitable—food, not substance, is truly anthropological. The way we handle its gaps and issues will shape the future. Possible visions are personified by people like Marcio Barradas, founder of Food Ink, the first restaurant serving 3D printed food on 3D printed cutlery in London, and Moodbytes, a food design firm in Barcelona, specialized in creating relationships among edibles and new technologies. 

Applying blockchain technology to food means tackling issues such as food fraud, safety recalls, supply chain inefficiency and food traceability, this last aspect being especially important for NGOs and charities — it would allow people to know exactly how much donor money is going where, and to whom. It could also potentially balance market access: Food prices in supermarkets are still the end result of various stages of personal judgement by the involved people and companies; blockchain would make verified transactions available to everybody in the supply chain, bringing more transparency to the market. Dole Food Company is aiming to use blockchain food tracing to monitor its three divisions—tropical fruits, fresh vegetables, and other diversified products—by 2025. 

Silvertown says: “Our food will continue to evolve through genetic modification. But in a way, this is nothing new: GMOs are impossible to define in a manner that separates them clearly from the animals and plants we have modified over millennia of domestication. Today, we understand the fundamental mechanisms of photosynthesis enough that we can feasibly improve it through genetic engineering, and this could raise the yield of crop plants. This type of intervention is just one of the many actions needed to balance the future supply and demand of food. And we should not take this power lightly: All forms of plant and animal breeding, including GM, have potentially unintended consequences and risks, and pests can evolve resistance to GM technologies created to defeat them. However, dietary studies suggest that there are many ways to achieve a healthy diet, and only extremes of overdosing are truly harmful, so we should be able to maintain variety. If I’m right, and there is an instinct to share food, we will make the right choices.”

We can aim to create the perfect diet for our genetic structure, going full (concentric) circle: From food modifying our genes as we eat them, to modifying the genes of our food before we even cook it. If we don’t forget ourselves, and our anthropological love for others in growing it, cooking it, placing it on the table, and passing it around, we might get better and better at feeding—and not eating—the whole planet. 

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