What Can Ants Teach Us About Agriculture?

In a 1794 letter, George Washington said, “I know of no pursuit in which more zeal & important service can be rendered to any country than by improving its agriculture.” While the number of frontier farmers has declined since Washington’s time, agriculture is unquestionably one of humanity’s greatest achievements, establishing the foundation for civilization and allowing the human population to grow tremendously.

Agriculture, on the other hand, isn’t always a human endeavor. Leaf cutter ants, who have a brain the size of a pinhead, have likewise made the change from hunter-gatherers to farmers – and they did so long before humans.

Ants are farmers to the degree that they, along with a few other species, grow their own food for consumption. Over 200 ant species currently foray into the jungle across the Western Hemisphere, motivated by some deep-seated atavistic impulse that pushes them to gather plant debris, which is taken back to the nest to feed fungal crops, which are then fed by the ants.

Fungi Farmers

Ants have been farming diverse fungus in the South American jungle for 60 million years, according to a Smithsonian Institution research published in 2017. The study discovered that 30 million years ago, a divergence occurred within the agricultural ant lineages as a result of certain ant species shifting to drier climates, using genetic data from several ant species.

Agriculture is divided into two sorts by farming ants: upper and bottom agriculture. Lower agriculture, which is common in wet rainforests, allows fungal crops to escape the ant colonies and return to the wild. The ants collect wild mushrooms from time to time to carry back to their colonies. As a result of the mixing of wild and cultivated fungal gene pools, the lower ants have less control over the genetics and evolution of their crops. In essence, the fungus can thrive without them, implying that it is less reliant on ants.

In modern agriculture, neither the ants nor the fungus can survive on their own. According to a Smithsonian news release about the discovery, some ants colonized the new environment outside of the forest some 30 million years ago when the temperature in South America transitioned toward colder, dry grasslands. The fungus, which originated in the rainforest, was unable to escape and flourish in the desert, thereby isolating it as a separate species dependent on ants and unable to survive in the wild. The ants build perfect greenhouses for their crops by digging chambers up to 12 feet deep and altering moisture and air flow.

“If you’ve been carried into a dry habitat, your fate is going to match the fate of the colony you’re in. At that point, you’re bound in a relationship with those ants that you were not bound in when you were in a wet forest,” stated Ted Schultz, entomologist and lead author. 

The fungus became domesticated over time, as it could not thrive in arid areas without the ant’s fungal greenhouse. “As with certain crops that have been so heavily modified by human breeders that they can no longer reproduce and live on their own in the wild, some fungal species have become so completely dependent on their relationship with farming ants that they are never found living independent of their farmers,” Schultz stated.

A Mutual Feeling

The inextricable connection between insect and fungus, on the other hand, is more complicated. When ants became farmers, they lost their capacity to produce arginine, an amino acid. As a result, they were forced to rely on the fungus for that amino acid. In exchange, the ants take care of the fungus by watering, cleaning, and nurturing it. This begs the question: who is the real puppeteer? Have the ants used the fungus to their advantage, or are they the ones being manipulated, toiling tirelessly for amino acids in order to maintain the fungal overlords’ prosperity? Neither is the solution. They’ve created a mutualistic connection in which both species benefit from a synchronized rhythm.

The ant farmers construct complex, climate-controlled subterranean labyrinths and synthesize fungus food with specific nutrients, allowing them to maximize fungal output without jeopardizing the crop’s ability to withstand environmental challenges. Antibiotics are secreted to limit the growth of fungus-threatening pathogens, and they evolve in tandem with the local ecology to accomplish comparable checks and balances. Their agriculture produces all of the food that their cultures require at a size and efficiency that is comparable to human agriculture. All of this ensures a reliable food supply without wreaking havoc on the environment.

Compare this to other current agricultural techniques, such as clearing forests, using steel tractors, and using chemical pesticides at the price of biodiversity and environmental health. While humans can’t precisely reproduce ant farming’s blueprints, we can learn to live in harmony with other species and engage in more environmentally friendly agricultural activities. In the end, we want to be able to support the world’s rapidly growing human population without leaving a trail of contaminated ecosystems and deforested wastelands behind us.

Source: “What Ants Can Teach Humans about Farming” by Discover Magazine