Or manmade usually means copying from mother nature
Agriculture was supposed to be a very important milestone for humans. It allowed less people to be employed in food production as a farmer can produce more food than he or she can consume. Once people started farming, cities (of non-farming workers) could be formed.
It turned out that humans were not the first species to discover how to farm. Ants farm (Pun intended). When I was young, I heard only about how ants knew how to milk the aphids. The story turned out to be more complex. First, the ants needed a method to muster the aphids in a common area. Once in the aphid farm, the aphids are drugged. Some have their wings removed so that they cannot escape. Naturally, the plant will be overgrazed due to the aphids attacking it. When that happens, the ants will move them to a new plant.
Once the aphids are unproductive, they are eaten. Until that day happens, the ants will protect their livestock. They will remove all the dead and dying aphids to prevent diseases. In some cases, the ants even stock up aphids over winter. Some aphids are even dependent on the ants to excrete waste. Talk about livestock husbandry.
Some ants farm underground. Some of the aphids are carried back underground to be farmed. Then there are ants that farm mushrooms. The leafcutter ants do not eat leaves. The leaves (and other plant parts) are used as food for the fungus. The ants also have to remove pest and mold. They also produce an antimicrobial. In case you are wondering what the difference between antimicrobial and antibiotics, antibiotics are antimicrobial that only kills bacteria. Antimicrobial includes disinfectant, antifungal and other microorganism killing or inhabiting chemical.
The fungus that the leafcutter ant feeds on is not found in the wild. The antimicrobial that is on the ant? It is actually a bacterium that is also not found in the wild. Finally, the fungus that the bacterium kills is also not found in the wild. This means that when a new virgin queen takes some food fungus, bacterium and weed fungus spores also hitch a ride.
There is a difference between the leafcutter ant queen’s duty and a normal queen ant duty. Before any of the workers ants have fully pupated, the leafcutter ant queen must start her fungus farm, maintain the farm while babysitting the eggs or larva. She does not eat the fungus until the worker ants start farming.
This is where the story takes a darker turn. The leafcutter queen ant eats her own eggs. Nobody said farming is easy. The other thing is that ants will still be ants. This means while leafcutter ants eat the fungus they farm, they are not above raiding other colonies or invading them. Finally, there is a species of ants that gather fungus in the wild. This means that the job of mushroom foraging is also taken.
Welcome to the club
Ants are not the only mushroom farmers. Ambrosia beetles also farm. First, they drill a hole in the wood. The wood waste is dumped outside the hole. Then the spores which were from their first home is sowed. The beetles then eat the mushroom harvest. Then we have another farmer, termites. There are two types of termites. The higher termites eat almost any organic material on the jungle floor and underneath it. The lower termites are supposed to be more selective in their diet. They eat wood but it is less nutritious. They also infect wood with fungus to get more protein.
Some of these termites are so specialized that they literally farm the fungus. Worker termites collect fungus spores back to their chamber. They then bring other plant material for the fungus to use. The fungus then grows throughout the nest. The spores pass out undamaged by the termites. One interesting thing is that the fungus also forms a barrier so that predators have a harder time attacking the termites.
Being there, done that
But what about aqua culture? Surely, nobody has farmed the ocean? The damselfish eats only some types of algae. As such, it needs a stable supply of algae. Hence the farming. Invasive species are weeded out. Some damselfish only grow one single crop. Others have a more varied diet. The damselfish also brings edible algae to their farm to be planted. The longfin damselfish goes a step further. It has been observed to domesticate mysid shrimp by using the shrimps to fertilize the algae crop.
Apparently farming is so easy that even slugs have joined the business. There is a marine snail that damages certain plants. Those wounds will then allow fungus to grow which the snail in turn eats. It also fertilizes the wounds on the plants with its waste. For skeptics who think that the snail could be eating the plant as well, all juvenile snails on undamaged plants usually starve.
Before you think that fungus is the bottom of the food chain, it turns out that some fungi also eat animals.