(Picture courtesy of the BBC)

Are Fungi Really Farming Us? 

Fungi have been on earth for around a billion years (compared with humans, who are have been here for around 0.25% of that time).  Some researchers have suggested that fungi might have been farming animals - including humans - throughout history, despite us feeling like we're in the driving seat. In this article, we'll take a closer look at the evidence and explore the fungal effect on humans and other animals.

The Case for Fungi Farming

At the heart of the idea that fungi are farming humans and animals is the concept of manipulation. Fungi have a remarkable ability to manipulate their environment and hosts to suit their needs. For example, when an ant comes into contact with the spores of the Ophiocordyceps fungus, the spores will germinate, grow into the ant's exoskeleton and invade its body (See pictures above and below, courtesy of the BBC). The fungus then begins to manipulate the behaviour of the ant, causing it to leave its nest and climb to a specific location in the forest canopy, where it will bite down on a leaf or stem and remain motionless until it dies. This is known as the "death grip" behaviour, as the ant is essentially locked into position, providing a stable platform for the fungus to grow and release its spores (Hughes et al., 2011).

(Picture courtesy of the BBC)

Once the ant (or other insect) has died, the fungus continues to grow inside its body, using its tissues as a source of nutrients. Eventually, the fungus will produce a fruiting body that emerges from the ant's body and releases its spores, which can infect other ants and continue the cycle of infection and manipulation. Other insects are not safe either.  You can see this for yourself courtesy of David Attenborough here.

The Human Farm?

But it's not just insects that fungi are believed to be manipulating. Some researchers have suggested that certain species of fungi may be responsible for some of our most common food cravings. For example, the yeast Candida albicans produces compounds that mimic the taste of sugar, leading us to crave more sugary foods that provide the yeast with a source of nutrition (Richardson et al., 2018). So are our guts just an elaborate sugar farm for a fungus party?

(The Candida Albicans fungus, Courtesy of Vader1941 at English Wikipedia

Another example is the fungus Aspergillus fumigatus, which can cause a range of respiratory problems in humans. Researchers have suggested that this fungus may be manipulating our immune systems to its advantage, suppressing the immune response to ensure its own survival and spread (Stanzani et al., 2016).

The Magic Mushroom Farm?

Psilocybin-containing mushrooms, such as Psilocybe cubensis, have been used by humans for thousands of years for their hallucinogenic effects - and potentially our ape ancestors did so during our evolution, too.  There are suggestions that the perception-change caused by these mushrooms is part of a bigger picture in the evolution of consciousness (Check out Terrence McKenna talking about his "Stoned Ape Theory" here).

Why did mushrooms evolve to contain this compound? psilocybin could be beneficial to the mushroom, as it could lead to increased dispersal of spores by humans or animals who are under the influence of the mushroom. In the modern world, 'magic mushroom' species thrive as they are nurtured and cultivated in laboratories and bedrooms across the land.  But who's farming who? 

(A shot from my video course Growing Mushrooms Under Your Bed)

The Bottom Line

So, are fungi really farming us? While the evidence is not conclusive, there is certainly cause for further investigation. Fungi have a remarkable ability to manipulate their environment and hosts, although modern science has barely scratched the surface of the inner-workings of the fungal kingdom, and there is still much we have yet to discover.