It’s impossible to write an article praising fungi without first thanking Kingdom Fungi for getting early humans drunk.
One group of fungi, the yeasts, generates their energy through a process called fermentation. Yeasts take sugar from plants, and break it down into a compound they can use for energy, along with the byproducts carbon dioxide and alcohol.
Humankind’s obsession with alcohol goes back much earlier than was previously believed
Alcohol poisons most microbes. But because yeasts produce so much alcohol, yeasts have evolved to tolerate very high alcohol concentrations. In a swirling vat of fermenting liquid, other harmful microbes perish.
When harmful microbes perish, humans have a better chance at thriving. Around 10,000 years ago, long before humans invented pasteurisation and refrigeration, a drink rich in nutrients but free of disease-causing bacteria was extremely valuable.
In fact, some researchers, such as biomolecular archeologist Patrick McGovern, think early humans started growing and storing grains not because people wanted more bread, but because they wanted more alcohol.
McGovern is the Scientific Director of the Biomolecular Archaeology Project for Cuisine, Fermented Beverages, and Health at the University of Pennsylvania Museum in Philadelphia, US.
He has found humankind’s obsession with alcohol goes back much earlier than was previously believed. He was able to sequence the DNA of yeast from Egyptian wine vases over 5,000 years old. The yeast is an ancestor of today’s modern brewing yeast, Saccharomyces cereviseae.
In China, McGovern found evidence that people brewed alcohol even earlier, over 9,000 years ago, long before the invention of the wheel. Because, priorities.
Mushrooms make their own wind
Yeasts produce ethanol in striking quantities, but mushrooms can create an actual force: wind.
Consider a mushroom as the fungal equivalent to the fruit of a tree. The cap of the mushroom is full of spores, much like a fruit is full of seeds. But unlike a tree, the majority of an individual fungus is hidden underground, usually forming a network that connects multiple fungi together.
It behoves a mushroom to send its spore-children as far away as possible, so the offspring don’t compete with their parent for nutrients, for example. And unlike many tree fruits, only a few animals disperse mushrooms. Instead of relying on others to do their dirty work, mushrooms make use of the tools they have. Their main tool is water.
When it's time to eject their spores, mushrooms release water vapor. The water evaporates, cooling the air immediately surrounding the mushroom. This cooler air is denser than warm air, and so it flows out and away from the mushroom, creating lift. This lift can carry spores up to 4 inches (10 cm) both horizontally and vertically.
Some fungi make zombies
While some fungi produce their own wind, other fungi produce the stuff of nightmares.
In tropical forests around the world, species of the fungal genus Ophiocodyceps infect carpenter ants, landing on the ant and then burrowing into its brain.
And the zombification cycle repeats
But this is no simple brain-siege. In Thailand, for example, Ophiocordyceps unilateralis first causes the ant to walk erratically, eventually plummeting from its normal home in the canopy to the forest floor below. The fungus then directs the ant to traverse up trees a precise number of centimetres, just less than a metre above the ground, where the temperature and humidity are ideal for fungi to thrive.
The fungus can control not only the height the ant travels to, but also the direction the ant faces, which is usually north-northwest. An uninfected ant would normally not bite a leaf, but infected ants do, clamping down on the underside of a leaf, almost always in the very middle of the leaf, where it is strongest. Like something from an science fiction story, the zombie ant bites down at precisely solar noon.
The ant then dies in this unusual position, stiff with postmortem lockjaw due to muscle atrophy from the fungi rapidly growing in its head. For up to two weeks, the ant corpse remains locked to the leaf while the fungus reproduces, eventually raining spores on unsuspecting healthy ants walking below, carrying food to their nests in the canopy.
And the zombification cycle repeats.
The zombie ant fungus Ophiocordyceps has perfected zombification to a science that has inspired both movies and video games, and was recently the topic of a science crowdfunding campaign to determine which genes are important for the fungus to control its host.
Everybody loves a good zombie story, perhaps the zombie-makers most of all.
One fungus accelerates faster than any other organism on Earth
When it comes to maximizing physics to evict their children, fungi leave other life in the dust. Not only can mushrooms generate their own wind, but one poo-dwelling fungus, Pilobolus crystallinus, accelerates faster than a speeding bullet, and faster than any other organism on the planet.
Want to see dung cannon perform relative to man-made weapons?
Pilobolus isn’t shaped like a typical mushroom. It’s reminiscent of a tiny, translucent snake sporting a sort of wonky bowler hat. The rimless hat is actually a sac of spores. Unsurprisingly, Pilobolus is also known as the hat-thrower fungus, because it ‘throws’ its spore-filled ‘hat.’
And it throws its hat fast. The maximum speed of the hat is about 25 metres per second, while the acceleration reaches 1.7 million m/s2. For comparison, the human-made Saturn V rocket that launched the Apollo 8 mission into space never reached acceleration over 40m/s2.
Want to see the dung cannon perform relative to man-made weapons? The folks over at Earth Unplugged filmed a fantastic video comparing the acceleration of various different guns compared to Pilobolus (see above).
Spoiler: Pilobolus accelerates faster than all the guns.
Fungi can have over 28,000 sexes
If you’ve ever agonised over finding that perfect partner among a sea of mediocre potential love matches, take solace. Life could be much more complicated: you could be a split gill fungus, hunting for a mate.
Granted, some fungi are fairly tame in the bedroom. Yeasts have only two sexes, controlled by two sex genes called, say, gene 1 and gene 2. A type 1 yeast is compatible with all type 2 yeasts, or half the population.
The drawback of a simple two-gene system is that an individual is also sexually compatible with half its siblings. If a sibling is the only compatible fungus nearby, the two can hook up, but their children will lack genetic diversity.
We find the opposite approach in the split gill fungus, Schizophyllum commune. In this widespread species, each sex gene can have hundreds of versions. In order to be sexually compatible, an individual must find a mate that has different versions of both genes. In other words, the mate has to be the opposite ‘sex’ at every gene in order to do the deed.
All these different sexes, up to 28,000 of them, might seem unnecessary, but the higher number of combinations helps keep genes shuffled in case of a new threat. Threats can be environmental such as drought or fire, or biological. Such as parasites.
Parasites on fungi can result in rare delicacies such as the Lobster mushroom, Hypomyces lactifluorum. This parasitic fungus grows on other edible mushrooms, turning them a reddish color similar to a cooked lobster. The resulting FrankenFungus may look strange, but is considered a delicacy that sells for over $20 a pound.
The largest living thing on Earth is a fungus
Last but far from least, fungi also outcompete other living things in terms of their epic proportions. A single individual fungus in Oregon spans 3.7 square miles, and is between 1,900 and 8,650 years old. This truly humongous fungus grew undetected until the 21st century, however.
Fungi such as the honey mushroom, Armilaria solidipes, grow mostly underground. This particular species is a tree parasite, causing white rot root disease on living trees and growing as a tube-like form called a hypha. The hyphae grow and branch to form an underground network, connecting roots between multiple trees.
We only see mushrooms breach the surface when the fungus reproduces sexually. If a fungus never has sex, we might not know it’s there.
Scientists were only able to discover that the honey mushroom can grow to such extensive sizes with the advent of new technology to sequence DNA from multiple mushrooms, and finding that the mushrooms were all genetically identical.
Using this same DNA sequencing approach, scientists have also begun to sequence communities of microscopic fungi living in soil and water, inside plants and animals, and even in the air itself. The rate at which scientists find unique fungal DNA has raised the estimate of the total number of fungi on Earth to upwards of 5 million species.
All these undiscovered species beg the question, what other fascinating feats might these furtive fungi be hiding?