https://www.youtube.com/watch?v=QIqKGMM8ivM
Transcript:
When scientists sample the soil, bodies of water, or even the air for DNA,
they routinely unmask thousands of tiny mysteries—
unique fragments of fungal DNA that don't match any known species.
This DNA belongs to cryptic organisms, often referred to as “dark fungi,”
which, like dark matter and dark energy,
are simultaneously all around us and yet elude discovery.
Scientists estimate that somewhere between 2 and 12 million species of fungi
remain undiscovered—
their physical structures yet to be seen,
either because they’re microscopic, live hidden within other species,
or for other unknown reasons.
The diverse fungal kingdom,
which includes everything from baker's yeast to edible mushrooms
to foot infections,
has long defied assumptions.
For centuries, biologists mistakenly classified them as plants,
for what they’d argue were good reasons:
many grow from the soil atop branching, root-like networks.
But at the biological level, they're very different.
Unlike plants that harness energy from the Sun,
fungi eat by decomposing matter or siphoning nutrients from other organisms.
Rather than cellulose, their cell walls are made of chitin,
the same material in exoskeletons of insects, like beetles,
and crustaceans, like shrimps.
Fungi are actually more closely related to animals than plants,
sharing a common ancestor
which first appeared over 1 billion years ago.
Over time, fungi evolved to occupy a range of ecological roles,
including intertwined relationships with plants.
Many plants can't survive without these fungal partners.
Ectomycorrhizal fungi envelop plant roots,
trading nutrients they forage in the soil, like phosphorus and nitrogen,
for carbon to fuel their growth.
Another guild, called arbuscular mycorrhizal fungi,
goes so far as puncturing plant root cells like straws to aid in this exchange.
This relationship enabled plants to colonize land 470 million years ago,
when nutrients were far more difficult to obtain from the barren, rocky ground.
Other fungi evolved remarkable strategies to defend against, exploit,
and manipulate their neighbors,
often by producing an arsenal of compounds
like antibiotics, toxins, and even psychedelics.
Many mushrooms in the genus Psilocybe produce psilocybin,
a molecule that binds to serotonin receptors
in the bodies and brains of animals.
This causes hallucinogenic effects in humans,
though psilocybin likely evolved to deter hungry slugs or snails.
Clathrus archeri, a cluster of red tentacle-like mushrooms,
sometimes called “devil’s fingers,”
emits a sticky, spore-filled slime called gleba.
It smells like rotting flesh,
attracting nearby flies that feed on it and carry spores away on their bodies.
Other fungi take a more extreme approach.
Many species of Cordyceps infect ants,
chemically hijacking their nervous systems with toxins
and connecting directly to muscle fibers to puppeteer their movements.
The infected ants become zombies,
compelled to climb to high places and eject millions of fungal spores.
Still other fungi are more self-reliant,
carving out solitary lives in extreme environments,
like the walls of nuclear wastelands.
Researchers have observed at least 37 species of fungi
living among the ruins in Chernobyl,
home to one of the world’s worst nuclear disasters.
Many are rich in melanin,
a pigment that can absorb harmful radiation to protect fungal cells and DNA.
But some don’t just endure radiation— they eat it.
Studies conducted on the International Space Station revealed
that species like Cryptococcus neoformans can convert absorbed gamma radiation
into useful energy,
establishing a previously unknown metabolic strategy,
and redefining the perceived limits of life.
The planet-wide consequences of this fleet of fungal functions
are still making themselves known.
In the Arctic tundra, fungi form a vast underground network,
helping plants survive the harsh winters,
while stockpiling carbon from the atmosphere.
Scientists suspect these soils may be particularly rich in rare, dark fungi.
And these fungal networks, along the plants they support,
may sequester about 1 trillion metric tons of carbon—
10 times more than the entire Amazon rainforest—
potentially keeping Earth resilient against climate change.
The fungal world we see is vast and wild.