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Fungi – The Hidden Kingdom · Talking Science

0:00
I want you to picture yourself standing in your
0:03
kitchen. Okay. You've got a cutting board out,
0:05
a chef's knife in your hand, and you are just,
0:08
you know... Slicing up a simple everyday button
0:11
mushroom for dinner. Right. Just a totally standard
0:14
weeknight meal. Exactly. You probably don't think
0:16
twice about it. Maybe you're going to toss it
0:17
into a pan with some garlic and butter. But what
0:20
you are looking at right there on your chopping
0:22
board is basically a biological illusion. Oh,
0:25
absolutely. It is a massive trick of perspective.
0:27
It really is because thinking that mushroom is
0:30
the whole organism. is a bit like trying to understand
0:34
an entire apple tree by staring at a single disconnected
0:38
apple just sitting on a table. We see this little
0:41
umbrella -shaped thing popping out of the dirt.
0:43
And we just assume that's the whole story. When
0:46
in reality, the mushroom itself is just a tiny
0:48
temporary structure. Yeah. The actual organism
0:52
it belongs to could be spreading out directly
0:55
beneath your feet or threading through a rotting
0:58
log in your backyard as this vast, completely
1:01
invisible network. So today, our mission in this
1:05
deep dive is to uncover that network. We are
1:08
venturing into the hidden. completely bizarre
1:11
and ecologically essential kingdom of fungi and
1:16
uh kingdom is really the crucial word to start
1:18
with there yeah definitely we are talking about
1:20
a category of life that is completely distinct
1:23
from plants and animals yet intricately tied
1:26
to the survival of both By the time we finish
1:29
unpacking the sources we've gathered today, the
1:31
way you view a walk in the woods or a loaf of
1:34
bread or even just a fallen tree, it's going
1:37
to be completely reframed. To understand how
1:39
we've so deeply misjudged the mushroom, I feel
1:42
like we first have to unlearn what a lot of us
1:44
absorbed in grade school. Oh, for sure. For the
1:46
longest time, biologists just lumped fungi in
1:49
with plants. And the logic was, well, completely
1:52
superficial. It was literally just they grow
1:54
in the dirt and they don't move. Right. You look
1:56
at a forest. You see plants growing out of the
1:58
dirt. You see mushrooms growing out of the dirt.
1:59
Neither of them is walking around. So they must
2:01
be related. That was the assumption for centuries.
2:04
But when modern biologists actually started looking
2:08
at things on the cellular and genetic level,
2:10
they realized fungi absolutely demand their own
2:14
entirely separate branch on the tree of life.
2:17
Right. Take how they get their energy, for example.
2:20
We know plants are autotrophs. They are essentially,
2:23
you know. solar -powered sugar factories. Using
2:26
chlorophyll. Exactly. Fungi are playing a completely
2:29
different game. Yeah. They have zero chlorophyll.
2:31
They cannot photosynthesize at all. Wow. Yeah,
2:34
they are heterotrophs, meaning they have to find
2:37
and consume their food from their environment,
2:39
which ironically makes them a lot more like us.
2:42
Yeah, they are much closer to animals than plants,
2:44
but they handle the actual eating part in a way
2:47
that is incredibly alien to how an animal operates.
2:50
Alien's a good word for it. I mean, animals like
2:53
us, We eat our food, put it in our stomachs,
2:56
and digest it internally. Fungi do the exact
2:58
opposite. They are digesting their food externally.
3:01
It is a highly effective, if slightly disturbing,
3:04
way to live. I've always thought of it like this.
3:06
Imagine sitting down at a restaurant. Someone
3:08
hands you a pizza, and instead of picking up
3:11
a slice and taking a bite, you just throw all
3:14
of your stomach acid onto the pizza right there
3:16
on the table. Gross, but accurate. You sit back,
3:19
let it completely dissolve into a puddle of raw,
3:22
simple molecules. And then you just soak it up
3:25
like a sponge directly through your skin. That
3:27
is basically the fungal lifestyle in a nutshell.
3:30
They secrete these incredibly powerful enzymes
3:33
directly into their environment. Right. These
3:36
biological chemicals break down complex materials,
3:38
whether that's a dead leaf, a fallen tree or
3:41
an insect. And then the fungus just absorbs those
3:45
raw nutrients. right through its cell walls.
3:47
And those cell walls are another major departure
3:50
from the plant world, right? Because plant structure
3:52
relies heavily on cellulose. Yeah, exactly. But
3:54
fungal cell walls are built largely from a tough,
3:57
fibrous substance called chitin. Which is the
3:59
exact same material that makes up the hard exoskeletons
4:02
of insects and crustaceans. So that little mushroom
4:05
on your cutting board actually has more in common
4:07
structurally with a crab shell or a beetle than
4:10
it does with a carrot. It's wild to think about.
4:12
And that shared use of chitin combined with that
4:15
heterotrophic need to consume other organic matter,
4:18
is why genetic studies now place fungi closer
4:22
to animals on the evolutionary tree. We're practically
4:24
family. Well, distant cousins. They share a more
4:28
recent common ancestor with animals than either
4:30
group shares with plants. Okay, so... Knowing
4:33
that the mushroom isn't the main body, we have
4:35
to look at what's actually doing all this external
4:38
digestion underground. The basic building block
4:41
is something called a hypha or hyphae in the
4:44
plural. Yes. I've seen these under a microscope
4:47
and they just look like these incredibly thin
4:49
thread -like filaments. They do. And they grow
4:53
by extending at their tips. building up internal
4:57
fluid pressure to physically push their way through
4:59
soil, wood, or whatever substrate they're living
5:02
in. Like tiny microscopic drills. Exactly. And
5:05
as they push forward, they branch repeatedly.
5:07
When you get a dense, tangled, sprawling mass
5:10
of these microscopically thin hyphae, that is
5:12
called a mycelium. The mycelium. Right. The mycelium
5:15
is the true body of the fungus. It's the trunk,
5:18
branches, leaves, and roots of a tree, all rolled
5:22
into one diffuse, spreading... invisible network.
5:26
And the sheer physical scale of a mycelium can
5:28
be mind -boggling. Our sources highlight a perfect
5:31
example in the Malheur National Forest in Oregon.
5:34
Oh, the humongous fungus. Yes. There is a single
5:37
individual fungus, a species called Armillaria
5:40
astoyae. When researchers started mapping it
5:43
by testing the DNA of samples across the forest,
5:45
they found that this one single genetic individual
5:48
spans several square kilometers. It's unbelievable.
5:51
And scientists estimate it is at least a couple
5:53
of thousand years old. It's one of the largest
5:55
and oldest known living organisms on Earth. It
5:59
has just been quietly branching, digesting, and
6:02
spreading through the root systems of that forest
6:04
since before the Roman Empire existed. That kind
6:07
of longevity raises a fascinating question, though.
6:09
What's that? Well, if you have this sprawling,
6:12
invisible network that can successfully digest
6:14
food underground for thousands of years, why
6:16
on Earth does it ever bother pushing a mushroom
6:18
up into the light? It seems like a massive waste
6:20
of energy. Ah, right. It's all about reproduction.
6:24
The mushrooms we see are what mycologists call
6:27
fruiting bodies. They are temporary, highly energy
6:31
-intensive structures built for one very specific
6:34
purpose, to produce and disperse spores. Which
6:38
are the fungal equivalent of seeds. Exactly.
6:40
When you take a walk through a damp forest after
6:43
a heavy rain and see all those mushrooms popping
6:45
up overnight, you aren't seeing new organisms
6:48
spontaneously generating out of the mud. Right.
6:51
They didn't just appear out of nowhere. No. You
6:53
are seeing a brief, visible signal. from a much
6:56
larger, older, invisible network that is suddenly
6:59
trying to spread its offspring to new locations.
7:01
And the mechanics of how they get those spores
7:04
out into the world are just wild. Oh, they really
7:06
are. If you look at the underside of a standard
7:08
mushroom, you see those thin, blade -like structures
7:11
called gills. They are perfectly engineered to
7:15
drop spores so they catch the absolute slightest
7:17
microcurrents of air. Yeah, the aerodynamics
7:20
are amazing. If you've ever left one of those
7:22
mushrooms on a piece of paper overnight, you
7:24
know you get this beautiful, delicate dust pattern
7:27
called a spore print. But then you look at other
7:29
species, like puffballs, which turn into these
7:33
pressurized sacs triggered by a physical impact.
7:36
Right. Just a single drop of water hitting the
7:38
outer membrane of a mature puffball forces a
7:41
sudden, visible cloud of fine spore powder into
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the air. It's using the kinetic energy of the
7:47
rain itself. Wow. Or you have the ones that deliberately
7:51
smell terrible to humans. Stinkhorns. Yes. They
7:55
literally mimic the chemical signature of rotting
7:58
meat. That foul odor acts as a lure for flies
8:01
and beetles, effectively enlisting insects as
8:03
biological couriers to carry the sticky spores
8:06
away on their legs. It's clever, even if it is
8:08
gross. And there are even species that act like
8:10
built -in cannons. Wait, cannons? Yeah, like
8:13
Pylobulus, which builds up extreme internal fluid
8:16
pressure in a specialized stock and physically
8:18
fires its store capsule at massive accelerations
8:21
over surprising distances. The engineering is
8:24
incredible. It is, but it all comes down to evolutionary
8:26
survival and the brutal reality of competition.
8:29
Makes sense. If a fungus just drops its spores
8:31
exactly where it is already living, those microscopic
8:35
offspring are going to be competing with their
8:37
massive, highly efficient parent network for
8:40
the exact same nutrients. Oh, so they just starve.
8:43
Pretty much. So the underlying goal of all these
8:46
bizarre mechanisms, the cannons, the smells,
8:49
the puffballs, the aerodynamic kills, is to escape
8:52
the parent network. If they can get those spores
8:54
far enough away, they might establish a new colony
8:57
in fresh territory with zero competition. Okay,
9:00
so what actually happens when those spores land
9:03
in that fresh territory? Assuming they survive
9:06
and start sprouting their own hyphae, they get
9:08
to work on what is probably the most unglamorous
9:10
but arguably the most essential job on planet
9:13
Earth, eating dead things. Right. Decomposition
9:16
sounds simple. a bit morbid maybe, but it is
9:19
an ecologically critical process. Totally. When
9:21
a massive tree falls or an animal dies in the
9:23
woods, all the energy and nutrients, the carbon,
9:26
the nitrogen, the phosphorus, are locked up inside
9:29
extremely complex, tightly bound molecules. And
9:32
something has to unlock them. Exactly. Something
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has to break those molecular bonds apart before
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the rest of the ecosystem can reuse those raw
9:40
materials. Fungi are the ultimate biological
9:43
recycling system. Our sources specifically highlight
9:46
a group called white rot fungi. They are among
9:49
the only organisms on Earth that can efficiently
9:51
break down a substance called lignin, as well
9:54
as cellulose. And lignin is a big deal. It's
9:57
the highly rigid structural compound that gives
10:00
wood its strength and makes it essentially waterproof.
10:02
Right. It is a chaotic, complex polymer. Bacteria,
10:06
for the most part, are terrible at breaking down
10:08
lignin because it doesn't have a simple repeating
10:10
structure that bacterial enzymes can easily snap
10:13
apart. To put this in perspective, think of lignin
10:16
as the steel rebar hidden inside the concrete
10:19
walls of a building. That's a great way to look
10:21
at it. It is incredibly tough. You can chip away
10:23
at the concrete all you want, but until you cut
10:26
the rebar, the structure stands. Fungi have evolved
10:28
the biological blowtorches necessary to melt
10:31
that rebar. They release these highly reactive
10:34
oxygen compounds that just blast the lignin apart.
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Without fungi doing this, forests would literally
10:40
choke to death. They really would. We would be
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buried under miles of undemolished... dead tree
10:45
trunks. All those nutrients would stay locked
10:49
away in dead wood forever, completely unavailable
10:52
to the next generation of plants and insects.
10:55
There was actually a period in Earth's history,
10:57
the Carboniferous Period, before white rot fungi
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had fully evolved the ability to break down lignin.
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Wait, really? What happened? Dead trees just
11:06
piled up for millions of years. They didn't rot.
11:09
They were eventually compressed into the coal
11:11
deposits we mine today. Wow. That is what a world
11:14
without these fungal blowtorches looks like.
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They quietly return the raw materials of life
11:18
back into the carbon cycle. It's easy to look
11:21
at that decomposition and think fungi only deal
11:23
with death and decay, but their most profound
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impact is actually how they sustain the living
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through these silent, highly complex partnerships.
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Ah, you're talking about my Cariza. Word comes
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from Greek roots, meaning fungus root. It is
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a symbiotic partnership, a mutually beneficial
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relationship between a fungus and the roots of
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a living plant. How does it work physically?
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The fungal hyphae will wrap around the plant's
11:48
roots, or in many cases, physically penetrate
11:51
the root cells to create a direct interface for
11:53
exchanging nutrients. They set up an incredibly
11:56
efficient biological trade agreement. The fungus
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acts like a massive, highly sensitive extension
12:02
of the plant's root system. Right. Because fungal
12:05
threads are so microscopically fine, they can
12:08
weave through the tiniest pores in the soil to
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scavenge scarce resources like phosphorus and
12:13
nitrogen way better than the plant's thick roots
12:15
ever could. Much better. It delivers those minerals
12:18
directly into the plant's cells. In return, the
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plant hands over sugars that it makes through
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photosynthesis. Sugars the fungus desperately
12:25
needs for energy, but, like we said earlier,
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can't. not make itself. And this isn't some rare
12:30
biological anomaly either. The vast majority
12:32
of land plants on Earth form these mycorrhizal
12:35
partnerships. In fact, evolutionary biologists
12:38
believe this exact relationship was crucial in
12:41
helping plants first colonize dry land hundreds
12:45
of millions of years ago. Because the soil was
12:47
so bad. Exactly. Back then, the soil was incredibly
12:50
harsh and nutrient poor. Plants just couldn't
12:53
have survived the transition from the oceans
12:54
without fungal partners mining the rock and soil
12:57
for them. Which brings us to a topic that has
13:00
totally captured the public imagination recently.
13:02
The wood wide web. Oh, yes. This is the pop science
13:06
idea that there is this vast forest Internet
13:10
where trees are whispering to each other through
13:12
fungal connections, actively warning each other
13:15
of danger and purposefully sending carbon care
13:17
packages to their favorite saplings. It's everywhere
13:20
right now. I admit I love this idea. It makes
13:22
the forest feel like a single conscious community.
13:25
It is a beautiful, deeply romantic narrative,
13:28
and you see it heavily promoted in documentaries
13:30
and bestselling books. But if we look closely
13:34
at how the scientific method operates, we have
13:36
to evaluate the actual evidence. Right. What
13:38
does the science actually say? A highly regarded
13:40
2023 review in a leading ecology journal took
13:45
a hard look at this entire concept. Now, the
13:48
foundational research from the 1990s does show
13:50
that under experimental conditions, carbon and
13:53
resources can move between plants that are connected
13:56
by a shared fungal network. Okay, so the pipes
13:59
exist and things move through them. What's the
14:01
problem? The problem is that the idea of conscious
14:04
cooperation, a forest internet where trees are
14:07
actively, intentionally communicating and nurturing
14:09
each other. has vastly outpaced the actual evidence.
14:14
The 2023 review pointed out that those dramatic
14:17
claims rest on a very small number of studies.
14:20
Some of those had methodological limits or were
14:23
conducted in highly controlled greenhouses. Not
14:25
exactly a natural forest. Right. And those specific
14:27
findings were just amplified and exaggerated
14:29
over and over in the media. We have to distinguish
14:32
between... Resources occasionally move passively
14:34
through a shared root fungus because of pressure
14:37
gradients. And trees are purposefully talking
14:39
to each other to save their friends. I hear that,
14:41
but let me challenge the scientific purism for
14:43
a second. Is it really that detrimental to overhype
14:46
the forest internet a little bit? If romanticizing
14:49
the forest and giving trees a sense of community
14:51
makes the average person care more about conservation
14:54
and protecting these ecosystems, isn't that ultimately
14:58
a net positive for the planet? I mean, I completely
15:00
understand that perspective. We all want people
15:02
to care about forests, but building conservation
15:04
arguments on exciting but scientifically inaccurate
15:08
headlines is incredibly risky. Because if the
15:12
science changes... Exactly. When the science
15:14
inevitably corrects itself, as it is doing now,
15:18
you risk losing credibility with policymakers
15:20
and the public. Nature is miraculous enough based
15:24
purely on the facts. We don't need to anthropomorphize
15:27
trees, you know, assigning them human motives
15:30
and behaviors, to appreciate how vital fungal
15:33
networks are to a forest's survival. Yeah, that
15:35
makes sense. The reality of a complex, competitive,
15:38
and symbiotic ecosystem is far more fascinating
15:40
than a cartoon version of trees talking to each
15:43
other. Fair point. We don't need to invent magic
15:45
when the biology is already pulling off miracles.
15:47
And actually... There's another fungal partnership
15:50
hiding in plain sight that most of us walk past
15:53
every single day without noticing. Lichen. A
15:55
lichen is amazing. I always assumed lichen, you
15:58
know, those crusty green and gray patches you
16:00
see on rocks and branches, was just some kind
16:02
of moss. Most people do. But a lichen is not
16:05
a single organism at all. It is a stable, intimate
16:08
partnership between a fungus and a photosynthetic
16:11
partner, usually an algae or a cyanobacterium.
16:14
It's an incredible division of labor. The fungus
16:17
acts as the housing developer. It provides the
16:20
physical structure, the protection from the elements,
16:23
and it mines minerals from whatever surface it's
16:26
attached to. Yes. And then the algae acts as
16:28
the solar panels, capturing sunlight and providing
16:31
the sugar. Together they form a biological unit
16:34
that is basically invincible. They really are.
16:36
Lichens can survive on bare Antarctic boulders,
16:39
in the scorching deserts, or on the sides of
16:42
brick buildings in heavily polluted cities. Next
16:44
time you walk through your neighborhood, just
16:46
look at the tree trunks or the older concrete
16:48
walls. You will almost certainly see them. And
16:51
they grow incredibly slowly, sometimes just fractions
16:54
of a millimeter a year. Wow. And because they
16:57
absorb everything directly from the air around
16:59
them, they are highly sensitive to air pollution,
17:02
specifically sulfur dioxide. Scientists actually
17:05
use them as low -cost biological indicators.
17:08
Oh, that's clever. Yeah. If the lichen on the
17:10
trees in your city is thriving and diverse, your
17:13
local air quality is probably pretty good. If
17:15
they vanish, it's a clear warning sign. It's
17:18
a perfect example of how fungi quietly monitor
17:21
and shape the world around them. And we don't
17:24
even have to look at extreme environments like
17:26
Antarctica or even the trees in our neighborhood
17:28
to see these partnerships at work. Humans have
17:32
been blindly partnering with fungi for thousands
17:34
of years to build human civilization itself.
17:37
Oh, the culinary applications alone have shaped
17:39
human history. We are talking about yeast. Good
17:42
old yeast. Yeast are single -celled fungi. Specifically,
17:45
a species called Saccharomyces cerevisiae. They
17:49
perform a biochemical magic trick called fermentation.
17:51
When yeast find themselves in an environment
17:54
without oxygen, they break down sugars to get
17:56
energy. And as they process that sugar, they
17:59
produce two very important waste byproducts,
18:02
carbon dioxide and ethanol. Think about the bread
18:04
sitting in your pantry right now. Without yeast,
18:07
it would just be a dense, hard brick of cooked
18:10
flour. Very true. It's the carbon dioxide gas
18:13
expelled by the yeast getting trapped in the
18:16
stretchy gluten of the dough that makes the bread
18:18
rise and gives it that airy, soft texture. And
18:22
in beer and wine, it's the ethanol, the alcohol,
18:25
that the yeast leave behind. What is truly profound
18:28
about this is the historical timeline. Humanity
18:31
mastered the production of bread. beer, and wine,
18:34
the literal caloric and cultural cornerstones
18:37
of early human agriculture and society, thousands
18:40
of years before the invention of the microscope.
18:43
We outsourced our food engineering to a hidden
18:45
kingdom of single -celled fungi without even
18:47
knowing we were doing it. We were harnessing
18:49
fungal metabolism millennia before we knew what
18:51
a cell was. But food isn't the only thing they
18:54
engineered for us. Fungi handed us what is arguably
18:56
the most consequential medical discovery of the
18:58
20th century, and it basically came down to a
19:00
guy having bad laboratory hygiene before. going
19:03
on vacation. Ah, yes. The story of penicillin.
19:06
Alexander Fleming, a Scottish scientist working
19:09
at St. Mary's Hospital in London in 1928. What
19:13
exactly did he do? Well... He left some petri
19:15
dishes full of Staphylococcus bacteria sitting
19:17
out on his bench, went away on holiday, and came
19:20
back to find that one of the dishes had been
19:22
contaminated by a stray mold spore floating through
19:25
the air. A literal messy dust accident that ended
19:29
up winning a Nobel Prize. The mold was later
19:31
identified as a species of penicillium. Fleming
19:34
noticed something extraordinary. There was a
19:36
clear, empty ring around the mold where all the
19:39
surrounding bacteria had completely died off.
19:41
So it was fighting back. Yes. The fungus wasn't
19:44
just sitting there. It was actively producing
19:46
and secreting a toxic substance into the gel
19:49
to defend its territory and kill off bacterial
19:51
competitors. Fleming named that chemical weapon
19:53
penicillin. And the mechanism is brilliant. It
19:56
specifically targets how bacteria build their
19:59
cell walls, preventing them from cross -linking
20:01
the structural molecules. The bacteria essentially
20:04
weaken and burst open. open. And because human
20:07
cells don't have cell walls at all, the chemical
20:10
is lethal to the bacteria, but largely harmless
20:12
to us. Which is key. Once other scientists figured
20:15
out how to isolate and mass produce this fungal
20:18
defense mechanism during World War Two, it became
20:20
the world's first widely used antibiotic. It
20:24
completely transformed modern medicine. infections
20:27
from a simple scratch or battlefield wounds or
20:30
minor surgeries that used to be a guaranteed
20:32
death sentence suddenly became completely treatable
20:35
yeah it has saved hundreds of millions of lives
20:38
But looking closely at penicillin raises a really
20:40
vital point about the duality of this kingdom.
20:43
Right, because the exact same chemical mastery
20:46
that allows fungi to destroy bacteria for penicillin
20:49
or the biological blowtorches that allow them
20:51
to melt rigid wood make them a formidable, terrifying
20:54
threat when they turn their attention to living
20:57
creatures. We have to look at the dark side of
20:59
the kingdom. We do. When fungi become agents
21:01
of disease, the ecological damage they inflict
21:04
can be almost apocalyptic. Take the chytrid fungus,
21:08
for example. It's a waterborne fungus that infects
21:11
the skin of frogs and other amphibians. And amphibians
21:14
rely on their skin for everything. They literally
21:16
breathe and drink through it. Exactly. The chytrid
21:19
fungus feeds on the keratin in their skin, causing
21:22
the skin to thicken and harden. It completely
21:24
disrupts their ability to regulate water and
21:27
essential minerals like sodium and potassium,
21:29
essentially causing the frogs to die of cardiac
21:32
arrest. It is currently tearing through ecosystems
21:35
worldwide, causing global amphibian extinctions.
21:38
Biologists recognize it as one of the most damaging
21:40
wildlife diseases ever documented in the history
21:43
of science. And there is white nose syndrome
21:45
caused by a completely different fungus. It infects
21:48
hibernating bats in North America. It grows on
21:51
their muzzles and wings during winter, acting
21:53
as this constant itchy irritant that repeatedly
21:56
wakes the bats up from their deep hibernation.
21:59
Every time they wake up, they burn through their
22:01
critical winter fat reserves, ultimately starving
22:04
or freezing to death before spring arrives. It's
22:07
so sad. has wiped out millions of bats since
22:10
the mid -2000s, devastating populations that
22:12
control agricultural insect pests. And human
22:16
beings are absolutely not immune to fungal threats
22:18
either. We deal with everything from the common
22:21
relatively minor annoyances like Candida yeast
22:24
infections or athlete's foot all the way to severe
22:28
highly lethal aspergillus lung infections. Those
22:31
are particularly dangerous for people whose immune
22:34
systems are compromised by things like chemotherapy
22:36
or organ transplants. And this isn't just a background
22:40
issue anymore. It's becoming a massive public
22:42
health crisis. The World Health Organization
22:44
recently had to publish its first ever list of
22:47
priority fungal pathogens because, just like
22:50
bacteria, fungi are adapting to our medicines.
22:53
That is the real concern, keeping epidemiologists
22:56
awake at night. Dangerous fungal infections have
22:59
historically been vastly under research compared
23:01
to viruses and bacteria. But now, fungi are showing
23:05
clear signs of developing resistance to the very
23:07
limited arsenal of antifungal drugs we have available.
23:10
And developing new ones is incredibly difficult.
23:13
Extremely difficult. Because, as we established
23:15
earlier, fungi are our distant evolutionary cousins.
23:19
Our cells are much more similar to fungal cells
23:22
than they are to bacterial cells. Right. So finding
23:25
a chemical that kills a fungal cell without also
23:27
destroying the human host cells is a massive
23:30
biological puzzle. It's a tragic irony. The very
23:33
kingdom that provided our greatest chemical ally
23:36
in the fight against bacteria is slowly evolving
23:39
into an unstoppable adversary in its own right.
23:42
What makes that evolution so daunting, and quite
23:44
frankly a bit scary, is the sheer scale of what
23:47
we still don't know about them. How much is unknown?
23:50
Well, scientists have formally named and described
23:52
about 150 ,000 species of fungi. But when researchers
23:56
take soil or air samples and sequence the DNA
24:00
they find, they are constantly detecting genetic
24:03
markers for fungi that have never been cataloged,
24:06
never been grown in a lab, and never been seen
24:08
by human eyes. The estimates I saw in the sources
24:11
suggest there are anywhere from two to several
24:13
million species out there. At least. The vast,
24:18
overwhelming majority of fungal life on Earth
24:20
is completely unknown to science. They spend
24:23
their entire lives underground inside the tissues
24:25
of plants or microscopic and airborne, rarely
24:29
or never producing a visible fruiting body. Wow.
24:32
A single patch of dirt in your local park could
24:34
hold dozens of unique species that just quietly
24:37
go about their biochemical business completely
24:39
undocumented. So let's bring this all the way
24:41
back to where we started. You are standing in
24:43
your kitchen, slicing that button mushroom on
24:45
the cutting board. What you are looking at is
24:47
not just a simple vegetable to toss in a pan.
24:50
It is a fleeting, visible wave. Hello from an
24:53
ancient, invisible network. It's a network that
24:56
possesses the biological blowtorches to digest
24:59
the dead and keep the carbon cycle moving. It's
25:02
a network that partnered with plant roots to
25:04
literally green the barren earth that gave humanity
25:08
the gifts of bread, wine and antibiotics. And
25:11
at the very. same time it is a kingdom that poses
25:14
a rising highly complex threat to global health
25:18
and agriculture it really leaves you with something
25:20
to seriously mull over the next time you walk
25:22
through the woods if a single accidental discovery
25:26
of a stray mole on a dirty petri dish in london
25:29
could completely transform human medicine and
25:32
save hundreds of millions of lives that other
25:34
civilization altering miracles or conversely
25:37
what devastating unstoppable pathogens are quietly
25:40
waiting in the millions of fungal species we
25:42
haven't even named yet, spreading silently right
25:45
beneath our feet.