Symbiotic Relationships: Nature’s Most Unique Partnerships

In this episode of Wildly Curious (formerly For the Love of Nature), co-hosts Katy Reiss and Laura Fawks Lapole explore the fascinating world of symbiotic relationships. From the mutualistic bonds that benefit both species, to the parasitic ties that favor one at the expense of another, they dive deep into the intricacies of nature’s partnerships. With examples ranging from mistletoe’s parasitic connection to bird’s nest ferns fostering mini-ecosystems, Katy and Laura bring humor and insight into these critical ecological interactions. Get ready to see how nature thrives through cooperation and competition!

Perfect for nature enthusiasts, science lovers, and anyone curious about the hidden relationships in the natural world. Join us for an enlightening and fun discussion on the symbiotic secrets of the wild!

Transcript

Hello, and welcome to For the Love of Nature, a podcast where we tell you everything you need to know about nature and probably more than you wanted to know. I'm Laura.
And I'm Katy. And today we are talking about symbiotic relationships.
Yeah.
What's a symbiotic relationship, Laura?
Well, Katy, it is one that, it's basically the association between two species that live together. So a lot of people who hear symbiotic relationships think that it's gotta be good things, but that's not necessarily true, because today we're going to talk about how many species have developed close relationships with one another, some of which benefit both, and others that do not.
So you really default to that that would be good? Because every time I hear that, I always assume it would be bad. Maybe this is like a glass half empty kind of situation.
Yeah, it must be, yeah. Well, and where I was reading on the internet, people were like, oh yeah, symbiotic relationships, good thing.
Huh, interesting.
And your legs, yeah. Working together is always bad.
Right, always horrible. Maybe it's the divorce, that my brain is just like being with somebody. No, no.
Yeah, right, can't, can't, no.
Meanwhile, I'm like working in tandem.
Yeah, it's great. Well, there are five different main types of symbiotic relationships. You have mutualism, okay.
The kind that I'm thinking about. Commensal, it's like pencil.
Commensalism, predation, parasitism, and competition. Which some of those fall under other ones. It depends on your source.
Plus everyone's like, what the heck is commensalism? That's when one benefits and the other one's not affected. Right, so mutual both commensal, one not anything to the other, parasite, one good, one bad, predation, eating.
And what was the other one?
Competition. Yeah, which I don't know, predation and competition sound weird to me. Well, we'll get into it.
All right, I know Laura, you have nature news.
Yes, I do. And it tracked back to a couple, I don't know if it was the last season, the season before. We talked about like terribly named things.
It was AC's episode.
Oh, that's right, that's right.
So, in that episode, we talked about an animal with a non-PC name that should be renamed and was being renamed. It was the gypsy moth. And in that episode, I said that what it should be called was the destroyer moth.
The destroyer, yes.
That's a scientific name.
Yes, and it's badass, so why not?
Right. So, nature news is they finally decided on a name, and it is insanely disappointing, because the name is the spongy moth.
The spongy moth?
Spongy.
And that's so not intimidating.
That was decided upon by a group of 57 people of diverse backgrounds.
And that's the best they could come up with. That's the best 57 people could come up with.
And 200 names were suggested. I didn't send mine in. I'm really hoping somebody else did.
But that's the name they decided on.
That is their first mistake, is asking the public. Having worked in zoos, that's one, that's how you end up with Boaty McBoatface. You just never ask the public.
Never.
No.
At the water utility that I work with, we did a naming competition, and I was a strong advocate for saying, guys, I promise you, nothing good is gonna come out of this. Because we got a new mascot, new costume, and they were like, let's do it, let's name it. And I was-
Well, no, okay, so shout out, I think it's DC Water. Their mascot is a water drop, same thing as ours. And its name is Wayne.
Wayne, the water drop.
Because it's a Wayne drop, get it?
Oh, got it.
And so I'm like, I was like, yeah, I was like, its name is Wayne. And so, you know, surface face value, you don't think too much about it. And then you say, oh, Wayne, the drop, Wayne, oh, Wayne drop.
It's really good. And so I was like, guys, we can think of something creative, something, and we think of creative stuff all the time. That's our job.
But we know, they want, they insisted on opening up to a naming competition. And these employees are no longer working here, so I can bash them all I want. No, I won't.
But I strongly advocated. I'm like, guys, this is a bad idea. Take it for somebody who's worked in zoos for years.
Nothing good comes out of it. Even pulled up the Boaty McBoat face example. Nope.
So now our mascot's name is Splash, which is to me, just very me.
That's how I feel about the Spongy Moth. Yeah. Well, so apparently, so right, the mistake, I mean, 57 people had to agree on it.
That's way too many people.
The only reason that apparently, so it's called the Spongy Moth because it refers to the egg masses of the species. Which is so gross.
And gross. But also, yeah. Out of everything, it could be named after.
Right, let's name it after its spongy eggs. But at least, this is a little bit of justification. Apparently, in other languages and countries, it is called basically the Spongy Moth.
So in France and in Canada, it's known as la Spongyous. And in Turkey, its name translates.
Wait, sponge juice?
A spongy, I don't know. How do you say sponge in French? Spongyous, spongyous, I don't know.
Totally sounds like sponge juice, which is so disgusting.
And in Turkey, its name translates to sponge knitter, and in Germany, it's sponge spinner. So sponge spinner, because it's like laying its egg sack. It's spinning the sponge of the egg mass.
So gross.
Yeah, this is just getting worse. The more that we-
This is definitely better. The sponge, I guess-
The sponge. That sounds like a sign from that episode.
Sponge spinner. I think that-
Sponge knitter?
The only good thing that can come from this is that it will make people aware of their disgusting spongy egg masses, and maybe then people will pick them off of trees.
But even so, okay, I would never, if somebody's like, oh, the sponge moth, I would think like, oh, the moth must be spongy. Like, is it squishy? Like, that would totally make me-
Is it squishy?
That would totally make me want to go touch it. Like, I said, there's Katy running through the forest trying to squish a spongy moth.
Squish it.
Yeah, yeah, actually smash it.
Yeah, is it squishy? I would guess squish it. So yeah, spongy moth, lame, but at least it's better than its former name.
Yeah, still the destroyer moth would have been-
Way better.
Would have been way better. All right, do we want to jump into these symbiotic? Listen, I am so excited, because one of these is, okay, you think I love trees?
No, listen, I know which one.
No, no, no, no, you think you know, but there are some, so it's not the one that we both picked, that you said that you knew I would pick. I am talking about that one, but there is one that I love. It was so much more than that.
Whoa.
Yeah.
Because, so as you guys know-
Get excited, people.
We send our ideas to Kim to make sure that we don't have the same one, but that Katy and I don't know what we have. But every once in a while, we do choose the same thing, or I'm like, I would love to do this, but I know that Katy's gonna want to. And I had some other ideas in mind, so I was like, listen, if she doesn't want it, I'll take it, but I know she's gonna ask.
Yeah, I definitely took it. I definitely took it. But it's the same thing with you.
Anytime we're doing an episode where big cats can be mentioned, I just, or bears, I just stay away from them.
But it's essential that this, if we meet, someone needed to talk about it, so I couldn't take the risk.
Oh yes, absolutely.
So that's why I was like Kim, if she doesn't.
But there's one that I love even more.
All right, well, I'm really excited. You go first.
No, go ahead, go first.
All right.
Build up the suspense.
I asked Kim to help me narrow down mine. So I have one positive relationship and one negative relationship. We'll start with the negative, since that's your go-to anyway.
I'm not big on relationships right now.
And ironically, this one is really fitting for your parasitic relationship.
Okay, to be clear, to be clear, I will say my ex-husband is not a parasite. Just to clear the air, it's just funny. We're just joking because I just got a divorce.
It's just funny right now.
And your ex-husband has had some really good, I mean, helped us a lot at the beginning.
Oh, yeah, for sure. Definitely for sure. He was my source of doing it just because I didn't, and I always forgot, so.
Yeah, we, yeah, no, just funny.
It is just funny.
But what's extra funny is that this does have to, like, when you think of this-
I'm just gonna keep making-
You think about love.
I'm gonna keep making divorce jokes. Go ahead. During the song.
It's mistletoe.
Oh, really? Oh, I guess so, yeah.
I didn't think about that. I immediately, like, whenever we were like, symbiotic relationships, plants.
Mm-hmm.
Mistletoe, parasite. Because I think parasite relationships are really interesting, and I'd already talked about the, what's the fish we just talked about? The anglerfish.
Yeah, yeah. So anyway, mistletoe.
I'm excited for this one.
Did not know that mistletoe was-
I know a little bit about it, but that's literally all I know is that it's parasitic.
Me too, other than like the traditional stuff. So a little bit of natural history, since most people don't know about mistletoe. What blew my mind was I thought mistletoe was one species.
Nope, it's a thousand different species.
Hang on, what?
Right? What? So mistletoe is not a species of plant.
It is like a term for plants.
Like-
Mistletoes. First, also, the mistletoes just sounds great. It sounds like some really funny Christmas group.
So like a caroling group. Ah, the mistletoes. So there's a thousand different species.
They live on every continent but Antarctica. And when I say mistletoe, you're thinking of the European mistletoe that people use during the Christmas season. North America has its own version.
It's the Eastern or oak mistletoe. It's got little oval green leaves and white berries.
Where is it in the Eastern US?
It's just the North American version in general. I know it's here. And remember it was in Arkansas.
That's where it first got pointed out.
Oh, that's right. That's right.
When we were driving that one time at DeGray, I was like, what's all that stuff on the trees?
And it's mistletoe.
And I was like, what? And now I see it everywhere.
Because it's like huge balls. It's not like the typical, like when you think of mistletoe, yeah, you think of a strand. And like you said, that's the European and the US the American mistletoe.
It's like a big, it almost looks like a squirrel's nest, but it's just a plant.
It's especially apparent because mistletoes are evergreen. So once the leaves fall off the trees, it means it's a mistletoe. So to be a mistletoe, like to be considered a mistletoe, the plant has to be three things.
It has to be parasitic. It has to be aerial. So it has to live off the ground in a tree, and it has to be woody.
So it's, come on.
Sorry.
There's woody plants, and then there's grassy plants.
You just paused. You just, it was just so, it was the pause.
Your look on your face. I was pausing because you're crazy weird.
I was gonna let you skate over it, and not say anything, and no.
So anyway, like I said, they're evergreen. Some have insanely gorgeous flowers. We're talking like bright red, trumpet-like flowers with yellow stamens.
They're pollinated by birds, flies, and the wind. They typically disperse their seeds. Their seeds are really sticky.
Like they're covered in this special type of sticky goo, which helps when they get pooped out by a bird. The goo sticks to a tree, and that's where they grow, where they land. So it's like that.
But there is a species that they can shoot their seeds, like really far.
Like how, wait, okay. This is, I feel like this is another measurement that we have, as far as a rat can swim, as far as a mistletoe seed can shoot.
But I don't know how many feet. I didn't write it down. There are 90 birds that are mistletoe specialists, which, again, another term that I love.
How have I missed this my whole life?
I don't know, but a mistletoe specialist, again, that's like, like should be like an elf rank for Santa's workshop. Like, you know, like. What, like that's what they call, like, that's what they call, like the, how do I say this without shaming anything?
This is what they call the really like flirtatious elves. Oh, she's a, that's, she's a mistletoe specialist.
That's amazing.
I know I want that on my t-shirt.
This is not what I was expecting at all. Large ponderosa, and this is from Washington's DNR department.
I knew it was on, it is a coniferous species.
Oh, okay, I was not expecting this. Large ponderosa of pine mistletoe plants could shoot seeds up to 50 feet.
Okay, I knew it was far.
Sometimes farther. Okay, tiny douglas fir mistletoe plants seldom shoot seeds beyond 10 feet. Large and long lodgepole mistletoe shoots seeds up to 30 to 40 feet.
Okay, that's excessively far.
So in order to go that far, you know it's got to have some force behind it. Can you imagine walking through the woods, and you get beamed with mistletoe?
It's like a Nerf dart.
Instead of Cupid's arrow, what it actually is, is you get beamed in the head by a mistletoe.
By a mistletoe seed?
And instantly fall in love with someone.
But it's stuck to the side of your head too, no less.
And it's not that you've actually fallen in love, it's that this thing has grown into your soul, parasitized you, and made you think you've fallen in love.
Anyway.
We're so far off track.
The berries are usually toxic, but those bird specialists are all about it. And mistletoe has evolved multiple times. This has worked out a lot over time for plants to just all of a sudden move up into the trees and live off of something else.
Makes sense. You're not going to have to do all the work yourself. Why bother?
So how is the relationship symbiotic? Mistletoe are what they call hemiparasites, meaning that they make some of their own food because they do have green leaves with chlorophyll, but they rely on another plant for the rest of their food. So here's what happens.
As they grow, they stab their host plant with a modified root called a hostorium. So a hostorium is pretty diverse, like the way that they look and the way that they penetrate stuff. So here's a whole bunch of penetration information.
So some of them look like a wedge, like a wedge, a pad that has a wedge under it that they put into a plant. Some stimulate the plant to grow around it, and they make these insane things called wood roses. You'll have to look it up.
It's just weird looking, and people carve them into crazy stuff. If you look up wood roses, you're going to find wooden roses. But if you look up like wood rose or hostorium or something like that.
Oh, that is cool. I mean, it looks kind of weird, but...
Yeah, it's weird. It's definitely like weird plant growth. There's something called epicortical runners, which this is cool.
So this is another type of hostorium, meaning that they go under, like they crawl along the branches, penetrating as they go. And so this allows the mistletoe to crawl out to the best patch of sunlight, but then send in, penetrate the trunk where the nutrients are.
That's smart.
Yeah, and then some actually go underneath of the bark.
Again, this goes back to our whole Hidden Life of Trees things. Like if we don't believe that plants are alive, I just...
There's certainly making decisions. Somehow, this is the best sunlight. So after they shove their hostorium in, they infiltrate the host tissue, and they actually think that they use digestive enzymes to do this, which is kind of fungi-like, really.
And so then they squirm their way through the tissues to get to the xylem, which if you guys think about a straw where all the nutrients are going up and down, usually in a tree, they tap into that, and then they suck out the nutrients from there. So the eastern oak mistletoe, which we have around here, parasitizes deciduous trees, including oaks, hence the name. But mistletoe are super diverse.
Some parasitize conifers, like pine trees. Some parasitize other mistletoe, and they've actually found them three mistletoe deep. Infiltrating a mistletoe.
It's mistletoeception going on. And then some people, so remember I said the three things that make a mistletoe are parasite, aerial, and woody. So some people consider some other things mistletoe, ones that aren't woody, but they can actually, some people do consider them mistletoe, and they can infiltrate ferns, grasses, flowers, and cacti.
Typically, they don't specialize on just one species of plant, like they're like all deciduous trees, or like they pretty much just utilize wherever they fall. And although they're bad for their host plant, they're great for wildlife and putting nutrients back into the food chain because they're constantly dropping their leaves and their berries.
Makes sense.
And so they're like sucking the stuff out of the tree and giving it back to nature, whereas the tree is going to live a long time. So like it's speeding up the process of nutrient cycling. The berries and leaves, it provides berries for food.
Leaves are eaten by a ton of stuff. Shelter and nesting material. And some species are even considered keystone species, which means like they're essential to where they are.
And the last thing I'll leave you with is that there actually is a mistletoe. There's a such thing as a mistletoe researcher, and his name is David Watson from Australia. So you too can specialize in mistletoe.
You too can specialize in mistletoe. Interesting.
And that's the hemiparasitic plant mistletoe. Well, I say plant. Plants.
Thousands of species, you know, give or take a few.
That is crazy. Okay, are you ready for mine?
Yeah.
I'm ready for mine. All right, so the first one that I have is the bird's nest fern. Oh, cool.
I don't know anything about it.
Oh, I do.
So... I do.
So, Esplenium nidius, and the only reason why I know how to say it is... I know, right? The first time ever.
Without hesitation. The only reason why is because I studied these when I was in Australia, and I had to say it all the time.
Of course, it's Australia.
Right? I know, but listen. Okay, so it's found in tons of different places.
So it's an epiphytic species of fern in the family Asplenidae, which is native to...
So I know what epiphytic is, but you better tell...
I get into it here. Yeah, I get into it a little bit. So they're native to tropical southeastern Asia, eastern Australia, which is where I study them, and Hawaii.
But they're called Ekana in Hawaiian. Which I hope so. Yeah, I hope so.
It's an E with a dash and a whoop beside it. Polynesian, Christmas Island, India, and eastern Africa. It is known by common names, the bird's nest fern.
Esplitium nidius is just like... Because again, in the plant world, a lot of plant people refer to plants by their scientific name because common names are useless. Yes, so anyway, so I'm going to keep calling it the bird's nest fern, but that's what it actually is.
Just where in Australia it probably is called that.
Yeah, so oddly enough, these plants are also kept as house plants, which makes them sound like a pet. Just keep them as house plants.
Yeah, a little house plant.
But they can grow between three, and I say that that's weird that they're kept as house plants because they can grow, and the ones that I dealt with were huge, so they can grow between three to five feet tall and two to three feet wide, and that's gonna need a crap ton of water if it's gonna be that big. But, I mean, if your house is not gonna be that big. They prefer loomy, moist, well-drained soil, and prefer partial sunlight and shade.
Fun note, they are not toxic to dogs or cats. And Kim said true, but they are god-awful to keep alive. I've never tried...
By fern, I mean, I've tried just normal ferns.
Ferns, yeah.
Too much water. They're so fragile.
Yeah, I've never tried to keep a bird's nest fern.
It's too much, I mean, remembering to water something that often.
Yeah, it's, yeah. All right, so a bird's nest fern is part of a larger group, like I said earlier, of plants called an epiphyte. Okay, I'm so excited to talk about epiphytes.
This is my favorite group of plants. I know, I remember. Besides trees.
I love how you love them. Okay, so an epiphyte grows on other plants for physical support, but they also prepare their own food, kind of like what a mussel toe is.
How weird is it that we both, I mean, man, it really is that we are on the same brain wave so often, because I start with this aerial plant. Your plant is aerial and can also grow on Christmas Island. What are the chances?
It's our brains, we just sync up. Yeah, it's just getting scary.
Across country.
So epiphytes receive more than enough light by living on the tree, surprisingly, because like most plants, they won't grow if there's not adequate light. So the epiphytes get water from the rainwater dripping down from the tree branches, and nutrients that is washed out of the leaves during the rainfall. So unlike Laura, it actually taps into the tree itself, epiphytes mostly just kind of chill and hang out there.
They're just chill. They're just hanging out. So epiphytes derive nutrients from the dead and decaying plant parts present around the surface of it.
And I'll describe a bird's nest for you in a minute. So epiphytes are a type of biological interaction known as, okay, it's symbiotic relationship, but it's pencil. Think pencil.
Commensalism.
Which is a type of symbiotic relationships. In commensalism, one of the species gets benefited, like we said earlier, and the other species is neither benefited nor harmed. So again, this is like the epiphytes are just chilling there.
I love it.
They usually don't harm their host, of course, but some epiphytes compete with their host for light and nutrients and harm them eventually. Whenever, again, when I was in Australia, there's this, it's called a strangler fig. It's not really a fig, but it ends up going up the outside of trees, and then eventually it strangles, literally, I mean, strangler fig, strangles all the light and everything from the tree and all the nutrients to where the tree then dies in the middle, and then you're just left with a hollow tunnel.
I actually climbed up a bunch of strangler figs. It was really fun, because you can climb up the middle of them. Alrighty.
So some epiphytes, like I said, compete, but birds' nests burns aren't one of the harmful types. So let's get into the ecology of it. So why are birds' nests burns in particular symbiotic?
Well, for many reasons beyond the general epiphytic reasons. One, while they don't need a tree to survive, hence the house plant life, they are typically canopy dwelling, and so they need a tree as a host. They need to hang out somewhere.
They can't just be up there by themselves. But there's actually another way cooler reason that they're symbiotic is that they also provide insects and other creatures within the canopy a place to live. And this is why I love bird's nest ferns because...
Yeah, and that's the same kind of like with the mistletoe. It provides shelter to squirrels and things like that. But yours is probably even more specialized.
Oh, it's so intro... God, this is why I get so excited. Okay, so because the bird's nest fern itself, it serves as a micro ecosystem.
So cool. Which, okay, I love...
Any little world.
It is. So I love canopy, micro ecosystem.
The concept of little worlds, though, in general, is really crazy.
I mean, if there was more money in research, in forest canopy research, that would be my focus.
Or at least a guaranteed job.
Yeah, yeah, exactly. Because I'm just spending my life in the tree canopy.
That just reminded me. I remember you're insane. Like, not insane.
It was a good idea. But remember, another one of your business ventures.
Yes, it's always the canopy park. I always have business ideas, always. One which is actually coming to fruition, finally.
But yeah, one of my crazier ones was that canopy animal park, which still, if anybody wants... Yeah, Laura was going to be manager of operations. It was going to be amazing.
But canopy stuff, it just makes my... It's so interesting. Okay, so what is a micro ecosystem that gets my motor running so much?
Well, a micro ecosystem is a small scale ecosystem. It's a subset of the surrounding biotic community and environmental factors of the larger ecosystem. So it's basically a tiny picture of its larger surrounding.
They show all the common features of an ecosystem, such as production, decomposition, energy flow, nutrient cycling, everything.
I think it's why people love like terrariums so much.
I think so too, yeah. So not only are bird's nest ferns microecosystems, which is cool in itself, but they take it to the next level because they also form their own microclimates. Yes, so these ferns are basically like self-sustaining mini-snapshots of all of their surroundings.
So how they do the microclimates... So if you picture a bird's nest fern, if you Google it, you'll see tons of pictures of it. There's the base, the bottom, with all the soil, the roots, and everything in it.
And unlike the mistletoe, this one, the roots just kind of hug, and it goes around the tree branch, and then up from it, it's like the prongs of the... Is that what it's called? Prongs of the fern?
Fronds?
Fronds, fronds, font-fronds. Yeah, it's definitely fronds. And it goes up, and then it's like around, so they all stick up.
And so because they stick up like this, it's almost like it protects everything in the middle. And so it keeps it humid in there, which sometimes up in the tree forest canopy, like all the humidity is down on the forest floor, not that high within the canopy, and so it keeps that moisture in there. And so it really does sustain its own microclimate, which is so cool.
And so there are species within these microecosystems within bird's nest ferns that you can't find anywhere else but in bird's nest ferns, which is amazing.
Specialists are so interesting that way.
So interesting. And because it's a self-sustaining system of life, death, and decomposition, you basically have everything you need there to survive if you were an insect. And I also picture this as like, there's a species that lives there, their entire life's in an epiphyte, and they have zero clue what's on the outside, bigger world that exists, but one day they have an existential crisis and start questioning life's meaning, and then find out there's life outside the fern.
So Disney can contact me if you would like to discuss further plot development.
Yeah, it's like The Who, like on the clover.
Oh, this is way better.
Well, yeah, I'm just saying, like, relatable.
No, it is. It totally is. So what's also amazing about the birth of this fern is it provides habitat to a variety of species, like I said, some that can only be found in epiphytes.
So what can be found there? Ants, lots and lots of ants. One of the worst ones that I dealt with in Australia were the jumperjack ants, that they actually jump, like they fling themselves up at you.
They have, so ants, they'll have their colony in the base of the plant where their dirt and decomposition is, because they're ants. And then in return, so another symbiotic relationship, not just because of the epiphyte, the birth of this fern and the tree itself, but the ants then, they get a home from the epiphyte, and then in return, they actually protect the leaves from other invertebrates from eating them.
So that one's mutualistic.
Yeah, so it's, again, another symbiotic relationship. So I also found a really cool article about frogs within epiphytes.
I've heard of this with epiphytes in general.
Yes, so, which I do think our tagline for our podcast should be, we read research abstracts so you don't have to, because I feel like that's what it's turning into.
Absolutely.
But there is a study done by Brett Shephers and Brett Shephers, Ben Phillips, and Luke Shue, in which it showed that ferns are the preferred diurnal microhabitat and breeding habitat for our several species of arboreal frogs.
I love that image. So instead of a bug, it could be like this. I just love that this frog has this own little world that they can live and thrive in and just forget about the outside and the dangers of the rainforest.
Just happy little place in my fern.
Between one fern? We could start our own show.
Between one fern. So they did show in this research that there's a strong positive relationship that exists between fern size and frog usage and abundance, which makes sense. So the experiment showed that the large ferns buffered the maximum temperatures and reduced variability in temperatures, and buffering is directly linked to their hydration.
So again, big leaves forming a microclimate. It's more reliable than what is the commonly unpredictable climate of the rainforest. But in their research, they showed that frogs are likely using large ferns for their moist, cool environments for breeding and daytime retreat, which supports the buffered microhypothesis.
I'm pretty sure I read somewhere once, too, that a lot of arboreal tree frogs will lay their eggs in epiphytes because there's water in there.
Oh yeah, again, it's like the perfect living mini-ecosystem. And if you've listened to any of our other episodes about frogs, they're an indicator species. An indicator species tells you how healthy or unhealthy an ecosystem is, because they are insanely picky about their habitat and where they breed, so if frogs are living in an epiphyte, it must be a hell of a place to be.
Which goes into the conservation of epiphytes and why they're important for the ecosystem, because researchers really can look at an epiphyte and study a micro-ecosystem. It's like taking a snapshot of the surrounding rainforest, look at it, study it, and just see, again, a snapshot of what's going on in that rainforest, because you figure the rain that's falling off of the trees, so that tells you what nutrients are picking up there, if it's just water, what's going on. The decomposition around it, you know, it's falling into it, so it just tells you so much about them.
So epiphytes and bird's-eye spurns are extremely important and heavily studied.
Does it matter from a lot of species that are in the area?
It gives you that perfect little snapshot. So in conclusion, bird's-nest ferns are by far my favorite symbiotic relationship because they are the definition of it tenfold because it's like symbiotic relationship on relationship on relationship. Okay, I got to calm myself down.
That's epiphytic bird's-nest fern. It's so good.
It is so cool.
It is so cool.
I love many worlds.
Yes.
Here we go again. The perfect segue.
It is. And yours? To mine.
Of course it is.
But this is going to be a way to calm you down because this one, even though it is a mutualistic, commensalistic relationship, I had an existential crisis after researching this one. So my mini world that I'm going to focus on is your skin flora.
Shut the front door. You have, okay, listen, listen.
Wait, were you really thinking about doing this?
No, I'm saying.
Or just the fact of the small world.
No, okay, it is the small world, but I'm saying like you already have OCD, and medical stuff is what frees you out. And so what do you research? Your skin and what's there?
It was really interesting.
It was really interesting.
You know what? You're setting yourself up for a crisis here.
But so I'm taking a small roll even further to the microbes that live on your skin. Fascinating. So and gross, but cool.
So humans have an invisible relationships with lots of different things in and through our bodies and on them. And some of them are animals, but we're not talking about that today. Instead, I'm just lumping everything together.
So it's the bacteria, the fungi, the viruses, and the little micro animals that live on your skin. It's also known as skin flora, also known as the skin microbiome. That sounds a little better.
Yes, skin microbiome. Let's just call it that.
So the majority by far, there's a ton of research done on this.
I believe it, because you can be your own test subject.
I read a lot of abstracts, and they've... Well, I'll get there. What they found in many studies is that by far, the majority of what is living on your skin is bacteria, surprising probably no one.
And the least thing living on your skin is fungi.
Okay, I mean, that's probably a good thing.
Yeah. Oh, yeah. Some come and go, and some are permanent residents.
So I seriously learned so much. Of course, I knew that we have stuff living on our skin. But how it's all working together is fascinating.
So the way you even get your skin microbiome is during birth. When you're inside, you're completely sterile.
Yeah.
Duh. So for babies born vaginally, that is the dominant micro-like skin biome at the time. And for babies born for C-sections, their skin microbiome is mostly like skin-related bacteria that's like from their mom's skin.
Yeah, it makes sense.
Yeah, because you're coming out through skin, so your microbiome is determined by a lot of different things. Your skin is acidic, which I didn't know, so it's got a pH of 5 for anybody who knows their scale. So it's got an acidic pH.
For all those wondering.
So it's determined by your skin's pH, determined by the moisture level. I was going to say you better put it on your drink. I try to keep taking soup.
The moisture of your skin, the temperature of your skin, the oxygen carbon dioxide ratio, sun exposure, interactions with other microorganisms, innate host defenses, and your genetic makeup. However, with all of those factors, your microbiome stays pretty stable over time. The only complete restructuring of it is during puberty, which makes sense because your hormones change, so your skin changes.
And that's why actually you see your skin is the best indicator of your age. What grows on your skin? Kids, there are different micro-bots, red groups.
He said, what grows on your skin? Okay, you said, what grows on your skin?
It feels like it sometimes.
It goes back to the whole baby, sucked to your nipple thing.
Yeah, yeah. So kids have different micro-biomes than adults. So what do humans bring to the table of this relationship?
So like I said, the relationship that you have with what lives on your skin, for the most part, is either mutualistic or commensalistic. So either win-win or at least a win and nothing. So what humans bring is that our skin provides...
I can't even believe this number. You know how like you hear these crazy numbers of like how many feet of intestines are in your body?
Yeah.
You know, stuff like that. I read two very different numbers, and I'm assuming that this number must be because of all the nooks and the crannies, and they probably are including like...
I mean, some people have more nooks and crannies than others.
Oh yeah, but not by... So one measurement, the average human, some places say has about one and a half to two meters square of skin. Totally makes sense.
But so gross.
But I'm assuming that this other number that I got from a scientific article is including like... So a lot of these bacteria live in the follicles. So if you took all the nooks and crannies of your skin, you have about 30 meters square of living space on your body.
I don't know if I believe that one.
I don't know, I don't know. More research possibly. But anyway, if that's true...
I mean, like you said, I guess if you took all the follicles and flattened them all out and stuff like that, I mean, I guess that would make sense.
Maybe, maybe. So regardless, it's a lot of living space. So we provide the home.
We also provide... Oh, and these homes are extremely... So the environment that these microbes live on reflects what lives there.
So this is where it gets gross, but kind of interesting. Lots of studies done where they tested all different parts of people's bodies, and they categorize them into three categories, and where the environment there directly impacts what bacteria live there. So there are the dry parts of your body, such as your hands and your legs.
There are the moist parts of your body, such as the creases and in between your toes. And then there are the sebaceous, or the oily parts of your body, your head, your neck, and a couple of other places. So those are the different environments.
So just like, you know, your skin is an ecosystem, and just like ecosystems have different habitats, so does your body. And so we also provide the nutrients for this stuff. So they're eating our fats and our proteins and our oils.
Yeah, gross, but necessary, I suppose.
I suppose.
But the comp—like, there actually isn't a lot of stuff for them to eat on us, so their competition is fierce. So that's what humans provide.
Fight club!
Yeah, a little back to the fight club. What do the microbes bring to the table? This is where it gets interesting, and I didn't know any of this.
Basically, it all boils down to that they keep our skin healthy. But how exactly do they do that? Well, some are just hitchhikers that take up space so there isn't enough room for other things to grow there, like the bad stuff.
So this is commensalistic. They just live there, using up resources so that pathogens, which are bad, like bacteria and viruses and stuff, don't have room to grow. So they're just taking up too much space.
But some of them actively keep our skin healthy. So this is where mutualism comes in. So when you're born, right away, microbes go into your hair follicles.
That's so gross. So they go in there, and then they start having this... They're talking, basically, to your skin cells down there, and they're educating them.
So great image of these little bacteria in your skin cells.
I know you're new here to the world, but let me tell you how it's going to be.
It really is like that. And they're like, how it's going to be is that some of us are okay, and some of things are bad. And the bad things you keep out and the good things, like me, you let us stick around.
That is such a creeper statement, though. Like, how do you really know what bacteria to trust?
I don't know.
Because one of the bad bacteria gets in there first. Does a bad bacteria win and convince?
Maybe they don't bother educating and just try and take over. I don't know. But basically, these microbes educate the skin cells, and that is how the skin cells learn their immune response.
Interesting.
If this doesn't happen right away, you have no immunity on your skin. Crazy things can happen. They were testing with mice.
So they teach your skin to tolerate the majority of what it comes into contact with. Otherwise, you'd always be sick.
Yeah, exactly.
They can also modulate the inflammatory response of the skin. They help in wound healing, which was another, like tons of studies have been done, analyzing what actually is in wounds and do microbes help, like what's living in there and how does it help? So it can help heal.
And then also some of them actually, like through their process of, you know, eating and, I don't know, it's not living. They're like producing and digesting and things like that. They are creating antimicrobial molecules called bacteriocins.
So they're actually like actively secreting antimicrobial stuff onto your skin, protecting you from other bad stuff.
That's what I've always wanted is secretions on my body.
Hey man, I'll take antibacterial secretions on my skin any day. Bring it on!
Fight club and secretions.
So they do, I mean, without them, we wouldn't be able to live in the world.
We would always be sick.
Always be sick. And interestingly enough, as we age, our microbe diversity lessens, and this is thought to contribute to skin aging, and makes you more prone to infection. Interesting.
The whole thing is all kind of tied together between, is it that the skin is affecting the microbes, or is it the microbes that's affecting the skin? It's kind of hard to tell, but like I was saying, it's like...
You would think that since old people are so wrinkly, there would be more space to live.
But I think that their hormone, like the actual, like what their skin is made of... Maybe there's even less nutrients for them.
Yeah, that's so gross.
And so as awesome as this relationship is, as absolutely necessary as this is, it is insanely finely balanced. So some helper microbes can quickly turn into pathogens under certain conditions. And we're talking like hairline balance.
So you've got strep bacteria all over your body. Let's say you get a cut. That strep is forced into your wound.
That can make it turn bad. It needs to live in a certain... Like they're very picky about how and where they live and the conditions that they live.
If you become immunocompromised, then your body can't handle even the little bit that's on your skin.
But that's what they say about cancer cells, though, is that everybody has the possibility of cancer cells in them. It's just under the right conditions. They can be activated at some time.
And you know what I mean? And it just goes.
Yeah, so it is all so... But that's the amazing part of nature that we're always talking about. It's how fine-tuned nature is in general, and we're no exception.
Everything about our bodies is perfectly balanced, and when the balance is disrupted, that's when bad things happen. Sometimes that's completely normal reasons, like you just get a cut, or you age. And then other times, it's just where I was having my existential crisis.
So of course, this leads to... Well...
Here we go.
If I'm... I'm clearly using too much hand sanitizer.
Oh, yeah.
Hand sanitizer is killing every microbe on your skin.
So my dad, before he passed away, he was an avid nail biter for his whole entire childhood. Avid nail biter. And so he finally stopped because he started using hand sanitizer, stopped biting his nails, and then that's whenever he started always getting sick.
And he always was like, it's because I stopped biting my nails off. And he was like, as gross as that is, he's like, no.
I would be eating a lot of bacteria.
I'd be eating a lot of bacteria, and now it's as a hand sanitizer, so it's getting rid of the micro, you know, the ecosystem with on your skin. Stop, you know, tiny doses of bacteria under your fingernails, which is so disgusting to think about. But then he started getting sick, and he swore by it till the day he died that he was really getting sick.
I mean, I definitely, it's definitely, I was reading some articles about it, and of course, we live in a day and age where we know that there are, I mean, hand sanitizer, washing your hands, it's all important. I mean, if, especially like, there was an entire article written on like the, you know, the pandemic. What are we supposed to do?
What's worse? It's essentially weighing, it is trying to keep the balance as best you can.
It's the same thing in your gut, though. I mean, like, whenever after you have like certain medications, they say you need to have a probiotic, because you have to re-regulate the fauna in your gut, because you've wiped it clean.
Because actually, gut are maybe even more important than this thing. I actually was going to talk about gut fauna, but then decided to do skin instead. So, you wash your hands.
That doesn't wash off everything. It's pretty great at getting rid of viruses. So like washing your hands is the preferable.
The hand sanitizer just kills everything on your skin. All the little bitty guys, all the bacteria, all the viruses. And so then you've just got a clean slate on your hand.
You're just disrupting the balance. Can you disrupt the balance every once in a while? Absolutely, and you should.
Like you should absolutely wash your hands before you eat. You can't try and use some hand sanitizer. But do not over sanitize.
Not only should you not use too much hand sanitizer, and I already knew that. I mean, I knew it's not good for your hands. But what I didn't know about was that there are certain products that contain a certain type of antimicrobial dial and other products that can contain antimicrobial chemicals.
When you put them on your hands, it not only kills what's on your skin, but it can actually be absorbed by your skin. Go into your bloodstream and kill the bacteria that are living in your gut, your gut flora, which are insanely important. And if they die off, can cause huge health issues.
Interesting. It affects behavior?
And a lot of companies have moved away from using this because it's just too powerful.
And, of course, with all of the bacteria-resistant everything that we're creating because of all the sanitization that we do do, so coming from someone who needs to be sanitary, it's just like... Believe me, guys, listeners out there, anyone who struggles like I do, having a baby is breaking me slowly.
Because they're so gross.
And having to be a better person because you have to let things go because you can't sanitize them all the time. Like, I have to just...
And they're gross.
And I know she's going to lick the floor and things like that, and I'm just going to have to get over it.
One time we were in an airport with Luke, and we turned around, and he was just licking an airport window. And I was like, that's... I thought that was the worst, and then I was like, don't lick the window.
He was itty bitty. I was like, don't lick the window. And I turned around to say something, and I turned around, and then he was licking the airport floor.
And you can only... Yeah. I had a straight up panic attack, and then be okay.
I saw a friend's kid drop pasta on the sidewalk, and then eat it from the sidewalk. And I was like... I was like, oh my gosh, but people walk on the sidewalk after they've walked through dead animals.
My brain goes like, I can see the trace back. And it's a living nightmare.
But I will say, I will say that with the gut stuff though, a lot of people knock it, as far as the importance of gut health and how much it affects you, because so many holistic healers focus on your gut health that it's kind of knocked. But no, it's a legit thing. Like you said, it controls so much of your healthy immune system.
And to an extent, again, anything in moderation can be good. And so like the detoxing and stuff like that, within moderation, it can be good. Do you do it all the time?
No, I know some people that do a detox, and they eat regular food and everything for a week, and then they do another detox. No, you're killing your internal system. That is why you don't feel good, because you're going overboard.
But taking care of a good gut health is so important for your overall well-being, your mental health, just how good you feel. Your gut health is so freaking important for that.
Yeah, and so your skin microbiome is essential to keep you healthy as well. So again, everything in moderation. Am I gonna wash my hands a ton still?
Yeah, because it's better than hand sanitizer. But I can consciously recognize the fact, and I do all the time with baby. With baby.
Exposure to some bacteria is good. It is a good thing. It protects you in the long run.
But yeah, so that's our, I mean, we don't even know that these relationships exist because they're happening on such a small scale.
Yeah.
But thank goodness they are. What's our last relationship? Oh wait, I know.
Yeah, you already know.
I think I know this one.
No, you know this one.
Sometimes because we send our ideas to Kim, if we overlap, she has to tell us that we overlap.
Yeah, so she already told me that you had said you were going to do this one, but you knew I would do it.
I love it so much.
My second one doesn't get me as excited as a bird's nest fern, but I do like this one because growing up in Western PA, these are everywhere. And since they could be seen everywhere, I took a liking to them.
Hey!
And it's lichen. L-I-C-H-E-N.
And lichen are everywhere.
Everywhere. So there are approximately 3600 species of lichen in just North America.
I was just going to say that can't be world.
No, just in North America. And that's just the ones we know about. There's so many more that we don't even know about.
It's got to be like the fungi with the dark taxa.
No, there has to be. Well, because every year, literally every year, there's new discoveries of lichen being made.
Wow, I want to find some.
We just need to get better at identifying lichen and we can find our own. All right, lichens are found all across North America, literally all over the world, like we said. They are among the hardiest and most resistant of all plant organisms.
These primitive plants can withstand long periods of drought, intense heat, and freezing temperatures, making it possible for them to live where nothing else can. These plants have no stems, no roots, and no leaves. And I know you've seen them on rocks.
I don't want to say the stereotypical like it, but the one that you're often going to see is almost fuzzy in appearance, and they're like sandwich flat against the rock. And they're on trees. I don't know how else to describe it.
I think they kind of look like flattened flowers. They are very kind of like petaly looking almost.
You've definitely seen them. If not, look it up. L-I-C-H-E-N.
But there's tons more colors in a variety, but that is like the stereotype lichen. So these fuzzy green looking ones are only one of the 3,600 different species found in North America. So what is a lichen?
Like you said, symbiotic relationships here. So lichen are actually a combination of at least two different organisms. And we'll get to the at least part in a bit because that is important.
So part one is there has to be an alga, a plant, or cyanobacteria. And part two has to be a fungus. So the composite body, the alga-fungi combo of the lichen, is called the thallus.
So the body is anchored to the substrate by hair-like growths called rhizines. The thallus is what you are typically looking at when you see a lichen, like just that big body. So of these, there's different body types, too.
Some are spiky-looking, flat.
Yeah, crustos, fruticose, and follulose, which I'm like, geez, could you just differentiate those names a little bit? And I'm not going to go into the detail here because I want to talk more about the symbiotic relationships rather than lichen bodies. So, symbiosis.
We already know it's made up of at least two things, so that right there is a dead giveaway that it's a symbiotic relationship, or else we wouldn't have made it this long, evolutionary speaking. So the relationship, though, the algae or cyanobacteria manufactures the food for the partnership, while the fungus, which has no chlorophyll and cannot manufacture its own food, traps the moisture and anchors to the plant the rock tree or whatever it is.
The structure and the food maker.
Yep, pretty much. So this symbiotic relationship between algae and fungi is complex, but an interesting one at that. So earlier, I mentioned that lichens consist of at least two different organisms.
So lichens were once, way back in the day, classified as a single organism. That wasn't... It does, because I would never guess it.
How would you ever know that?
Yeah, there's no way. Well, and that's whenever they started. That's whenever they were like, oh, this isn't actually one thing, this is two.
And it came with the invention of a microscope. And that was whenever the association of a fungi with the algae or cyanobacteria became evident. Again, I get it, because if you just look at it, you would never...
To the naked eye, you would never know. Well, in more recent years, scientists have found yet another fungus within that plant. So it's not two anymore.
And it's called Bacidio mycete yeast, and it may be the third symbiotic partner in many, many, many lichens.
So it's a specific kind of fungi.
Yes.
Yeah, the Bacidio... Yeah, yeah, yeah. I remember when we talked about our fantastic fungi, that was one of the groups.
Mm-hmm. So first, at first, humans in general thought that lichens was one organism. Then we thought it was two.
But now scientists see lichen as a community organism, which is so cool.
Yeah, that sounds cooler.
Way cooler. Yes. So in the research that's being conducted right now, instead of studying only one fungus and one alga, they looked for genetic differences, and all fungi, between two different lichen species.
And that's when they started to find that the yellow lichen with valpinic acid had a much higher number of genes belonging to that yeast. Researchers then started to expand their scope, looking at more, and they started to screen other species of lichen and found that different species carried genetically distinct that basidium mycid yeast. When they took one species in Montana specifically and compared it with the same species in Europe, they found that the basidium mycid yeast also stayed the same.
Suggesting that the species of yeast was highly specific to the species of lichen, rather than just being a product of the lichen's environment or whatever is around it.
But that's so interesting of what came first. So is it the yeast that determines the type of lichen or is it the lichen that determines which yeast can live there?
Or is it a combination of both? Because if it's a community, because in our minds we thought two and then now we have this third one, but they're saying now if it's a community, then you have to have all three of those together for it to actually make a lichen.
Yeah, I would assume that it's got to be that the yeast is determining type, because it's coming in at the same time as everything else. Like the yeast and the other things, the combination determines the type.
Yes, but again, we're discovering new things about this every single year. So the next task after this was for the researchers is understanding whether the basidiomycete yeast play a role in building the lichen structure. Because if we know what the fungi does, if we know what the algae or cyanobacteria does, what does this yeast actually do?
So the functions of these yeasts might bring scientists closer, and they don't really know at this point, but they think that by understanding this and studying this more, they might be able to synthesize lichens in a lab, which is a feat that would allow researchers to study in lichens without having to collect them in the wild. Can lichens be reproduced in a lab? Yes.
Is it difficult? Absolutely yes. Just because, again, like Laura was saying, that fine hair, that fine line of being able to create something, whatever it has balance or it doesn't have balance, it's very difficult to recreate that.
So what do lichens do? Just an overview. So what do lichens do, and why would they want to even grow them in a lab?
So most rock-growing lichens play an important role in ecosystems by converting rocks into soil. Lichens produce a weak acid, which slowly dissolves the minerals, forming tiny cracks in the surface of the rock.
I always like to tell kids, like when we see lichen, I'm like, they're eating the rock.
They're eating the rock.
Like, they're just super cool.
Yeah, and it's important. Yeah, we need soil. Yes.
So during the cold weather, the moisture in these cracks freezes, often breaking or splitting off pieces of rock, and it just keeps going over. Little progress is noticeable even after a century, so it's not like this is like a fast process. But again, whenever you're on geology's time, like you think trees are slow, geology time frame is even slower.
So to lichens...
How long do lichen live?
Well, I mean, if they're over a century old on these rocks, and it's not even seeing a breakdown. But yeah, so I mean, they do play an important role, and it's the same thing with like on trees and stuff. They break it down.
So they're not classified as a decomposer, but I mean, in a way...
I think that they should be.
If they're not... Let me Google this.
Yeah, because I guess a decomposer probably is organic material.
Yes.
That's gotta be definition. And lichen are inorganic material.
Okay, so one quick thing says that lichens are considered decomposers, fulfilling an essential role in the ecosystem by breaking down dead, sometimes living things.
Dude, Katy, I just looked up how long do lichen live. And...
It's gotta be a long time, like sea turtle life.
There are lichens in Antarctica that are estimated to be approximately 500 to 5,000 years old.
That's insane. That's insane. I like it.
An average of some are 100.
That's just craziness. Uncalled for a lifespan.
I mean, cool.
So that is an overview, because I don't want us to go too much longer, but that's an overview of lichen. Another really cool thing... Oh my gosh, I could.
Radiation sponges.
I had to keep it so short. The listeners, if you guys want us to do a whole lichen episode...
If you're lichen that lichen.
We could totally do a lichen, because oh my gosh, it's so much deeper than just what I went into. But another cool fact that I found. So if you grew up in a Christian home, or went to church or whatever, there's this story about manna from heaven.
What?
Yes.
You're saying that's lichen?
Yep, because lichen in that part of the world will actually sloth off and go through the wind. And you can eat a lot of lichen. It's completely edible.
And so a lot of researchers and historians think, okay, if manna from heaven is coming, it was that correct time of year that lichen would be falling off the trees and blowing through the wind and was lichen manna.
My brain just exploded. That's incredible. I hope that's a real story.
Right? They were just munching on fungi.
I mean, so cool.
I mean, people eat lichen all the time.
All right doesn't mean that manna can't be lichen. It doesn't have any bearing on the validity of that story.
No, I would love to do a whole lichen episode. I really, really would, because it is so interesting. And I had to hold back so much more information because I want to keep us with that time frame because we're already over the hour hit.
All right, well, we better wrap it up for the sake of it. Symbiotic relationships are really amazing, and they do play an important role. So I hope you guys learned at least a little something today.
At least, if anything, just my love for bird's nest ferns.
I was going to say, hopefully, that you could see that some symbiotic relationships are beneficial to some and not beneficial to others. It depends on the species.
I mean, there are some things that just get, I don't know, get you deep down excited. And tree canopies and bird's nest ferns does it for me. Just every time.
I get so excited. I don't know why. It's just something in my core that I'm like, this is amazing.
I feel a lot like that about fungi. It's so cool. It's something about it.
So anyway, so hopefully maybe you feel a little bit about, a little bit more, I guess. Not quite as much as I like bird's nest ferns, but hopefully you found something amazing in this episode. Be sure to follow us on social media and check out our Patreon page, and we will talk to you guys next time.
Tune in next week!