Wildly Curious

Living Things: Diving into the World of Protists

Katy Reiss & Laura Fawks Lapole Season 5 Episode 2

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In this episode of Wildly Curious (formerly For the Love of Nature), co-hosts Katy Reiss and Laura Fawks Lapole take a quick but fascinating dive into the world of protists. These organisms, often overlooked, play a vital role in ecosystems and life on Earth. From protozoans to algae, slime molds to amoebas, this episode explores how these unique single-celled creatures contribute to everything from oxygen production to decomposition. Whether you're a science enthusiast or just curious about the tiny yet essential building blocks of life, this episode is packed with insights you won't want to miss.

Perfect for listeners who love exploring the basics of biology, taxonomy, and the mysteries of the natural world. Learn how these seemingly simple organisms are key to sustaining life on Earth.



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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 Katie. And today we are gonna do another, I would say deep dive, but this one's gonna be really short.

A superficial dive.

Yeah, superficial.

To do another taxon. Yeah.

Superficial dive. And we are gonna be talking about protists.

Yes, so we were gonna talk about how protists are essential to life on earth. So as a quick refresher for everybody, we said that we wanted to kind of make our way through different taxons of animals and plants. Well, taxons of living things.

So all life can be categorized into eight levels, each getting more and more specific. We previously covered bacteria, which is a domain, and that's the highest level of life, and fungi, which is a kingdom, aka the second highest level. So taxonomy is complicated and constantly changing.

So, you know, things are always, people are discovering things, they're lumping things together, they're splitting them apart, but we're kind of making our way from the top down.

Yeah.

So today we're talking about protista, which is a catch-all group. So protists, which are either a kingdom level grouping called protista, which is under the domain, eukaryote, which those are living things that have cells with a nucleus, or people sometimes consider them several kingdoms of stuff, depending on the scientists you ask, because protista is a catch-all group for any eukaryote that isn't a plant, animal, or fungi. Like that's the definition.

Which is a catch-all group. Thank you for the definition.

Yeah, literally just anything else. So they're all pretty different than one another, and there's no rule for what they all have in common. Most are single-celled.

Even if they are multi-celled, they aren't multi-tissued. So that means, like...

It's one thing.

One thing. One thing. They don't have, like, organs and things like that.

Some are more like plants, while others are more like animals. Not all are microscopic. Some are.

Some are mobile, others aren't. And some scientists agree that this shouldn't be a kingdom at all. Definitely it should not be.

Yeah, I don't think it should be.

Because they're nothing alike.

Nope.

It's like, this is the-

It's a catch-all.

Shubbed under your bed.

Yes, it is. It is a catch-all.

I don't know what they are, so we'll just say this. But because of genetics and stuff, we're learning more and more about these guys. And so really, I think we're getting to the point where we could come up with some more kingdoms.

I think we could. I think we could.

So there are anywhere from 60,000 to 200,000 species lumped in this category.

Whoo, that's a lot.

Yeah, and they can be broken into three groups. There's the protozoans, which are the animal-like ones. Those are things like amoebas, ciliates, flagellates, a couple of other things.

Then there's the protophytes, which are the plant-like ones. That's things like algae, diatoms, and a few others. And then there's the fungi-like ones, which are slime molds and water molds.

So at least there should be three different kingdoms in here, the protozoans, the protophytes, and the fungi-like ones. So as I said, they're all super different. So I'm just going to talk about some characteristics that some of them may have that stood out to me.

So the ones that are photosynthetic create their own nutrients from the sun like plants do, though the equipment that they do this with may be a little bit different than plant cells.

Yes.

Ones that are heterotrophic, which means ones that need to eat other things, like how animals need to eat, they can be broken down into two groups. So like when we think about eating other things, we're thinking like we eat plants, we eat meat. Well, these guys have different ways of feeding because we're talking about single-celled organisms here.

So there are ones that we call phagotrophs, meaning that they surround and swallow things, like an amoeba. They'll like surround the whole thing and then just something. Yeah.

Then there's the osmotrophs, and they're the ones that just absorb stuff from their surroundings.

Because why not?

The lazy ones.

Yeah.

Yeah, yeah. They don't hunt, they don't, they literally just absorb what's around them. And then there are some, I thought this was cool, there are some that are both photosynthetic and heterotrophic, and so they are called mixotrophs.

Original, I know.

Right?

Mixotrophs.

Good job, scientists. Being lazy.

Some produce asexually, which means that they just split, like through like binary fission or some other ways, and others are sexual, and some could even do both. Many can move around using either cilia, which kind of look like undulating hairs, or flagella, which look like little tails and makes them kind of look like tadpoles, although they can have multiple of them. Or they can move around using pseudopods, which I love that word, and that means like squishy feet, essentially, and that's the things that amoebas have.

So they kind of like stretch out a foot, pull themself along, stretch out a foot, pull themself along.

Which is weird, but then cute at the same time.

Yeah, yeah, I think amoebas are kind of cute. So that is the different types that there are, ish, and the different characteristics.

And when you say ish, we really mean ish, because that's why this is, it really is a catch-all group. And I remember learning about these in college, but I don't think I realized how haphazardly these ones were thrown together.

And I think that is because we're realizing more and more like they're not at all alike.

Yeah. And right, are they a domain? Are they a kingdom?

I think, like you said before, I think that scientists-

One kingdom or several, I should say.

And I think we're far enough along of learning and knowing about them, that one, we should be able to put these either in different groups, if we figure out, okay, we know a little bit more about them, we can put them over here or over here, and kind of divide this group up a little bit more, because it is just a really bizarre group.

Yeah, well, because some of them are more related to a plant than they are to each other.

100%, yeah.

If they're not in the same group, if they're not even related.

Yeah, not at all.

And if you look up some trees of life, or some taxon charts, they have broken them down-

They have.

Some have broken them down into several kingdoms, but this is not a consensus across the board. You can still find kingdom Protista, and then other people are like, Protista does not exist. So it kind of depends on who you ask.

But I think basically, basically single-celled organisms that aren't plant's fungi or animals, but are like all of them. A lot of scientists think that this might be, this might be the first eukaryotic cells.

Yes, the first.

Probably this is where animal plant fungi life came from, ish.

Which would make sense, but at the same time, divide them up a little bit.

A little bit simpler to more and more complicated. So, Katie, what purpose do they serve? Why do we, should we even care about them either?

Holy crap, that, you only have seven minutes. You're only seven minutes at.

Hey man, it's a sure one.

It is gonna be a very sure one. All right.

We said a superficial dive.

It is very superficial because I think it's, one, even though they are very diverse, there's really not a whole lot to talk about them.

Without going real.

Really deep.

But because they're so different, I feel like it'd be hard to go really.

It would be because, because it's so drastically different. They would be so drastically different.

We gotta break it down into multiple episodes, I.

We would have to.

I think, maybe at some point. Like, cause I think protozoans are really cool. I'd like to know and talk more about them.

And like, maybe not like water molds and slime molds, but protozoans.

Yeah, would be cool. It's just these ones aren't. All right, so what is.

We're just talking about the highest level of it.

Yes, all right. So what is the purpose and function of these guys? If they are so diverse.

Again, they kind of are a catch-all. So their purpose and function is a catch-all.

Catch-all.

So one of their jobs functions is they are primary producers slash food sources for a lot of things. So once I start talking about this a little bit, you'll be like, oh, I see where these kind of fit in. So they are a central food source and provide nutrition for many other organisms.

In some cases, example, zooplankton, which are protists, they're consumed directly by a number of sea animals. There are even photosynthetic protists that serve as producers of nutrition for other organisms. Paramecium bursaride, I don't know.

And several other species of ciliates are mixotrophic, like Laura was saying, due to their symbiotic relationship with green algae. This is a temporary version of the secondary endosymbiotic chloroplasts found in Euclena, whatever Euclena is.

Oh, the Euclena is some organelle in a cell.

I thought you were just gonna say, oh, the Euclena. I was like, oh, what do you have against the Euclena? Yeah.

No, I was just making me think, though, that you were talking about the zooplankton, the phytoplankton. I feel like there's a magic school bus that I always think about whenever I think about zooplankton and phytoplankton, because I think they become them to learn about the food chain, maybe, or something. I don't know.

But talking about how some of them, like zooplankton, are microscopic, but not all of them are. For example, that brown algae can be like 137 feet long, and that is considered a protist. Really?

So you go from like, Oh, true, I guess so, yeah. To like, whoosh, which is so disgusting.

Yeah.

Eww, anyway.

But things eat the algae, and so again, bottom of the food chain, whether it be the plants or the animals.

Yep, and plant-like or plant-like. Yes, and so there's another one called Zuzanolil, Zuzanolil.

So they provide nutrients for coral polyps, which I mean, we all need coral polyps.

We all need coral polyps, well, the, I mean, the ocean. It was a known fact. Oh, we all need coral polyps.

I've never used a coral polyp in my life.

The oceans do, the oceans do. But that actually gives the corals a boost of energy, which helped them to grow, of course. And so again, food, because they are so small.

Oh, let's see here.

I love looking at things under a microscope.

Like it is really fun.

Like the bacteria and stuff are like, eh, kind of cool, but they don't move. But like, when you look at things and you can see things moving around.

Yes, way cooler things.

Super cool.

So with those coral polyps, though, for these proteases.

The corals in turn provide the protease with a protected environment and the compounds needed for photosynthesis. So it is like kind of a mutual symbiotic relationship. So it works out for both of them.

They eat and then also find a home there. Yes, here it is. So the other thing, unfortunately, human pathogens.

Lovely, right?

A human pathogen. So even though it's not a good function and it's not a good purpose, this is still what they do. So anything, I feel like everything we talk about ends up leading back to something as it ends up being a disease.

So many things are like, oh, that can kill you. Well, that's nature, man. It really is.

All right, so let me give you some examples here. So one of the protists is Plasmodium, which is-

I was just gonna say malaria.

Malaria.

Like, the most famous.

So in 2015, the WHO reported over 200 million cases of malaria, mostly in Africa, South America, and Southern Asia, however, it's not well known that malaria was also prevalent, also prevalent disease in North Central region of the United States, particularly Michigan, with its thousands of lakes and numerous swamps. Yeah, which makes sense, which I didn't know. All right, so prior to the Civil War, and the drainage of many of those swamps, virtually everyone who immigrated to Michigan picked up malaria.

Whoa!

Yeah. Didn't know.

Didn't know.

Let's see here. And it says, and the pale, shallow, bloated faces of that period were the rule.

Lovely.

Right?

The malaria face.

The only healthy faces were worn by those immigrants who had just arrived, which is insane, that it's like that commonplace. You're like, oh, you're an out-of-towner because you've not looked diseased.

Like, yeah, you look healthy.

You look healthy. You must not be from out of town. Yeah, you must not be from out of town.

Yeah. So I didn't know that.

It's so gross.

Malaria.

There's a no joke.

No, it's not. And we do know that malaria is caused by several different species within the proteus genus plasmodium. So there are different members of plasmodium which require both a mosquito and a vertebrate to complete their life cycle of this proteus.

In vertebrates, the parasite develops in liver cells and goes to infect the red blood cells, bursting from and destroying the blood cells with each asexual reproduction cycle. Yeah, which is nuts here.

The other one is called trypanosoma, which is a big one, which is a sitzy fly in Africa related to flies in South America, and is a phalanged endoparasitic responsible for the deadly disease, nagana, and cattle and horses, and for African sleeping sickness in humans. So it causes one thing in cattle and horses, and then something completely different in humans.

glycoproteins with each infectious cycle.

So the trypanosoma has thousands of possible antigens, and with each subsequent generation, the protein switches to a glycoprotein coating with a different molecular structure.

I feel like this is where we've lost people. They're like, okay, what?

So it's capable of replicating continuously without the immune system ever succeeding, and clearing the parasite is the important part of all that. So we're like a virus. You know, your body recognizes a virus because it's a protease, because it is like an animal-ish thing.

Yeah.

It's changing. And that one, trypanosoma is, or trypanosomes, they just keep changing and can't figure it out.

We're in disguises.

Right, yeah. And so there's also plant parasites that we have that causes a bunch of different mildews.

They're like the brain-eating amoebas.

For protease?

Yeah, well, I think that's a protease.

Yeah, I guess true.

Yeah, like there's some brain-eating ones that you get from like the water or raccoon poop.

So another function that they serve, which is, this one's actually important, diseases, maybe not so much, but population control, I don't know.

Yeah.

But decomposers. So again, because they are a catch-all, there are protease.

That's important.

Yeah. Also, there are fungus-like protease, saphrones, which are specialized to absorb nutrients from non-living organic matter, such as dead organisms or their waste. For instance, many types of, oh gosh.

Well, I said the slime molds and the water molds.

Well, it's the oomycetes. Oomycetes, do you remember those? There's like the oomycetes and the oomycetes grow on dead animals or algaes.

Saphronic protease have an essential function of returning inorganic nutrients to soil and water. So that one is important.

Decomposers are always important.

Always, always, always. Well, minus some, well, I want to say all decomposers are important. I guess they're important, whether we want them around or not is another question.

Yeah. Okay, so why are these guys important? Okay, so we have the decomposers and everything, but protease also play an important role within the environment because scientists are saying that of the plant-like ones, the plant-like protease produce almost half the oxygen that's found on Earth through photosynthesis.

That's crazy, because they always say it's from the plants in the ocean, but they mean like the phytoplankton.

Yeah, the protease of it. So while we're running around trying to save the trees, save the protease, yeah. Save the phytoplankton.

Yeah, right? So not only acting as decomposers and help in recycling nutrients to the ecosystems, and of course being food, they supply a heck of a ton of oxygen that we need. So that's the importance of them.

Literally couldn't survive without them.

Yeah, I mean, minus the disease part of them, we could probably survive.

Well, that we wouldn't survive.

Literally. Yeah, literally.

But life on Earth essential. They are essential to life on Earth, because at least at the oxygen, at the very least.

At the very, yeah. Why are you important? Ah, the oxygen of it.

Still.

Eh, small things. So anyway, is there anything else you wanted to add? I know we're going to keep this episode short, but like we were saying before, it's either we go a deep dive, and it's just so different.

So either deep dive, or keep it at a surface level.

And a deep dive about the specifics.

Yes, of each and one of them.

Right, which I think, again, like we can, just like we dove into Fungi, that's fine. And we're going to keep, dive into some other things.

And we're going to keep doing these guys too. So yeah, we didn't want to like totally, because you guys might be thinking, well if you guys didn't have a whole lot of content for this one, why'd you throw it out? Well, because we can't talk about it in depth.

Like we can't talk about, we can't go down to that next level, if we didn't already give you the overview of it.

We need to give you guys the base knowledge.

Yes, right. Or else whenever we say, oh it's a protese, you'd be like, what the heck is that, Katie? Like that doesn't make any sense.

Well, we've already told you what it is.

Please see episode this one.

Protese. Because we can't keep track of any of these anymore. We're too far in now.

Alright, did you have anything else?

Actually, that was your, no, that was their daily dose of science for the day. Probably, I think, probably for the week.

For the week.

There were just the word glycoproteins, probably made some people's eyeballs glaze over.

It's important, though. It's important. Alright, everybody, go check us out on Patreon and support us so we can keep talking about glycoproteins.

Yeah, but we do have, we have a guest coming up here soon, and multiple guests coming up.

Multiple guests coming up. We have a lot of fun things planned, so go check us out on Patreon. Support us, because then we can get better equipment, better platforms for online, for hosting and everything, hopefully.

So, yeah, go support us, and then we can just keep bringing you more things not about glycoprotein. There you go. Support us so you don't have to hear about glycoproteins again.

Alright, talk to you guys all next week.

Bye everyone.

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