What Lichen Tell Us About Ecology, Air Quality, And More

IRA FLATOW: This is Science Friday. I’m Ira Flatow, live with OPB from the World Forestry Center in Portland, Oregon.

[CHEERING AND APPLAUSE]

Thank you. We can decide wherever we want to go to. We take the show on the road. And when we come to a place like Portland, we have to think, What can we find there that is unique, that we can’t find anywhere else in the country? And who are the local experts who can help us see the world in a different way?

So you look around at the towering trees and you say to yourself, Why don’t we go into the woods? And that’s what we did. And we went into the woods and we decided to explore the very often overlooked world of lichens. A lot of people don’t know what lichens are. They are a remarkable fusion of fungi, algae, other tiny bacteria, and they thrive in the misty forests of the Pacific Northwest.

And from their crucial role in ecosystems as indicators of air quality to their striking colors and forms, we’ve really taken a liking. I have never heard of this joke before. I apologize.

So we’re going to be joined by the few people who can tell us all about them and let me welcome them to the show right now. Right on my left is Hannah Prather, postdoctoral researcher and visiting assistant professor of biology at Reed College, where she teaches about the relationship among lichens, host trees and the surrounding ecosystem. Welcome to Science Friday.

HANNAH PRATHER: Thank you.

[APPLAUSE]

IRA FLATOW: Jesse Miller is Lead Botanist for the Washington Natural Heritage Program, where he provides guidance for rare plant conservation efforts. That sounds cool. And studies effects of altered fire systems on plant and lichen communities. Welcome to Science Friday.

JESSE MILLER: Thanks, Ira.

[APPLAUSE]

IRA FLATOW: I’m going to start with you. Hannah, tell us how you got interested in lichens. Because I was out there with you today and you were just in your element, as we say.

HANNAH PRATHER: Yeah, this is true. Oh, it’s such a great question. When I started in graduate school, I started climbing trees. And there’s kinds of a lot more to that story, but as I was up in these big tree canopies here in the Northwest, some of our towering Douglas fir, I started to notice these little plants, or what we now know as lichens, that were occupying this really incredible three dimensional space. And I think it was sort through that connection from the canopy to seeing the things that were thriving and living up there, that I really had a lot of curiosity to ask more questions about those organisms.

IRA FLATOW: Very interesting. And Jesse, as I said, you help guide how rare plant conservation happens in Washington and Oregon. How do a lichens fit into that picture?

JESSE MILLER: Yeah. Well, lichens have been overlooked for a long time relative to animals, especially, but plants as well. We just haven’t given very much attention to the rare lichens, the lichens that are perhaps even on the edge of extinction. And so one of my personal and professional missions in life is to try to bring more attention to our endangered lichens. So that’s been a focus of mine, especially for the last couple of years since I’ve been in Washington.

IRA FLATOW: OK, so let’s begin by helping us to understand lichens’ ecological niche. I mean, they have one, right? And of course, we say they. And you were telling me, Jesse, that the plural of lichen is lichens, right?

JESSE MILLER: Exactly.

IRA FLATOW: That’s the correct way to say it? Do people get it wrong?

JESSE MILLER: Yeah. People say, “All the lichen out there,” like it’s some amorphous mass. But there are a whole bunch of different lichens out there and we need people to understand that. It’s very important.

IRA FLATOW: And why are they important? What is their niche in nature?

JESSE MILLER: Sure. Well, lichens play a lot of important roles in ecosystems. For one thing, a lot of animals use lichens as a food source or nesting material. There are all kinds of invertebrates that live inside lichens. But lichens also play roles in nutrient cycling.

They stabilize soil. They play roles in hydrological dynamics. So if we lost some of the lichens in our forests, the casual observer might not notice, but the forest would notice.

IRA FLATOW: Yeah. And I know that you focus on lichens that are, quote, “on the fringe.” Right? What do we mean by that?

HANNAH PRATHER: Yeah. Well, my background, my PhD research was looking mostly at urban lichens. So how these communities of lichens and these tall tree canopies, how they’re being affected by the urban condition of urbanization, the transfer of air pollution, things like this. A second part of my work took place on the Western Antarctic Peninsula, a place of rapid warming on the globe. And so we were looking at lichen and bryophytes, mosses, in those communities and how they’re changing really dramatically with warming effects in that area.

IRA FLATOW: Are they significantly different from the kinds we would find around here in Oregon? If you looked at them, you say, Oh yeah, they come from the poles?

HANNAH PRATHER: Certainly. Antarctica has a beautiful flora. There are certainly things that are endemic only to Antarctica, but there’s also cosmopolitan species that occur everywhere. So it was kind of an interesting blend.

IRA FLATOW: We were out in the forest. You were showing us lichens, and people were asking, Could this lichen grow differently if there weren’t air pollution? Does air pollution affect the growth of lichen?

HANNAH PRATHER: Yes. And many of us might have heard of this sort of lichens can be this canary in the coal mine, right? They are these bioindicators, something that’s naturally in an environment, but can also give us a lot of information about the condition of that environment. So we know that lichens respond pretty quickly to things like air quality pollutants.

And one of the main ways that we see this is in their morphology, so the size of the lichen. Lichens don’t have protective mechanisms like vascular plants do. They don’t have a waxy outer surface or stomata that can regulate gas and surface exchange. And so because of that, they’re these little sponges in the environment.

So when things land on them, they actually absorb that fairly easily, if they’re hydrated. So the morphology is kind of one way that they can limit the surface area exposure to pollution. So often in urban areas, we will see lichens that are tolerant of urban conditions. And if they aren’t tolerant, they might shrink their size down so that they have less of that surface area touching the pollution.

IRA FLATOW: Right. Jesse, you’re nodding in agreement.

JESSE MILLER: Yeah, absolutely. And when you go out to a forest with really high air quality, many miles out of the city, you see a whole suite of lichens that you won’t see in the city or in any other more polluted areas. And then here in urban areas, we actually see lichen species that are indicators of air pollution, species that actually become more abundant in polluted areas. So there’s a whole story to read on the landscape out there.

IRA FLATOW: Yeah. And I know that you study the effects of wildfires on lichen, right? Does that mean just the heat effects or is it the smoke and everything that they leave behind?

JESSE MILLER: Yeah, it’s a lot of different effects. So there are direct effects. I mean, lichens often burn up in fires. That’s one of the most obvious conclusions, but not a huge shocker there.

[LAUGHTER]

[INTERPOSING VOICES]

IRA FLATOW: I hate when that happens. Yeah.

JESSE MILLER: But there are all kinds of indirect effects as well. Fires change the landscape. They might change a forested landscape to an open grassland. And all those forest lichens are not going to recolonize unless a forest grows back some decades or centuries later.

But it’s really important to recognize that fire can burn in many different ways. We have what we call low severity fires, fires that don’t remove most of the trees and other vegetation, and high severity fires that do remove most of the vegetation. And high severity fires typically have much stronger effects on the lichens.

IRA FLATOW: Hannah, do people walk past lichens and just never know that they’re looking at them?

HANNAH PRATHER: Oh, absolutely. Lichens are really good at being very cryptic. And so they often are these kind of scummy, scuzzy things that are on your roof or your driveway. You’ve probably all have tried to scrape them off. I won’t judge. But yeah, so they occupy a pretty unique part of the landscape.

They like to grow on other things. So we’ll see them on trunks of trees, on rocks, even on buildings, maybe even on your car if it’s been parked in the Northwest for a while. So it’s very common that people overlook these little organisms.

IRA FLATOW: Well, what makes them different from just moss that we see growing all over the place? What makes it not a lichen?

HANNAH PRATHER: Yeah, good question. So mosses and lichens actually like to hang out in the same types of habitat. So especially in the Northwest, we have a lot of moisture in our systems, so we see both often really together. So one of the key indicators I always tell my students when we’re talking about the difference between lichens and mosses is that mosses are ancient plants, so they always have a stem and leaves.

That’s one good way to notice them. They also have a little bit greener of a color overall, versus lichens are built of fungi. So they often have these really different morphologies. They can look a lot of different ways flat, like a leaf or threaded like a little shrub.

IRA FLATOW: Do they share the same space as the moss?

HANNAH PRATHER: Oh, absolutely. Yeah.

IRA FLATOW: So is this like a symbiotic thing going on there?

HANNAH PRATHER: No. I wouldn’t say there’s any sort of symbiotic relationship. I would say it’s more of they thrive in the same types of environmental habitats. There is a lot of work in the Northwest looking at stratification of these species across in really tall canopies.

For example, we used to have a research canopy crane located here in the Northwest, where we did a lot of the preliminary research, looking in tall trees to see how these things stratify with gradients of light and moisture. And so what we know is that mosses often like to be in the moister, low layers, low light layers of a canopy or of a forest. And lichens do like to be in the higher bits, where there’s more high light and a lot of drying as well.

IRA FLATOW: And also, do we find them on rocks? Jesse, you see them on rocks everywhere?

JESSE MILLER: Oh, absolutely. Some of the very best lichens are on rocks.

IRA FLATOW: Is that right?

JESSE MILLER: I mean, lichens will grow on almost anything that holds still. So rocks, trees–

IRA FLATOW: People.

JESSE MILLER: Yeah. It probably means you need to live a more active lifestyle if that happens.

IRA FLATOW: Is that right? Because sometimes you’ll go through and you see these rocks in the forest and they have patches on them, different colored patches. Is that what lichens are also, sort of flat, not these big, raised leafy things?

JESSE MILLER: Yeah. And those are crustose lichens, those really flattened lichens that are just totally sunken into the substrate. And those are actually some of the most challenging lichens to identify. Those are the lichens that keep us up at night.

[LAUGHTER]

IRA FLATOW: Those are the kinds that people are power washing off their rocks sometimes.

JESSE MILLER: Yeah. Some people try to identify the lichens, other people just try to power wash the lichens. That’s the world we live in.

IRA FLATOW: Well, why should we care? Seriously, why should we care about lichens? They’re so small. A lot of people don’t see them. Why should we care so much? Let me start with you.

JESSE MILLER: Sure. Well, a lot of people don’t even think about lichens or notice lichens in their day-to-day life, but lichens play all these roles in ecosystems that we don’t see. And ultimately, we’re all dependent upon the ecosystems around us. So one of my favorite examples is old growth forests in the Pacific Northwest are inhabited by flying squirrels that eat lichens as a major part of their diet.

And flying squirrels in turn are eaten by spotted owls, which are one of our great animals in the conservation history of the Pacific Northwest. So if we lost a lot of our forest lichens somehow, it would affect this whole food chain. And people see the squirrels and they see the owls, but they may not notice the lichens.

IRA FLATOW: We’ll be right back after this short break. This is Science Friday from WNYC Studios.

This is Science Friday. I’m Ira Flatow. We’re listening to a conversation I had on stage at the World Forestry Center in Portland, Oregon, in collaboration with OPB, Oregon Public Broadcasting.

We were there to talk about something they have a lot of in the Pacific Northwest, lichens. My guests are Hannah Prather, postdoctoral researcher and visiting assistant professor of biology at Reed College, and Jesse Miller, a lead botanist for the Washington Natural Heritage Program. And we had more than 300 curious members of our audience who got to ask their questions about why people are liking their lichens.

We’ve got a question from the audience. Go right ahead.

AUDIENCE: Are all lichens equally safe to touch and handle? And if not, what are the features you look for that might say stay away?

IRA FLATOW: Are there poisonous lichens?

HANNAH PRATHER: Oh, boy. OK, I’ll do my best, and Jesse, you can jump in. I’m almost afraid to go on statement here.

[LAUGHTER]

IRA FLATOW: No one’s listening, so it’s OK.

HANNAH PRATHER: Most lichens are safe to handle, I think would be a safe assumption. There are a few lichens that have toxic qualities to them. One of those is the wolf lichen. It’s a chartreuse lichen that’s often on the east side forests that we’ll see.

And it just has known to have some poisonous qualities, so you wouldn’t want to ingest it or maybe touch it a lot and touch your mouth. But for the most part, lichens are really friendly to interact with. Yeah, if you find them on the ground, you can pick them up. Can you think of any other… not really?

IRA FLATOW: So it’s not like possible poisonous mushrooms that you might pick up?

HANNAH PRATHER: Oh, no.

IRA FLATOW: No? OK. I think that’s probably what people were thinking of. Yes, thank you for that question. Next?

AUDIENCE: Well, yeah, actually, on the concept of picking up lichen, I’m a nature and forest therapy guide and we do a lot of texture stuff. And people like to bring textures back with them, and they often bring back lichen, whether it’s still attached to a stick or that they found on the ground. Are those alive?

IRA FLATOW: Yeah, we saw a lot of stuff today in the forest, a lot of lichens on sticks that were falling down. Are they alive?

HANNAH PRATHER: The answer would be yes. I mean, assuming that they are in– Lichens can die. They can start to degrade back into the environment. Often those look, like Jesse had mentioned, either bleached, so they’ve lost the algal component or they’re a little bit necrotic and reddened, meaning that the fungal partner is starting to die. And that can happen fairly quickly if it’s in a really wet, if they fall on soil and they can start to decompose back.

But typically things that are epiphytic, they like to grow on tree branches or up on other surfaces. If you bring those inside, they probably are still alive, if they’re hydrated. They can go into that sort of dormancy period if they’re dry and they can do that, again, for periods of time, depending on the species. Yeah.

IRA FLATOW: Well, when we were in the forest watching, you found a tree branch on the ground and I have never seen a scientist get so excited about finding a tree branch. What makes that so special about them?

HANNAH PRATHER: Oh, if you’re a lichenologist and you find a branch from the canopy on the ground, it’s like total gold, like you’ve hit the jackpot. Because it’s really giving us this nice snippet of what we’re seeing up overhead that otherwise would be really hard to access. You’d have to use ropes or some other technique to get up there. And so just on that one branch, Ira, we found, what? Almost eight different species, just on a very coarse look. So there’s probably many more.

IRA FLATOW: And you were happy a dog hadn’t come along and just run off with the branch.

HANNAH PRATHER: Yes.

[LAUGHTER]

IRA FLATOW: Yeah, I get it. Yes. Next question, please.

AUDIENCE: I’m curious, as we have a room here of people who are interested in lichen, what we can personally do to help encourage lichen growth and conservation? I think about when I am out in nature, and I’m trying to not walk off the trail, and thinking about what you said about lichen anchoring on soil to stabilize it. I’m also curious about cryptobiotic soils. But curious about personal responsibility, how we can help lichen, and how to encourage its growth and not accidentally kill it, or things like that.

IRA FLATOW: Any recommendations? Should you avoid walking on the lichen if you see them in the forest?

JESSE MILLER: Yeah, as far as those crusts that grow on the soil, we have a saying, “Don’t bust the crust.” So yeah, don’t walk on those crusts. That’s one smart move. But I think more broadly, just learning a little bit about lichens and learning to identify some common lichens in your area is one great step forward to being a friend of the lichens and helping them. But one much more specific thing I’d suggest, the US Forest Service is working on revising its umbrella management plan for all the forests in the Northwest, the Northwest Forest Plan.

And there are periodic opportunities for the public to comment on this. And one big question, so for many years, the Forest Service has safeguarded or tried to safeguard many of our rare lichens. It’s kind of up in the air whether that policy will continue. So I’d encourage everyone to put in a comment and say you want to see our rare lichens continue to be a priority for management.

IRA FLATOW: Yeah, it takes public interest.

JESSE MILLER: Absolutely.

IRA FLATOW: Yeah.

[APPLAUSE]

AUDIENCE: Before I ask my question, I have a lichen joke.

[LAUGHTER]

A fungus and an algae took a lichen to each other and now their marriage is on the rocks.

[LAUGHTER]

[APPLAUSE]

So when I taught in Alaska, where glaciers had receded, we told our students that you could age how long ago where the ice had moved back, especially places where there wasn’t photographic evidence, because certain species of lichen would grow on the rocks at a certain rate. And I didn’t know, I was wondering if you could speak to that.

HANNAH PRATHER: I’m not sure what else to say. It’s a really cool thing. I’ve worked in polar ecosystems and the lichens are incredible. I think it’s been a really neat part of my work, to look in areas of recent recession and see what types of species are there, what types of role they’re playing, how they transform soils early on in those processes. So it’s pretty fascinating.

IRA FLATOW: Is it surprising to see how resilient they are to live in that kind of climate?

HANNAH PRATHER: Oh, absolutely. Yeah. I think some of the interesting changes on the Antarctic Peninsula are just the change from snow to rain. And so a lot of those species aren’t able to handle having more liquid moisture.

IRA FLATOW: Interesting. Yes, step up.

AUDIENCE: OK, So I saw a video once upon a time of two lichen experts that came here to Oregon, and they were at the waterfront here in Portland and also in the gorge, talking about signs or symptoms in lichens of an unhealthy air environment. So if you know anything about that, could you get into some of the basic signs of how to tell your air quality?

IRA FLATOW: Yeah, how do you tell air quality from the lichens?

JESSE MILLER: Well, I’d say one thing to notice is just the size and stature of the lichens. In polluted places, the lichens are going to be a lot smaller. But we also have a lot of lichens that are orange in color, that grow in polluted places, and these are nitriles or nitrogen-loving lichens, pollution-loving lichens. So when you see just a tree that’s covered in orange lichens, for example, that’s a sign you may be in a fairly polluted place. And when you see a tree that’s covered in big, draping, three dimensional lichens, that’s a sign that you might be in a place with better air quality.

IRA FLATOW: I just think it’s good to know that. Yes, please.

AUDIENCE: So I’ve noticed at the Home Depot parking lot near my home, where they do a lot of leaf blowing, the trees in the parking lot are just covered in lichen. And I’ve always wondered if it’s because of the leaf blowing, it’s blowing the lichen particulates up and sticking them on to the trunk. Do you have any thoughts?

IRA FLATOW: Wow, what an observation.

JESSE MILLER: I think you could set up a really neat experiment to test this.

[LAUGHTER]

IRA FLATOW: There’s grant money here for that, I think.

AUDIENCE: I fell in love with them about 12 years ago, and just I’m obsessed with them. So, just–

IRA FLATOW: Could that be happening? I mean, serious, could that be an unintended consequence of leaf blowing? And is it a healthy thing to get more of them up into the tree?

JESSE MILLER: I think it’s conceivable, there could be lichen propagules getting into the leaves and then blowing back onto the tree. Yeah, that would be a great science or nature paper, I think, if we could prove that.

IRA FLATOW: Talk about citizen science.

JESSE MILLER: Yeah.

IRA FLATOW: Let’s everybody get– You want a citizen science project?

JESSE MILLER: But we actually are still working on developing methods. I mentioned this idea, that we perhaps should be establishing new populations of some of our rare lichens, and figuring out the exact methods we would use to do that remains kind of an open question. So I’ll add leaf blowers to the stack of ideas.

[LAUGHTER]

IRA FLATOW: Yes. Next question, please.

AUDIENCE: So, when I go to any bookstore and I to the natural science section, there are dozens, if not hundreds, of books on fungi, but two or three, if any, on lichen. So I want to why does it seem like there is such a deficit of research and cultural significance placed on lichen as opposed to fungi?

IRA FLATOW: Yeah, it needs better public relations, lichen. I mean, seriously. Right? People don’t talk about it. They talk about the moss.

That brings me to my blank check question I ask a lot of my guests. If you had a blank check and you wanted to spend it on researching or getting public– How was the best way to spend all that money? Is it studying lichens in a certain way or get publicity for it, or? Jesse, let me ask you first. What don’t you know that you want to know that you could spend that money on?

JESSE MILLER: Yeah. So we know that there are a lot of lichens that are associated with old growth forests in the Pacific Northwest, but we’ve, of course, lost most of our old growth forests, which used to cover the landscape. So one question I wonder about is, How suitable are some of our more mature second growth forests and what can we do to help bring about more old growth character in some of our forests that aren’t quite old growth, but are nice old stands of second growth? And also doing experiments to try to establish new rare lichen populations in some of those stands. That would be a priority for me.

IRA FLATOW: Hannah, how would you spend some money? I’m giving you a blank check. What would you spend it on? Anyway, anything that involves working with lichens.

HANNAH PRATHER: Yeah. I hate to piggyback on Jesse’s, but I think there’s a real– I think just living in the Northwest, and loving our forests, and really seeing the beauty of an old growth forest and the loss that we’re looking at with increasing wildfire and the loss of Opal Creek. Oh my goodness. I really think that there’s some interesting research around these types of questions that Jesse is posing.

Can we somehow accelerate those conditions back to old growth? Can we somehow bring in lichens and propagate or attach them into canopies and help re-establish that biodiversity? I think there’s a lot of interest in that.

IRA FLATOW: Interesting. Yeah, OK. Next question, please.

AUDIENCE: I was wondering, since lichens are three or more organisms, how do you begin to sort them taxonomically and describe that evolutionary relationship that some of them might have?

IRA FLATOW: Jesse, you want to begin?

JESSE MILLER: Yeah, great question. How do we define species for organisms that are inherently composed of multiple species? So the names we actually use for lichens, the scientific names, actually refer to the fungal partners. And part of the reason for that is because pretty much every unique lichen out there is a different fungus, but many of them share the same algae.

So that’s why we use the names of the fungi rather than the algae. But there are some interesting cases where that system doesn’t quite work perfectly. There are cases where the same fungus can partner with two different algae and form two totally different lichens. But because we named them after the fungi, we call those two lichens the same thing. So it remains an imperfect science.

IRA FLATOW: Do we need different names for them?

JESSE MILLER: Perhaps. That’s something that’s been talked about in the lichenological community, and I think it’ll be interesting to see where we are in 20 or 30 years.

IRA FLATOW: Lichenological, I like that. Like that. Yes?

AUDIENCE: The whole idea around symbiosis, I honestly find really romantic. And the way you’re even describing these relationships and how they meet each other, and how they have babies and all that. So I’m wondering about the– I know this is different than other people’s questions, but the sense of is poetry, or art, or the elements of that relationship inspiring some creative worlds?

HANNAH PRATHER: I will add, just on your romantic notion, that I did have a final project for my lichens course last year was a lichen outreach project where they had to spread the word on lichens and what was so great. And I had some students put together a dance about the symbiosis, the coming together of the partners, and it was actually really incredible.

[LAUGHTER]

IRA FLATOW: Wow. Where can we see that?

HANNAH PRATHER: It’s actually, I think, posted on the Reed Biology web page.

IRA FLATOW: There you go. Soon to be major motion picture. OK. Question?

AUDIENCE: I’m wondering about whether or not we see any lichens in the fossil record, and if we have any ideas about their history of evolution? Kind of a different turn from the poetry, going a little bit more hard science there, but–

IRA FLATOW: Good question.

AUDIENCE: They don’t have any hard parts. Do we see them? Do we have any ideas about when and how they might have evolved?

JESSE MILLER: Great question. So my understanding is that there are only about 150 individual lichens that have been found as fossils. So they really don’t fossilize very well at all, compared to a lot of other organisms.

So that’s one reason why reconstructing their ancient evolutionary history has been really difficult. But we do currently believe that lichens are hundreds of millions of years old. So they do go back a really long ways.

IRA FLATOW: Wow. That’s good to know. Yes, sir?

AUDIENCE: Hi. I’m really interested in how cities grow and change, and I’m really wondering whether there’s any lessons to be learned by looking at our lichen communities and how they grow and adapt to changing environments that we can apply to the way we design our neighborhoods and our cities.

JESSE MILLER: Well, great question. I think one cool example is after the Clean Air Act was passed, some lichens that were no longer growing in urban areas were actually observed to come back and recolonize urban areas because the air quality had improved so much. So yeah, I think it’s wonderful to use them as an environmental indicator as conditions change over time. Absolutely.

IRA FLATOW: That’s great. All right, one last question for the evening for the panel here. What one thing, what one message, what one idea do you want everybody in our audience to take home tonight about lichen? I’ll start with you.

HANNAH PRATHER: Well, one thing I think that has really been meaningful for me in working with students and lichens is probably that just it’s a great connection to nature and they’re so ubiquitous. So you can go right outside your door, on your city street or in a city park, and find many lichens. So I really want to encourage people to just get to know the lichens in your neighborhood. Get to be outside and enjoy those.

This is the best lichen viewing time because we’re having this stormy, wet weather. So it brings down lichens out of the canopy. It brings down branches. And so it’s a great way to just connect with nature, find some in your area, and learn about them.

IRA FLATOW: Thank you, Hannah Jesse, what do you think?

JESSE MILLER: Well, we really are living in challenging times. We are experiencing a biodiversity crisis around us, and we have to make choices collectively about how we want to address this. So my closing message to everyone is, please vote.

[LAUGHTER]

IRA FLATOW: That’s Jesse Miller, lead botanist for the Washington Natural Heritage Program, and Hannah Prather, postdoctoral researcher and visiting assistant professor of biology at Reed College. They spoke with us on stage at the World Forestry Center in Portland, Oregon, in an event we produced with OPB. Special thanks to OPB’s Jes Burns and SciFri’s Diana Plasker.

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