Science Friday - Iowa Derecho, Showering And Hygiene, Parasites. August 21, 2020, Part 2

Episode Date: August 21, 2020

Dealing With The Aftermath Of Iowa’s Devastating Derecho  It’s been more than a week since the state of Iowa was hit by a surprise visitor: a line of thunderstorms with unusual power and duration, known as a derecho. The storms swept from South Dakota to Ohio in the course of a day. At its most powerful, the derecho hit Iowa’s Linn County and surroundings with hurricane-force winds amid the rain. Crops like corn and soybeans were flattened, while thousands of homes were damaged—if not completely destroyed.  Ira talks to Iowa Public Radio reporter Kate Payne and University of Northern Iowa meteorology professor Alan Czarnetzki about the devastating effects and unpredictable power of last week’s storm. An Argument For The Benefits Of—Not Bathing COVID has us all taking personal hygiene a lot more seriously these days. But for some, staying home during the pandemic has them rethinking their hygiene routines, including not showering. If the idea of not showering every day makes you feel icky, how about not showering for years? Writer James Hamblin says he stopped showering five years ago and never looked back. He says his skin has never been better, thanks to his healthy, well-functioning skin microbiome.  In his new book Clean: The New Science of Skin, Hamblin challenges the conventional wisdom about staying clean, and digs into the history of why we started showering in the first place. He discovered our modern notions of cleanliness have more to do with marketing and advertising than what’s really good for your skin. Hamblin joins Ira to talk about breaking the rules when it comes to cleanliness and discovering the benefits of skipping that shower.  Should We Conserve Parasites? Some Scientists Say Yes The idea of a parasite—an organism that needs a host organism—has always captured our attention and has been the theme of countless movies, from the sci-fi horror film Alien to the Oscar-winning movie Parasite. But a group of scientists say that parasites undeservedly get a bad reputation, and that some of them should even be conserved. They published their 12-point parasite conservation plan in the journal Biological Conservation. Parasite ecologist Skylar Hopkins and museum curator Kayce Bell, who are both authors on the recent article, talk about the role of parasites in the ecosystem and how a conservation plan might work.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. It's time to check in on the state of science. This is KERNO. For W.WIS Public Radio News. Local science stories of national significance. Last week, the Great Plains in Midwest had a surprise visitor, a powerful chain of thunderstorms known as a Dirachio. It started in the Dakotas, roared east over nearly 800 miles, eventually tapering off in Ohio. The ratios are not new. They can happen a couple of times a year in some parts of the country, but this storm was unusually powerful. At the height of the storm, more than half a million people lost power.

Hardest hit was the state of Iowa, where one county, home to the state's second largest city of Cedar Rapids, is still reeling. A week after the storm, tens of thousands of residents of the state were still without power. More than 8,000 residential buildings were damaged or destroyed, and it all happened with all. almost no warning. Here to talk more about the Deraecho's aftermath and how it happened in the first place are my guests. Kate Payne, a reporter with Iowa Public Radio based in Iowa City. Welcome to Science Friday.

Thank you. And Dr. Allen Zarnetsky, a professor of meteorology at the University of Northern Iowa in Cedar Falls. Welcome to the program. Nice to be with you. Kate, you've been reporting daily on the aftermath of this storm in Iowa. But take us back, would you, to the day it came through. What was it like?

to experience the full force of this storm system? Yeah, so Monday morning, this storm, ferocious storm, really caught so, so many Iowans off guard entirely. I've talked to multiple people who said they had a vague idea it was supposed to rain maybe that afternoon, but absolutely nothing, like what we saw. Some of the latest estimates from the National Weather Service is estimates of wind speeds of up to 130 miles per hour.

That's comparable to the category four hurricane. There were warnings that were coming down from the National Weather Service, from TV meteorologists saying this is a severe storm, but so many people had no idea, no idea what they were in for. At one point in Lynn County, one of the hardest hit counties, 97% of people were out of power in that county. There was no self-service, no internet, of course, no power. Some buildings, the roofs are entirely peeled off of the buildings while people were trapped inside.

So far, we know of three deaths in this state from this storm. We still don't know how many people have been left homeless, and hunger is a real issue. We've heard lots of stories of people also struggling to get insulin, to get diapers for their babies. It's been incredibly difficult for people here. And you went out and reported and talked to people on the scene. Yeah, and one of the people that I met is a man named Kobinale Luishi, and he lives in an apartment complex that is primarily home to refugees from all over the world. He was at work when the storm hit, but his pregnant wife and their two children were inside the apartment complex on the top floor.

The roof was entirely torn off around them. He told me he thought that his entire family was going to die that day. Seriously, it was a bad day. I can never forget that day. The way I was like, I want to lose all my family. His wife actually gave birth to their newest child two days after the storm, which is incredible, but that they've lost absolutely everything they own. He told me, this is what I own, a clothes on my body, a few diapers, and that's it.

And this came during prime crop growing season, did it not? Yeah, and we know something like 10 million acres of crops have been destroyed. The images are incredible. Cornstalks totally snapped, flattened, and enormous grain bins crushed like aluminum foil, just crumpled with grain spilling everywhere. And that, of course, will have incredible long-term economic impacts on the state. but certainly the immediate impacts is the humanitarian crisis that is happening here. Alan, how is a derachio different from twisters or even severe thunderstorms?

Well, a dericho is a type of what we call a mesoscale convective system. Mesoscale means middle and size, and so they're smaller than a low pressure system that might produce a snowstorm, for example, but they're bigger than an individual thunderstorm. You can get strong winds near the surface for a variety of reasons. The gustiness of the wind on a summer afternoon, for example, is produced by rising and sinking thermals of air. What they do is they tend to push faster winds above us down to the surface. But another way that you can get strong winds near the surface, and this is peculiar to thunderstorms, They're produced by air that is falling downward because of precipitation that's dragging that air downward.

And so when that air hits the ground, it's redirected sideways, much like you take a garden hose, the stream of water pointing it down at your driveway. When the water hits the ground, it doesn't simply stop, but it gets redirected out sideways. The leading edge of that advancing really fast wind is what we refer to. as a gustrum. And gustrants are common to most all thunderstorms. But again, in the case of a ratio that gets enhanced by environmental conditions that are on a particular side of the first thunderstorms. But most thunderstorms eventually peter out much faster or the squall line moves through and they're over with. How did this one move so far and stay strong for so long? Well, it did start out as somewhat benign looking thunderstorms over South Central South Dakota.

They slowly started to move east. The initial storms kind of dissipated, but they did go on to produce some severe thunderstorm warnings about 250 in the morning. But they, for the most part, were looking somewhat ordinary. They were holding together. They were getting bigger. The winds on August 10th were fairly uniformly out of the west, as you go from the surface upward.

And so the thunderstorms were being directed or steered along by those upper-level winds. And as the storms moved along, they started to run into more and more favorable weather conditions that not only kept them going, but caused them to intensify. That's really interesting, because I would have suspected that there would be more tornadoes.

There was only one little tornado in the whole system and not even in Iowa. Why did we not see? see this form into tornadoes? The ingredient that tornadoes really need is strong wind shear. What that means is that the wind speed and direction changes dramatically when you go from the surface upward. And the best way to get strong winds in the upper atmosphere is to have the jet stream

in the vicinity. The jet stream kind of meanders north and south over the course of a year's time. And generally speaking in the summer, that flow has drifted more forward. So it tends to be in southern Canada. Our winds aloft are not especially strong. And without that strong wind shear, it's more difficult to generate tornadoes. So it wouldn't be unexpected that this system really didn't have much in the way of tornadoes thunderstorms, and yet it produced a surprising amount of damage.

Kate, I know you have a background that includes reporting in Florida, which is hurricane country, and I noticed when you compared your analogy was to a hurricane. Yes. Is it fair to compare the kind of damage Iowa saw it to the aftermath of a hurricane? Or what was different? You've been in both places now. To me, when I first arrived in Cedar Rapids and saw the destruction, I absolutely thought this looks like the aftermath of a hurricane.

And if you go and watch some of the videos that people took from inside their homes as the storm blew through, it's almost these whiteout conditions of this incredible wall of wind, blowing rain, and you're just seeing anything being blown apart. One of the issues, I think, with this whole disaster is people's lack of familiarity with the term Durachio. I myself had never heard it before last week. And many Iowans as well were not familiar. And so a hurricane is, it's a concept that people can grab onto and conceive of to explain

just how much damage there is with, again, just a few hours of notice. That's the other point I was going to ask with a hurricane. We have all these hurricane watches when you're in Florida. You watch them come up with the Caribbean for days in advance, and this gave almost no warning. Yes. And I think that's part of why we've been seeing such a delay in the humanitarian response. The first overnight shelter was opened in Cedar Rapids on Friday,

the storm hit on Monday. There was not enough notice for a storm like this just because of its nature. With a hurricane, again, everyone has potentially days in advance. Governments can pre-position utility trucks. You know, Home Depot can send in generators. FEMA is aware of what is happening. We did not have that opportunity with the storm. Alan, do you think we're going to see more deret shows?

And if so, do we need a better predicting formula for these? Well, I don't know that we have a clear indication that there has been a change in the frequency of ratios. They have been around pretty much forever. As far as climate change, some of the conditions that we anticipate, the warming near the Earth's surface, that alone would be a contributing factor in that it would tend to destabilize the air. And unstable air is very favorable for the production of strong updrafts and down drafts and the damaging winds. But other conditions that would result from warming probably are counterproductive. Generally, it's thought that the faster winds in the atmosphere, the upper levels, would shift

more forward, and that wouldn't necessarily then work in conjunction with the lower stability air at the surface. And so, you know, it's a straightforward question, but something that has an uncertain and a complex answer. And one of the challenges with these weather systems is that they can form both in the present of what we would call weak forcing as well as strong forcing. Like people, sometimes exceptional storms are born from humble origins, and that did seem to be the case with this particular storm. And other challenges, in their early stages, they often resemble other types of convective weather systems. And it's my understanding, Alan, part of the definition of a dero is it has to travel.

so far at a certain intensity. And so definitionally, it's something that you can only recognize after it's happened, right? Exactly, right. It's an example of a weather system that's not born with that identity. They start out as more ordinary thunderstorms, and many of them turn out to produce very little damage, but rather this is something that, again, taps into conditions that just paused that downburst wind to get focused in a particular channel, and you end up with

the kind of damage that we saw. Well, I want to thank both of you for taking your time to talk with us about this. Kate Payne, a reporter with Iowa Public Radio based in Iowa City, Dr. Ellen Zarnetsky, a professor of meteorology at the University of Northern Iowa in Cedar Falls. Thank you both for taking time to be with us today. Thank you. Coming up after the break, we'll talk about the benefits of not showering during a pandemic, all about your skin coming up after this. This is Science Friday from WNYC Studios. This is Science Friday. I'm Ira Flato.

These days, now that I'm working from home, my morning shower routine is really the only thing that gets me feeling like the day has begun. I mean, one day to the other, feels like all one day, right? So without the daily ritual, I risk kind of feeling unmotivated and unclean. But for some, staying home during the pandemic has them rethinking their hygiene. routines, including not showering. Hey there, Seifre. I want to say that I do shower less often, which I think is a good thing, and I don't wear deodorant as often as I used to.

I am showering less because I don't go so many places. I also changed my hair routine to using baking soda and apple cider vinegar. I'm very happy with the results. My hair is soft and feels even more clean. Thanks to listeners James from Denver and the Margaret from California for sharing their stories with us via the Science Friday Vox Pop app. If the idea of not showering every day makes you feel icky, how about not showering for years? Writer James Hamblin says he stopped showering five years ago. Imagine the gook and the grime caked on the skin after all that time, not to mention the smell. But no, Hamblin says

his skin has never been better thanks to his healthy, well-functioning skin microbiome. So joining us now to talk about the benefits of not showering and the future of medicinal products for our skin is James Hamblin, staff writer for the Atlantic, author of the new book Clean, The New Science of Skin. James, welcome to Science Friday. Thank you so much for having me. I have to admit that this is a strange topic to be talking about right now with all the focus on hand washing and sanitizing. But you were questioning the benefits of these hygiene rituals for years before the coronavirus hit. Your first line in the book is actually how you stopped showering five years ago. When and why did you stop showering?

Yeah. It's something that I have been dabbling with for a very long time. And I started working on the book years ago. So I should say I never stopped washing my hands. That's very important. That is an evidence-based behavior that saves lives. And that's not part of anything I'm questioning here. and I still occasionally rinse up with water,

but showering in the traditional sense, washing your hair, using a bunch of body wash, using moisturizers and deodorants and anything else, has gone away. And that came together in my life for complex reasons, part of which was just reporting on the science of it, on the skin microbiome, which about five years ago I started seeing a lot of scientific papers

on just how many microbes were all over us, very similar to what's in our gut. And that kind of made me question what, what is the point of a lot of what I thought was good and necessary? And what of it could possibly be left behind and save time and money and water and plastic bottles and just simplify things? You have a medical and public health background.

So tell us why you, using soap and other products on our skin, they don't help us very much as much as we think they do. Well, you know, it's a tool like anything else, like a medication or like a hammer. On your hands, soap is an excellent tool. And if you have something grimy or greasy, you know, some oil on your skin that you need to get off,

soap is a great tool for that. But just like everything in medicine and health, more doesn't mean better. And just because it's good on your hands doesn't mean it's good everywhere. You know, if you suggest to someone that they put hand sanitizer all over their entire body, it would find that ridiculous. And I think of soap similarly. And, you know, I think most people probably have fine, healthy relationships to showering,

but there are also people who who overwash and strip the oils from their skin to a degree that dermatologists recommend that they cut back. You know, the first thing that people talk, about, right? I'm sure you've been asked this. The first thing that people want to know is how much do you smell after not washing for five years? Yeah, that is a concern. So I wash, I rinse off. I just don't use soap on my body or shampoo on my hair or deodorant. I think it's a gradual process. So everyone has the experience of having gone a day or two or three without showering. and people, that's the gut reaction is I know what that's like.

I feel gross. I look gross. I smell gross. It doesn't work for me. But in my experience, and I'm far from alone in this, everyone who has gone a minimalist route, it happens gradually. You just sort of wane yourself off. Either people are taking shorter showers, using less products, using fewer products,

using less of those products. And over time, over the course of months and years, your body, just sort of adapts. And the idea, at least, is that you are reaching a steady state with the oils that your skin is secreting, the microbes living on your skin, where you just sort of, the whole environment is less volatile. So you do smell. Humans naturally smell, but you don't smell objectionable. You don't have a classic body odor type smell. Let's talk about the microbes on our skin, because you're right that like the microbes that fill our guts. The microbes on our skin rarely cause disease. If anything else, they may help

protect us from disease. Tell us more about that. Yeah, I think it's a similar concept. And this is, this is very much emerging science. But the basic theory is that I always used to think, if there are germs on your skin, you know, microbes, you just want to get them off. And the point of showering is to just remove them all as many as possible. And once we got this sequencing technology to kind of begin to learn about the microbiome, we saw that the skin is never without microbes. There are many, many microbes all over us all the time. And so the point can't be to sterilize ourselves. You'd have to bathe in iodine or something like that. And even right when you got out, you'd be repopulated again. So similar to the gut microbiome, we don't know how to do that.

this exactly, but you ideally want a diverse, harmonic, well-balanced system in you. And we do know that simply trying to eradicate the microbes in your gut or on your skin categorically is not the best approach. And so that's why you say we're overwashing ourselves. We're too concerned with having these microbes on our skin when we don't realize that some microbes are good for us. Yeah. I think not everyone is overwashing, certainly, but that we should think more strategically about it. You know, it's like saying we're taking too many medications. You know, obviously many people are taking medications that are that are lifesaving and important to them, and we just need, many of us could be more strategic about why exactly we're doing

what we're doing. And our hygiene practices, you know, really necessary or are the things that if we don't, if we don't enjoy them, if they don't bring us joy, could we do less or go without them? Let's talk about efforts to turn bacteria on our skin into drug delivery systems. Yeah, that's one of the exciting things. So toward the conclusion of the book, I tried to figure out where this is all going. We have basically had the idea for 100 years that you just want to get all the microbes off your skin. Now we're just starting to underskin that, you know, maybe the goal should be to have a healthy balance of non-disease-causing microbes on your skin.

So how do you do that? And some people are, you know, this is not supported by evidence yet, but selling skincare products that are labeled as probiotic or prebiotic, similar to the products you see for the gut. And drug companies are actually working on selling what would technically be. a probatic of bacterial creams or sprays, topical drugs that are essentially genetically modified bacteria that can deliver drugs like you might want to help you modify, say, eczema, such that, and this is all still very hypothetical, but that if the skin is populated with these microbes, they would stick around longer and deliver an active compound to the skin. in a way that would make the person not have to be constantly reapplying something.

But we're talking about GMO bacteria here. How do you convince people? Yeah. When you talk to people who have lived with severe eczema or other sort of inflammatory skin conditions, there are, there's a lot of frustration right now. So people are pretty open-minded to approaches because we have really not proven able to cure eczema, acne, psoriasis, things that people, for some people are major deals in their life. And so this is, you know, the science is not there yet to say that this will definitely happen, but the basic concept of shifting our microbes, of trying to shift the ecosystems, repopulate. move things around is a conceptual change in how we'll approach these diseases that is exciting. Is there any evidence that we are washing away some of the beneficial bacteria that might be overcoming some of these skin illnesses you're talking about? I think it's more likely what we're doing when we aggressively wash.

And when, you know, people who are fighting, you know, bad acne as I have tend to get into cycles of just really doing more and more, using more products and washing and washing, is you're at least changing the amount of oil that's on the skin, which serves as a sort of soil that feeds the microbes on which they live. So when you change that, you change the ecosystems. You're never getting all of the microbes off of you, but you can shift their balances and change the soil in which they grow. And we know that changes in the proportions of microbes do,

correlate with flares of these skin conditions. Is it possible that the biome on our skin is also interacting with the microbiome that's inside our gut? Nothing would surprise me at this point. You think you might be exchanging them back and forth, right? We wash our hands, we wipe ourselves after we touch our mouths, we go to the bathroom, we exchange bacteria all the time. You would think that somewhere, there's some sort of conversation going on.

Yeah, yeah. I think that's totally, totally possible. And one of the things that we overlook, often we're talking about this, you know, skin health is we tend to think that it has to be addressed or created with topical products or by doing things that are modifying just the skin itself. But we know that when people change their diets, when you're feeling less stressed, when you are sleeping better, these things affect the functioning and appearance of our skin. So it is really all one complex dynamic system, the body. There's a scary part in the book that I had not heard about, and that's something called a super fungus, you write, that no one even knew existed until a decade ago, but has emerged as one of the CDC's top concerns. Candida Oris, did I pronounce that correctly? Yeah, that was something that was starting to get a fair amount of attention for being picked up in.

the bloodstreams of people just before the pandemic of coronavirus and now who's kind of taken a back seat. But the idea that we, you know, this is not to suggest that the microbes that populate our skin are good or bad or that we should give up on trying to identify and eliminate the disease-causing ones, but that the microbes evolve as we are taking more antibiotic. and we are trying to treat things, and new pathogens are rising constantly. And so it's an area of science where, unfortunately, we can't just say skin microbes are good or bad. And there will always be new challenges, and we'll have to be vigilant.

I'm Ira Flato. This is Science Friday from WNYC Studios. In case you're just joining us, we're talking with James Hamblin, staff writer for the Atlantic, and author of the new book Clean, the new science of skin. And this is a great read. It's got all kinds of historical stuff about soaps and the evolution of the soap industry. I never realized how far back soap goes and how it has the meaning of what it means to be clean

has changed over the years. And you say that the skin care industry is growing, not shrinking. So why do you expect people will eventually discover the benefits of doing less with their skin? I'm not certain we will. The industry has successfully sold us more and more products and grown year over year for a long, long time. In the middle 20th century, it was just normal for a family to just have one kind of bar of soap that would do everything for every member of the family. And now showers and bathrooms are lined with many, many different products.

And we have products segmented by gender and age and skin type and what colors and sense we like. And the shift that's happening recently is that people are wanting products that are milder or have fewer ingredients or more, quote, unquote, natural. So it does seem like these are often expensive luxury products. And the fact that people are investing in them means that the industry grows. But it doesn't mean that people are taking the same sort of clear cut, the forest approach, to the skin that we were in recent years. Do you think that COVID-19 and people who have changed their habits due to being at home all the time and change their cleanliness habits, washing, showering, whatever, do you think these things will last past the pandemic?

I wouldn't be surprised. I think it's a time when people are being more vigilant about, you know, where they're, directing their breath and how we're covering our faces and not going out when we're sick and washing our hands. And that is the sort of thing that is really important we should have been doing all along. You know, the idea of being on an airplane with someone who's coughing right next to you is terrifying right now and that we probably should have been the case before that we just stayed home and we were sick and that we were really vigilant about handwashing in a way that we are now. At the same time, people are working from home.

They're feeling comfortable discarding a lot of the practices that they might have been doing just so they, you know, because they felt it was necessary in order to go to the office or because everyone does it. And so that includes, that includes showering and people are getting to a place where they're really just doing what they find to be beneficial to them. Well, I have to tell you that after reading your book, I've been reading it for about a week and I have changed my showering habits. You have. I have. I mimicked something that you said in your book and that people were washing only their private parts and leaving the soap off their large major areas.

Yeah. And, you know, once we start talking about those things, it turns out that's kind of what a lot of people do. The billboards with people whose bodies are fully lathered from head to toe are made to sell a soap. And when you get down to it, a lot of people are just the armpits, groin, maybe the feet. The book is called Clean, the New Sondon, Science of Skin, James Hamblin, staff writer for the Atlantic and author of the book. You can check out an excerpt of the book on our website, Science Friday.com slash clean.

James, good luck with the book, and thank you for taking time to be with us today. Thank you so much for talking with me. We're going to take a break, and after we come back, we're going to talk about parasites. If you didn't hear enough about being clean, organisms that rely on a host and why some scientists say they get a bad reputation. I might even need a conservation plan coming up after this. This is Science Friday. I'm Ira Flato. Parasite won the Oscar for Best Movie last year, and why not? Movies have always played on our fears of parasites. Whether it's an alien, cocooning inside your body and bursting out chasing us around the spaceship, or pods ready to snatch your body when you fall asleep.

Please listen. If you don't, if you won't, if you fail to understand, and the same incredible terror that's menacing me will strike in you. Despite the horror of the parasites in invasion of the body snatchers and the Hollywood representations, a group of scientists says real parasites in nature get a bad rap, and we should even consider protecting and conserving them. That opinion was published this month in the journal Biological Conservation, which outlines such a plan. My next guests are here to make the case for parasites,

And they're both authors on that article. Skyler Hopkins is an assistant professor of applied ecology at North Carolina State University in Raleigh. And Casey Bell is assistant curator of terrestrial mammals at the Natural History Museum of Los Angeles County. Welcome both to Science Friday. Yeah, thanks for having us. Thanks. It's good to be here. Skyler, so you think that parasites don't deserve a bad rap?

Yeah, so, of course, you know, everyone thinks that parasites are gross, and that's okay. You know, a lot of people think that earthworms are slimy, but most people probably realize that we need some earthworms in our gardens because they're good for the soil, right? So we know that parasites are kind of gross and yucky, but they're playing important roles in ecosystems. Casey, I imagine you agree. That's right.

I think parasites, they might have a bad wrap, but they have a lot of things that they can contribute. So it's important to keep them around. Has anyone ever tallied up how many parasites are out there? It's something that's hard to estimate because there are many species that we haven't identified yet. And so our best guess is that there are probably millions of parasite species, alone that are parasites, are distributed across 15 different animal phyla. So it's this really hyper-diverse group.

And we're not exactly sure how many parasite species are out there. Skyler, your group came up with a 12-point plan for conserving parasites. Please give me your reasons why we should conserve parasites. Sure. So you can use two different arguments. What would be about intrinsic value? So if we're going to argue that species have intrinsic value and so they should be conserved, then we should be conserving parasite species.

So something like 40 to 50 percent of all animal species are parasitic. So that's a really big portion of global biodiversity. And so that has a lot of intrinsic value on its own. There's also the utilitarian argument, which is that parasites do things for us which are important. So, for instance, we know that parasitoid wasps are parasitizing and controlling insect pest populations. And as adults, they also do so pollinating. So they are saving us billions of dollars per year in the agricultural sector. But can you make a case for parasites that do affect human health and cause disease the same way you're talking about those parasites?

No. So we certainly don't advocate. for conserving human parasites. So there's a list of about 1,400 parasites and pathogens that are known to infect people. And that is just a tiny drop in the bucket of total global parasite biodiversity. And so we think that those parasites that infect people should certainly be controlled. And we're talking about parasites in wildlife that don't infect people. So you have to determine the difference between a bad and a good parasite and and choosing what to conserve.

Yeah, I would say that that's true. How does a conservation plan work? What does it look like? Do you go pick parasites and put them in jars, or do you leave them on their hosts? Or what do you do with that, Skylar? Yeah, so our overall plan has 12 different steps, and they're divided into these four different themes or categories.

And so one of those themes is just data collection and synthesis. So we just need to know more about the parasite species that are out there. And we need to do a better job of using that data to understand the threats that parasite species are facing. The next part of that is risk assessment and prioritization. So once we know what parasite species are out there, which ones really need are conservation efforts? For instance, we know that parasite species that are really specialized to use host species

that are endangered are probably also endangered because if their host species decline or go extinct, then they're likely to decline or go extinct. think this well. And so how do we figure out which parasite species are at risk? And then can we put them on red lists, like the IECN red list? And then once we know what parasite species we're trying to protect developing conservation practice to do that, so can we develop protocols so that when we are dealing with endangered host species, we don't accidentally wipe out the parasite species that use that host species. So that's something that we accidentally did with a California condor. And we brought it into captivity, we de-losted, and we probably drove one of its last species extinct. So what are the

protocols that we can develop to avoid doing that in the future? And then finally, there's education and outreach. So we just need more people to know that parasites are playing important roles in ecosystems. And so we can do a better job. New museums in K-12 in college education and also just educating conservation practitioners that, you know, parasites are gross. And they do harm their host species in many cases, but they are important parts of ecosystems. Educate me why de-lausing the California Condor was a bad idea if you're getting rid of a parasite that's attacking a bird. I think it really depends on what the parasite is doing. So in many cases, even though a parasite is using some of its host resources, it's not really using enough

resources to cause noticeable harm to that host species. And so in the case that the California a condor louse. That louse, you know, might not really have been doing anything to the birds, but we got rid of them anyways just in case. And so that might have been a just in case step that we didn't need to do. It's also important to note that getting rid of all of an organism's parasite species isn't necessarily a good thing for that organism. So we know that, you know, every animal evolved to interact with parasites. That's why we had immune systems. and if you take away all the parasite species, that immune system might not be functioning properly, or maybe when you put that host species back out in the wild again,

it's going to have problems because its immune system isn't working properly or because it doesn't have any parasite species and suddenly it's being exposed to a lot of parasites in the wild. Casey, Bill, I know you studied ground squirrels along with parasites. Please, tell me what the relationship is between these two organisms. Yeah. So lately my research has mostly been on chipmunks, which are a type of ground squirrel, and they're ectoparasites, so the sucking lice that live on the outside of them, and their endoparasites, the nematodes that live on the inside. And my interest in this is studying how they have co-evolved or how easy it is for parasites to move among different host species. And this is kind of coming back to some of what Skyler was talking about in trying to understand these natural relationships that have evolved, and if things have co-evolved over long periods of time, they've probably evolved to this level of tolerance almost. Well, they might not be good for the chipmunks or okay. They're probably not actually inflicting that much damage. So sucking

lice are actually similar to the head lice that humans have, and they feed on the blood. And yes, if you have a whole lot of sucking lice, they can cause problems. But if there's only a few sucking lice on there, they're probably not actually doing that much damage to the hosts. What can the parasites tell us about the environment that the host is living in. Tell us about how healthy it is or it's in trouble or anything like that? Absolutely. So one of the things that's really interesting that we're trying to get the message out there with this paper is there's a lot of those things we actually don't know. And so we're trying to learn as much information as we can before some of these parasites go extinct.

But one of the really important things that we can learn from parasites about the environment often has to do with what other species may be around. So a healthy functioning ecosystem requires a lot of different players, and a lot of different types of parasites actually require multiple different host species. So it will go, for example, like through a snail and then maybe another snail and then a fish and then a bird. Well, for that parasite to be in the ecosystem, all of those other host species have to be present. Otherwise, it can't complete its life cycle. So just finding a parasite can often tell you a lot about what other species are there and the fact that the food chains are actually functioning. the way that we think they are supposed to. And so to study them, I work in museums, and we take whole animals, we take the whole specimen,

and we examine it for ectoparasites, which we save, and we also examine it for endoparasites, and all of these things go together in the collection so they can be archived to learn more about these interactions and where different things are occurring. Well, Skyla, let's talk about some of the different strategies that parasites use. I understand there is a tongue-eating isopod that is really weird. Tell me about that. Yeah, so I don't study this parasite, but I think it's very cool. So it is an isopod that you can find within a fish's mouth,

and it literally chews off the tongue of the fish, and we say it sort of replaces the tongue. So the fish no longer has a tongue. If you open up its mouth, you will see an isopod inside of that. And it's very large. It's not a teeny little parasite. It is a very big parasite inside the fish's mouth. Does it take the place of what the tongue is doing,

or is the fish going to die because it has no tongue anymore? Yeah, actually, they do seem to take the place of the tongue and function. There are some studies that suggest that actually fish with that parasite may actually be more efficient at feeding, but I'm not sure that's been well supported. I just know that there's been some research looking into how well fish fare with those parasites, and they seem to do okay. You know, if you look at the movies that are out there, whether it's my favorite invasion of the body snatchers or any other movie where the parasites take over, one of the things the parasites do is that they take over your brain or they change your behavior. Do they have a type of mind control? Are there parasites that can do that, Skyler?

Yeah, so nematomorph parasites, which are sometimes called horse hair worms or Gordia knot worms, are these remarkably large worms that are stuffed inside the tiny body of the critical. And they manipulate the cricket's behavior and cause the cricket to jump into bodies of water, which is not something a cricket would normally do. They're not aquatic, right? When the cricket gets in the water, the worm will leave its body and actually become free living. So it can swim through the water and it's looking for other adult worms to mate with and continue its life cycle. And actually, those crickets that jump into water bodies turn out to be pretty important. So we know that in Japan, those crickets are eaten by these endangered Japanese trout.

I think they actually make up something like 30% of the trout's diet. And because the trout are eating these crickets, which are subsidizing the stream environment, they eat fewer of the invertebrates that are living in streams, which means that there are more of those invertebrates, which can do more consumption of leaf litter and nutrient cycling and things like that in the streamed ecosystem. And so this one parasite manipulating cricket behavior has these rippling effects through the entire ecosystem. Casey, there's a parasite that can influence an ant to change the color of its body. Yeah, that's right. So there's a nematode or a type of roundworm that infects ants. And what it does

is it gets into the abdominal region of the ant, and it turns up bright red so it looks like a berry. and then these ants actually will hang out in places that they're really visible to birds, and then birds think their berries come along and eat them, so then the nematode gets passed on to the bird so it can complete its life cycle. There's a lot of great examples like that where parasites make a host make itself more available for the next host. Pretty tricky. Skylar parasites have a complex life strategy, I understand. Lots of animals have symbiotic relationships, but how does an organism evolve from symbiotic to parasitic?

Yeah, so that's a great question as to, you know, does something become symbiotic first and then become a parasite? That it's not necessarily the same sequence of events for all parasite species. We actually know that parasitism has evolved independently many, many times in the animal kingdom. So like I mentioned, there are 15 phyla within the kingdom inamalia that contain parasitic species. And then within those 15 phyla, parasitism has cropped up again and again. And you might think that these things might start from a mutualism,

so two species sort of benefiting each other, and then one species starts to cheat and be a parasite. But that doesn't really seem to be the case, actually. It seems like cheating can just evolve on its own pretty commonly. I'm Ira Flato. This is Science Friday from WNYC Studios. Our bodies are filled with bacteria, and viruses that live off our bodies, should we consider a microbiome to be full of parasites?

Yes, so we know, of course, that our microbiome can consist of both beneficial species and detrimental species, but there is a gray area where it can be really hard to tell if an individual microbe or even, you know, a larger sort of, you know, ecosymbotic organism is really good or bad for the host. They're examples with, like, staff where a relatively high proportion of the human population has this potential pathogen on them all the time, but it is not hurting them. And for some reason, once in a while, these infections end up being very detrimental. And so, in general, the line between parasite and not parasite is a little grain and can be hard to determine.

You know, I started out our discussion by talking about how parasites, have been a source of inspiration for Hollywood. Skyler, what are some other parasites that have invaded pop culture? So we talked a little bit about the zombie parasites. There is a whole video game called The Last of Us, which is about Corticep's franchise basically taking over the human population and turning us into zombies. Also, I'm not a huge Pokemon fan.

I don't know all the details, but I do know that there are Pokemon characters, like parracek, which are based on parasite species. Casey, what do you think we're so fascinated in our culture and what we talk about by this particular host parasite relationship? I think some of it comes from being interested in things that we perceive it. There is a little bit of a yuck factor. A lot of us are interested in things that others perceive as gross. But also, I think it's kind of the same reason we're fascinated with horror movies, right?

there is this intrigue to these things that are mysterious and potentially dangerous. So at least from my perspective, there's a lot of different reasons that people can become interested in studying parasites or even just from a pop culture perspective, understanding how these foreign things could potentially impact our lives or the lives of animals or something. Well, we've run out of time. A fascinating discussion. I want to thank both of you for taking time to be with us today. Skyler Hopkins, Assistant Professor of Applied Ecology, North Carolina State University in Raleigh. Casey Bell, assistant curator of terrestrial mammals at the Natural History Museum of Los Angeles County.

Again, thank you both for taking time to be with us today. Yeah, thank you so much. Thank you. And we've got an article that shows some of the parasites we've talked about, plus some parasite-inspired anime by parasitologist Dr. Tommy Lung. It's on our website at ScienceFriday.com. That's about all the time we have for this hour. If you missed any part of the program, you'd like to hear it again, subscribe to our podcasts, or ask your smart speaker to play Science

Friday. One more thing on the Science Friday Voxpop app this week. What question do you have about the immune system and COVID-19? What questions do you still have about the immune system and COVID-19? That's on the Science Friday Voxpop app wherever you get your apps. You can also say hi to us on social media, Facebook, Twitter, Instagram, or you can email us, SciFri at ScienceFridy.com. Send us feedback. Tell us what you'd like us to cover also. Have a great weekend. We'll see you next week. I'm Ira Flato.