Radiolab - Return of the Flesh-Eaters

Starting point is 00:00:01 Wait, you're listening. Okay. All right. Okay. All right. You're listening to Radio Lab. Radio Lab. From W-N-Y-S-C.

Starting point is 00:00:14 See? Yeah. Hey, I'm Latif. This is Radio Lab. And today I have with me, a Sarah. Okay, no echo or anything? No. Okay, great.

Starting point is 00:00:27 As in Radio Lab reporter producer Sarah Kari. Can you hear me without an echo? Oh, yeah, no. You sound great. And Sarah's here in the studio. I have a Sarah. Hello. Hi.

Starting point is 00:00:36 Hi. Nice to talk to you. Sarah Zang, who writes for the Atlantic and is a wildly prolific science journalist. Oh, thank you. Like, I feel like you cover COVID. I know you cover autoimmune diseases. I know you cover OZempic. I'm sort of lucky enough to cover just like whatever I'm interested in.

Starting point is 00:00:53 But we called her up because a while back, she noticed something weird happening to the deer in the Florida Keys. I don't know if you know about the key deer. They're like really cute. They kind of like wait at bus stops and people like to feed them. Okay. And so back in 2016, a very grave situation for this endangered. People suddenly started noticing with all these like ugly, like grisly wounds on these deer.

Starting point is 00:01:16 Gaping holes or wounds in their neck or in their, in their head. Literally you could see down to the bone. gruesome, painful. It's a very sad sight. So it was, you know, it was kind of like a weird thing happening in Florida story. Yeah. But volunteers are teaming up to treat affected animals. When it turned out was that there was an infestation of an insect called the New World Screw Worm.

Starting point is 00:01:43 New World Screw Worm. The New World Screw Worm. Also known as flesh-eating worm. Oh. And like I had never heard about squirrel worms before. Yeah, me neither. I would imagine most Americans have never heard about screwworms before. And the reason we don't know about it is because it's been eradicated from our country.

Starting point is 00:02:05 I was like, what? Like, that's crazy. I've never heard of like an insect being like completely eradicated from our country. And as Sarah started to dig into this, it got even crazier and crazier. What she found was the kind of amazing story of one of the biggest environmental interventions that humanity has ever undertaken. And the story of this worm, this honestly nightmarish, flesh-eating paris. that despite those efforts is right now today back in the news. We are on screw-worm watch and we are ready.

Starting point is 00:02:41 Forcing public health officials and ranchers and ethicists. Here we are in the sixth major extinction that we humans are causing. To ask maybe one of the biggest questions that we as beings on this planet can ask. would it ever be okay to bring about the extinction of a species? Oh, boy. Yeah. But, I mean, these are about the worst parasite on Earth. I cannot imagine anything worse than these guys.

Starting point is 00:03:14 So one of the first people we called when we got into this whole screw worm thing was the author Sam Keen. My name is Sam Keen. I am a science writer. Because it turns out he, like Sarah, at some point had fallen into the screw worm hole. Yeah. I had never heard of them, and I started Googling, and then I went to Google Images, and I immediately regretted doing that. And according to Sam, the reason that none of us had ever heard about what he called the worst imaginable parasite on Earth is because of something that in 1970, the New York Times called the single most original thought of the 20th century. And it turns out that thought was born in the brain of a. a man named Edward Nippling.

Starting point is 00:04:00 Edward Nippling. So, as you know, Letif, when we first learned about this, I got obsessed and started doing some digging. Yeah. And learned that Nippling has unfortunately passed away, but... Dr. Edward F. Nippling, we're happy to be here in your home today. And thank you for participating in this oral history. I found this whole trove of interviews that he did back in the day.

Starting point is 00:04:26 If you could start, please, by telling us, uh, when. and where you were born? I was born in Portleback of Texas, March 20th, 199. Nibbling grew up on his family farm in Texas. In those days, farming was a very difficult occupation. Honestly, mostly because of the, what was I supposed to say after that? The screwworm. Oh, mostly because of screw worms.

Starting point is 00:04:54 Yeah, so it was a problem for ranchers. Actually, I think this is a quote I remember. Screw rooms used to strike fear in the hearts of ranchers all throughout the southern United States. Could we actually, could you just tell me what a screw worm even is? It is a fly. It has kind of like... Why do they call it a worm if it's a fly? Well, flies are also maggots, right?

Starting point is 00:05:14 Like, our flies come from maggots. So the maggot phase is a worm. Okay, okay, okay. So basically what they do is that if you have a little, like, knicking your skin, a little wound... Even something as small as a tick bite? These flies would lay their eggs in those wounds. Roughly 400 eggs at a time. Oh, my God.

Starting point is 00:05:31 And then these maggots essentially would come out. They kind of look like a small white thread. They have this kind of horrifying mouth with two sharp teeth and a little ridge on their body that sticks out exactly the way the threads on a screw do. They would twist themselves down. Kind of burrow themselves into the flesh, like a screw, and they would eat the flesh. Oh. Yeah.

Starting point is 00:05:56 And they are extremely hard to get out once they have locked in. A screw worm would get into the naval of calves when they were born. And so back to young Edward Nippling. He got probably the worst job on the farm, which was to pick the screw worms out of the family's cows. And that was a very unpleasant task. Have to try to yank them out of these animals that obviously aren't happy about this. Is there a tool you used? I'm guessing a tweezers or just fingers.

Starting point is 00:06:29 Screwdriver. You got to use a screwdriver. That was his job. And it introduced a lifelong hatred of screw worms in his heart, you know, understandably so. But at the same time, you know, he has sort of a scientific bent of mind. He's curious. He was actually kind of fascinated by insects. Over time, he became a bugner.

Starting point is 00:06:47 Definitely a bugner. Even named his cats after insects. One after a mosquito and one after a bull weevil. Antonomous and Culex. And when he grew up, grew up to be an entomologist. But also, kind of in the back of his mind, he was always thinking, well, I have to figure out a way to control screw worm. I want to put a stop to them somehow. And as it happens, the first job I had.

Starting point is 00:07:12 In the late 30s, he got a job at the USDA. As an animalologist working on the screw worm, that was the Bureau of Entomology in Planned quarantine at that time. And then World War II breaks out. And the military enlists him in developing... Insecticides and repellence for use by the armed purpose. He actually ends up helping develop DDT. Oh, yeah. Heard of that one.

Starting point is 00:07:36 And this is actually sort of part of his journey, which is that he saw insecticides can be really effective, but they can also be really devastating from the environment. So after the war, when he gets back to his screw worm job, he's just thinking about this problem. Like, how can we figure a way to control insects that does not require spraying lots of poisons? And his way of trying to figure that out is watching screwworms mate.

Starting point is 00:08:02 Just watching a lot of insect sex. As one does? Like, yeah, why? I think he was just trying to understand these pests, right? To think, like, what could we do about it? Huh. And so one day, a colleague of nipples is, you know, watching the screwworms have their sexy times.

Starting point is 00:08:16 And he makes this observation. That sounds like maybe not that important or not that interesting. But that kind of hinted at some. something. He wasn't quite sure what exactly. Does that females only meet once? Whether or not they get pregnant, they get one shot to have intercourse and try to have eggs. I really feel for these females, like this is such a high stakes. You have to have the best sex of your life in that one time.

Starting point is 00:08:46 Yeah, that's it. But nippling, he's looking at this and he's like, wait. If you could just do something to all of the males, right? Like, if he could just make the male sterile. And then if he could trick the female screwworms into mating with these sterile males, the females aren't going to lay any eggs that are viable. That would essentially take those females out of circulation for reproduction purposes. Hmm.

Starting point is 00:09:08 Their one shot would just be doomed to fail, basically. Yes, exactly. So just, like, somehow flood the zone with sterile males is the idea. These poor females already had it so hard, and now he's just, like, ruining the dating pool for them. It's a little diabolical from the, uh, the fly. perspective. But lucky for these screw worm ladies. It wasn't like that was a very practical idea.

Starting point is 00:09:30 Because how would you even pull that off? You know, how do you mass sterilize a bunch of insects? But then he finds a paper. An article, scientific magazine. Basically since World War II, there's sort of like a lot of interest in like, what can we do with radiation? Oh, of course, right. Yeah. And this paper was by a geneticist who was saying that...

Starting point is 00:09:49 It was possible to sterilize fruit flies by a... exposure to x-rays. And I think he sort of jumped off of his couch and said, oh my God. Maybe we could sterilize through her. This could be the solution to the problem. Okay, so what, yeah, what does he do? Well, so the thing he needs is a bunch of x-ray machines.

Starting point is 00:10:15 But he decides he's not going to go public and try to get any funding for this. We knew that if the media got a hold of that, they could make quite a deal out of this. I mean, remember, he's working for the government. Like, taxpayer money is at stake here. What happens if the press gets hold of this and then we're just totally ridiculed for like...

Starting point is 00:10:35 Wishing money or something. Watching and sex sex all the time. Not in a weird way. Yeah. We were rather cautious about that. So he decides he wants to do this kind of on the down low. And basically he gets one of his colleagues... To take a bunch of screw worms

Starting point is 00:10:52 and sneak them into a nearby military hospital and use the x-ray machines there. Flash-eating worms in a hospital. Great. Yeah, exactly. But how does he get the screw worms in? Unfortunately, we don't have many details about what he did to actually get inside there. I pictured him, like, hanging out at the loading dock at night

Starting point is 00:11:11 and, like, grabbing the door right before it shuts or, you know, like watergate, like taping the lock or something like that sneaking through the hall. I believe they did this at night, too. He had to be kind of clandestine about it, sneak around a little bit. And they are literally like, you know, putting these flies through the next thing machine and be like, hey, what happens? But the problem with shooting a bunch of radiation at a bunch of flies is that you create all these mutations, a bunch of random mutations. So you might just kill the fly.

Starting point is 00:11:40 That's kind of a problem. Right. So they found that they figured out the right dose, but they also figured out exactly when to put them through radiation. It's when the flies testes are developing, right? because that's like what you really want to knock out. So that happens to be between 5.5 and 5.7 days. So it's like they've got it to within hours. Yes, yes.

Starting point is 00:12:00 And when they do that, bingo. It seems to work. But... Of course, the next thing was would they perform in a natural population? It's not enough to just do it in a lab. So then he decides it's time for a real world test, and he found an island off Florida. On the island of Sanibel.

Starting point is 00:12:19 Sanibel Island. He shows up there. with some of the radiated screwworms from his lab, releases them on the island. And it did not work. Like, the population of screwworms stayed pretty much the same. The experiment failed. And Nippling was glad he hadn't said anything

Starting point is 00:12:34 or, you know, gone after public money. So, yeah, does he just resign to his failure? That's the end of the story, yeah. No, not the end of the story. We were kind of stymied what to do for a year or so, and then I got a letter from a veterinarian on the island of Curisov. A Dutch island called Curacao.

Starting point is 00:12:54 Where is Corrissau? Off the coast of Venezuela. He wrote a letter. And said, the goats here are being ravaged. I know you study this. Can you help us in any possible way? And I thought, well, this is just a place that we're looking for. And this time, Nippling wants to go all out.

Starting point is 00:13:11 They were not going to take a chance that there would be too few flies. Like, no more handful of flies from his rinky-dink lab. They're going to set up an industrial facility for me. making these flies. And like carpet curris out. And really overwhelm them with the sterile males to make sure that they were doing everything they could to give this experiment a chance of success. So in this factory that they set up.

Starting point is 00:13:34 They came up with a formula for the food that they were going to feed them. Okay. And it was ground horse meat. That they soaked in blood and they would let they get putrid. Wow. And then they would douse it with formaldehyde. Okay. Wow.

Starting point is 00:13:50 So. Yeah. And it was cheap enough to get, you know, so they knew they could produce a lot of this stuff pretty quickly. Okay. Why the formaldehyde? I don't know why. That's such a weird. Apparently they just like the formaldehyde.

Starting point is 00:14:02 I don't know. Oh, wow. It's just a little extra kick. It's like hot sauce for them. So then from about March, 1954, they are producing 170,000 of these sterile adults per week. They are feeding them this slurry, though at this point without the formaldehyde. It took 40 tons. of the slurry to get that job done.

Starting point is 00:14:24 Wow. And it was a smashing success. The population plummeted after they started releasing these flies. His big idea had worked. Back in the United States, the livestock people especially, ranchers catch hold of this. They came to us.

Starting point is 00:14:42 And they were like, wait, we really want this. Eventually, the clamor from ranchers got so big. Nippling decided, well, I think the time is ripe. To try rolling out his group. screwworm strategy in the U.S. And so armed with some funding from the USDA. This new technique for insect control is eliminating screwworm. The first big push started in about 1957.

Starting point is 00:15:03 In Florida. And after about two years of dedicated work, they had eliminated them. Not just in Florida, but everywhere. East of the Mississippi. That is huge. And then it kind of keeps going west. The Texas cattlemen's association hears about it. I mean, it was a Texas-sized problem with that they had.

Starting point is 00:15:20 They won in two, so. Nippling and his team. He ended up building a really big factory in Texas. Screw worm eradication headquarters at Mission, Texas. Here millions of screw worm flies are being reared each day. And all these like metal machines. Sarah told us about a similar factory she went to in her reporting. Many different rooms, sort of like all at different temperatures

Starting point is 00:15:39 and different humidities for each phase of a life cycle. I could not have imagined it smelled good. I'm sorry to say this, but what it reminded me of was the smell of a used tampon. Okay. It makes sense. Well, that's kind of a little bit bad maybe. From these factories, they start releasing flies multiple times a week. So how do they do that?

Starting point is 00:15:57 By airplane. These planes are being loaded with sterile mayo screw-worm flies in Mission, Texas. Basically, they would fly these little prop planes and release these flies in the air. They took them up in refrigerated boxes. They had to buy essentially cases of perfume and cologne and dump them on the boxes before the pilots would allow them in the airplanes. And then they would essentially open the hatch and just do that. dump them out and let them fall down. Oh, wow.

Starting point is 00:16:26 And at this point, the nippling strategy is working so well. Screwworms are disappearing from all of the southwest. They started marching their way down to the border, pushing it down, pushing it down. Eventually, people were like, well, screw rooms obviously don't respect national borders. If we're really going to deal with the screw worm problem,

Starting point is 00:16:44 we would have to enlarge the program. What if we just kept going? This operation can now expand into Mexico. You know, get them out of Mexico. Then we go down country by country through Central America. That is so much ground to cover. Yep. And so all through the 70s, 80s, 90s, all these kind of international agreements.

Starting point is 00:17:04 Frankly, this was a tough sell in some places because the U.S. has a history of meddling in Central America. Right. Especially in this time. But despite that, and despite political turmoil. Revolutions and coups and things like that. Holy. The disgust over screwworms was enough that all seven countries in Central America came to the table. And they started marching down, you know, a dozen miles at a time or so, just working down

Starting point is 00:17:27 year by year, all the way down to the border between Panama and Columbia. And in 2006, all of North America is declared screw worm free. Wow. And that so-called single most original thought in the 20th century changes the face of the entire continent. Amazing. And to this day, you know, at the time I was reporting it. Like, there are still, there's still a factory in Panama. It's still producing millions of schoolrooms, growing millions of schoolworms every day, flying a plane, I think it was three times a week, and maintaining this, like, basically this, what they called of it, like a sterile insect barrier. The idea is that that area where Panama meets Colombia, the Jarian Gap, which I think it's been a lot for other reasons. That's like the most dangerous

Starting point is 00:18:17 area for migrants, right? Exactly. But it's also one of the narrowest parts of the Americas, only about 60 miles wide. Okay. It's just like a natural choke point. Right. And because of that, maintaining that sterile screw worm barrier only costs $15 million per year, which is a pretty reasonable price compared to the huge cost if screwworms were just kind of running wild. Yeah. So when I was preying on this back in 2020, the money saved was estimated to be over a billion dollars a year. So a billion dollars saved compared to $15 million cost. Wow. So that's pretty good return. And obviously it was more expensive when you were in the active eradication phase. But the maintenance costs, you know, it's really not that much money for a government program.

Starting point is 00:19:01 And it's just kind of an example of like how with basic science, you don't always know exactly where it will go. But in this case, it ended up like creating this continent-wide multinational collaboration that has been going on for decades and decades. And the fact that this all kind of started with someone like watching. screw arms meat in the lab and having an epiphany is kind of remarkable. Now, there have been a couple of small outbreaks here and there over the years, including the Florida one, the key year, 2016 one. Yeah. But they've all gotten tammed down pretty easily. Like, it didn't take all that much to beat those back. But when we come back from break, all kinds of things are going to break loose. News, biological barriers. And,

Starting point is 00:19:51 and maybe also Lathif's heart. This is Radio Lab. I'm Lathif Nasser here with producer Sarah Kari. Hello. And we've been talking to journalist Sarah Zang and writer Sam Keen about screwworms. Right. The skin-crawly, flesh-eating parasite that we all forgot about because nippling and hysterol flies drove it down south.

Starting point is 00:20:23 All the way to a biological demilitarized zone at the very bottom of North America, aka the southern border of Panama. Yeah. But in 2023... Panama suddenly started seeing a massive spike in screw worm cases from like 25 cases a year to like thousands.

Starting point is 00:20:47 And since then... It's only gotten worse. The parasitic fly is moving north. They have been steadily marching north. They've been found in Kirstrikes of this deadly insect. They've been found in Kastri. Nicaragua, Honduras, El Salvador, Guatemala. Even in Mexico.

Starting point is 00:21:03 Only 700 miles from the U.S. border. And it turns out it's basically getting closer every day. Less than 400 miles. 300 miles from Texas on the southern border. It's gotten as close as 70 miles or so from the U.S. border. Whoa. This is an ongoing breaking news story. So what happened?

Starting point is 00:21:22 Like, how did they get past the biological wall? There are a couple of theories. One theory is that. maybe the strain of scurrum that they were growing at the factory is not as effective anymore. I don't know, maybe the ladies out there caught onto what was going on and weren't mating with them or something. Just general disruptions due to COVID might have weakened the production a little bit. Or maybe, Sam says, given that we live in a more and more interconnected world.

Starting point is 00:21:47 Because it does still exist in South America. Where people and products and animals are moving from place to place, it was just a matter of time before these worms found their way through. The best guess is that people were smuggling cattle that were infected, and then it just got out. But regardless, as of today, right now, the screw worm, it's sort of like knocking on our doorsteps. It's not a matter of if the deadly pest gets to the U.S. but when. And surprisingly enough, in this time of cuts to science funding and all that and, you know, the idea of building political will around something that everyone has pretty much forgotten seems dubious. The issue has also alarmed Washington.

Starting point is 00:22:27 It actually does seem like the U.S. government is paying attention. The U.S. Department of Agriculture has snapped into action. And really, just like Nipling's time, pretty much because of the cattle industry. Billions of dollars of losses a year. Of course. It could truly crush the cattle industry as well as other livestock industry in Texas. So the USDA has started to set up screw worm traps along the U.S.-Mexico border. Cut down the southern border.

Starting point is 00:22:56 They have agents on. horseback. Some so-called tick riders. Patrolling the border for stray cows. They are pouring money into screw worm research. And of course, they are rebuilding nipplings fly factories. They are now building a new facility down in Texas. Another one in Mexico.

Starting point is 00:23:14 All told, probably in the next couple years, we will be producing and releasing something like 500 million flies per week. Wow. And we probably will have spent like 100. hundreds and hundreds of millions of dollars. Do you see this as like the modern cow factory farm system is like unsustainable? And like this is just like one other band-aid to keep that system financially profitable or something. Like I could see an argument that's like, oh, this is just to help like big rancher businesses.

Starting point is 00:23:48 Yeah. Well, I think in a literal sense, like this program was created to help ranchers. That is in fact the express purpose of the USDA. So I think I wouldn't even argue with that premise. But this does affect wild animals too. Right. In Central America, like, used to see, like, howl or monkeys fall out of trees because they had become so disfigured and sick from getting infested by schoolworms.

Starting point is 00:24:11 And beyond that, I mean, actually, you know, this time around with this effort, it's not just the USDA that's involved in this program. So I'll try and make the case on the human side of things. Number one. So I talked to this public health official named Megan. Nichols, who is at the CDC. And my current role is incident manager for our New World Screw Worm Response. Because the CDC is worried about this outbreak too. And the thing that Megan pointed out is that these flies like to infest a wound. I mean, you know, wildlife or cows aside,

Starting point is 00:24:47 screwworms will happily lay their eggs in pretty much any warm-blooded animal, including humans. And it can be a pretty small wound, like as small as a small as a little. little cut or a bite on the skin. I read that they can also get in through just like bodily openings. Is that true? It is true. They are often attracted to mucus membranes, so eyes, nose, ears, yourogenital. Yikes.

Starting point is 00:25:16 So yes. And during this outbreak, there have been over 1,000 human cases and the number continues to grow daily. And to be fair, you know, like not to fearmonger here. This is not a pandemic-level human health crisis. Most people that take precautions will be totally fine. But I also think very much about this on an individual level. And the kinds of individuals that would be the most susceptible to a serious screw-worm infestation,

Starting point is 00:25:42 like folks who can't get medical help right away, or people who are unhoused, or have weakened immune systems, or even, like, kids with a lot of scrapes. They're the last ones that need to deal with something like this. And on the off chance that it does happen, it is kind of a horror show. One of the most impactful images that I have seen related to 2025 was patients that were lining the hallway of a medical treatment facility in a country that is currently part of this outbreak. And the patient was holding a bowl in which they were basically sneezing out and pushing out larvae from their nasal passage. and other people who were lining this hallway basically waiting to be seen

Starting point is 00:26:27 because they were also needing to get the maggots out of their body. Oh my gosh. Okay, all right. I now see the point that this is more than just the cattle industry. But I do now wonder if it's just going to keep coming back. Like, is this just an inevitable cycle that we're now stuck? in, like, we're just going to have to keep doing this. Yeah, you kind of are on a treadmill.

Starting point is 00:26:59 You're on a treadmill. Using nippling's technique, yeah. Yeah. But I did, as I was reporting on this, come across a different way that people are starting to think about screw worm control. So another option that is controversial, but scientists have been talking about it. This is something that Sam mentioned, too. It's something called a gene drive.

Starting point is 00:27:19 Okay, so what is that? It kind of goes around the normal Mendelian laws of genetics. Okay, so first of all, let's assume that you are a scientist that has modern day genetic technologies available to you, and you introduce a killing gene into the screw worm population. You could make it lethal to be a female, so it could trigger something where females just don't get out of the egg stage. It's like a little time bomb in the cell. Yeah, exactly. And typically, if you were to try to do that, genetics would work its normal way,

Starting point is 00:27:51 and that killing gene would only get inherited 50% of the time. And in every successive generation, it would become less and less common. And you'd have to keep reseeding that gene into the population. Okay. But this is where gene drives have a little extra trick. In a gene drive, there's closer to 100% chance that the gene will get passed down. You can basically ensure that it'll get passed down every time. And so it's kind of like a set it and forget it kind of thing.

Starting point is 00:28:21 thing. Like, you introduce the killing gene and then you just let it have its way with the screw worm population. The screwworm is going to be out there reproducing and spreading that gene by themselves very quickly. And what that really means is eventually it's going to wipe them out. Not just, you know, beating screwworms back down to Panama, but like truly and wholly eradicating screwworms. Extincting them off the face of the planet forever. I just, well, like, I, I don't want us to have to live with these, but I don't want us to kill them forever. That feels wrong. That feels like we're doing something untakebackable that is not, that we should not be doing. Yeah.

Starting point is 00:29:06 Yeah. So, I mean, but let me bring in one more person here. So I'm Greg Kavnik. I am a research scholar and the Hastings Center. Because I think he feels a lot of the same way. I mean, here we are in the early stages of the sixth major extinction, one that we humans are causing. And, I mean, in a way, this seems like, gosh, joining forces with the other side in some way. Yes, yes, exactly. Well, but at the same time, Gregory has seen this potential use of gene drives coming on the horizon and really wanted to think about it more. So what he decided to do is get together a panel.

Starting point is 00:29:47 I thought, and I'll turn to some environmental ethicists, ecologists, conservation biologists, geneticists, entomologists, some people with public health background. No one from the Texas cattle ranchers association. We already know what they think. I thought it would be particularly interesting to bring together people who would be, by and large, kind of predisposed to want not to take out species. So?

Starting point is 00:30:11 We gathered at Arizona State. In May 2024. for a day and a half of presentations and discussion. They considered a couple of the top nasty species. Like the mosquito species that is the main vector of malaria. And one of them was screwworms. Yes. So the idea was to hash out some of the pros and cons for either side.

Starting point is 00:30:34 You know, keep, eliminate, and sort of report out our findings. And given the group of people that were sitting at the table, they started out with some of the arguments that you might expect. We need to think about the value of species. Yeah, what do you mean when you say that? Yeah, I mean, there'd be different ways in which a species could be valuable. Like, first off, there's some very practical ecological considerations. I mean, the main question is, what's it doing in the wild? You know, is it a pollinator?

Starting point is 00:31:05 Turns out, screw worm is something of a pollinator. Is it? Yeah, it is. Oh, my gosh. Yeah. but it's probably not a very important pollinator. Okay. Bees do it better?

Starting point is 00:31:18 Yeah, the bees probably win. Then you have to consider whether some other animal needs to eat it. Probably sometimes. But it turns out it's not really a key food source for any other animal. Is it, does it play an important role as a predator in keeping other species in check? I mean, obviously in this case, yes, it is a predator. But according to Gregory, the animals it eats are already under pressure. from human forces.

Starting point is 00:31:44 So if anything, you want to ease the burden as much as you can on those species. Okay, but they did also consider some more abstract values that a species might have. You know, aesthetic. Esthetic. Educational, historical, scientific. I think that's the list. Or maybe we put it in terms of screw-worm. Yeah.

Starting point is 00:32:06 In my mind, I was thinking about it, like, if you were going around the way you did and you opened it up to all your colleagues, and then sitting there was a giant screw worm who was going to make the case to save itself. Yeah, like, what's the best case that that screw worm would make? That's the hard case. Aesthetic, clearly, obviously. Educational, like, don't mess with nature kids.

Starting point is 00:32:40 You know, jokes aside, though, Gregory says, you know, people like him do actually put a lot of stock in this sort of intrinsic value of a species. It's this ingenious development in and of its own right. You know, anything that's around today has been honed by millennia of evolution. And in that way, every species is a marker of the creative, natural forces that sustain life that brought us into being. I mean, I feel like you have to try to put it in a practically poetic way. in order to really convey what people are thinking. So Gregory's group, after about a day and a half,

Starting point is 00:33:17 of discussing all of this... We're all kind of exhausted and we're trying to, like, put it all together. And Gregory says, okay, we're going to go around the room one by one. Sort of put everyone on the spot and see what they thought. And we did so. And by the time we'd gone around, And everyone had, most people had, I think maybe everyone had actually said, yeah, screw worm looks like a pretty good candidate.

Starting point is 00:33:50 Really? Like that it would be okay to wipe this species off the planet forever? Yeah. How did that feel? Is that awkward? Well, I mean, it was just like, it was kind of like this serious moment that was. Everyone was sort of sighing. Or it's like, oh, I really don't want to, I really don't want to vote for this, but, but it looks like maybe the case can sometimes be strong enough.

Starting point is 00:34:22 But isn't there sort of like, I mean, this just feels like, you know, an idea that always comes up with ecosystems. Like, we think we know and then we don't. Like, there's always the knock on effects that we never see coming and we thought we knew everything, but then it surprises us. But there it is. Like, does it not feel like hubris to assume that we know everything that could potentially go wrong? Yeah. But we did, in fact, at least up until very recently, get rid of screw worm in southern North America and throughout Central America. And, you know, the sky didn't fall.

Starting point is 00:34:57 Other species didn't wink out because they weren't able to eat New World screw worm anymore. So we have a little bit of a kind of preliminary. Like experimental data. Yeah, kind of. That suggests that it's probably not really that important ecologically. So losing it, you know, doesn't seem to do any harm. And then on the other side, part of what was so persuasive about it was that the death that it causes is exquisitely awful.

Starting point is 00:35:29 I mean, with screwworms, did you guys consider alternatives to eradication? Like if there were some other kind of treatment for it, some sort of medicine, that you could take. Gregory says if it was possible to like separate screwworms from the thing that they do or like the disease that they cause of, you know, flesh being eaten and you, if you could attack that disease, then, then great, you know, like that's sort of the case with malaria and mosquitoes where you can you can attack the disease or in that case, the parasite, rather than the mosquito. But with screw worms, there's just no way to do that.

Starting point is 00:36:05 Like eating flesh is in their nature. It's what they do. There's just no way to make them like vegetarians or make them uninterested in flesh. The only way you get rid of the disease is by getting rid of the fly. At least at the time that we were meeting in writing, there was nothing else to do except pick it out if you can. Eliminate the flies. I don't know. I don't know.

Starting point is 00:36:49 I want to agree with him, but I just don't know if that wins the day for me. Like I'm I don't disagree, but I just can't bring myself to agree. No, this is, you know, this is the part of the story where I feel like I agree with you. I don't know. I don't know what to do with the fact that I don't want screw worms to exist. You know, like I think about like the people in South America. We just stopped at Panama. Like, I don't know.

Starting point is 00:37:16 I don't want them to have to deal with screw worms and suffer. But at the same time, this stuff gets scary. I guess one thing I will say, though, that Gregory did mention is that if we go down this path, theoretically, there is sort of an undo button here. You can definitely keep it somewhere else in a facility or frozen eggs or something. And if it were to turn out that... Like the cure for cancer was in the screwworm eggs or... It's really vital to the life cycle of this frog species in South America or something like that.

Starting point is 00:37:59 Some ecological Bruke Goldberg machine got set off because we got rid of all the screwworms. Yeah. It would be possible to achieve something like de-extinction with screwworm. To bring it back to seed it, flinging out of the planes the way we're flinging out the sterile ones. Yeah. And what we know from the outbreak in Central America now is, that they can take off pretty well. Imagine the, like, public campaign

Starting point is 00:38:31 where it would be like, hey, everybody, remember how we... Remember how they used to exist. There's this one frog in Panama that this was really helpful for, so we're just going to drop these flesh-eating worms. We're just going to rain them down over you and your home. Yeah. So one last thing, before we go,

Starting point is 00:38:58 Back in 2016, Edward Nippling and his screwworm research won a Golden Goose Award. If you haven't heard of it before, the Golden Goose Award goes to U.S. government-funded science that sounds ridiculous but ends up changing the world. And Nippling's research was exactly that. Even years after it proved useful, members of Congress still ridiculed and scapegoated it. Frivolous pork projects such as the screwworm research, $35 million. As an example of government waste. even though the screw worm has been eradicated in the United States. This is now the fourth golden goose-inspired story that we have done.

Starting point is 00:39:34 Nice. We did one about cone snails called Golden Goose, one about a bacterium called the Age of Aquaticus, and one recently about honeybees called Time is Honey. And now this one, it's almost become like a sneaky little recurring series that if you ever meet someone who doesn't believe that the government should fund basic science, just play them one of these. We'll link them all in the episode description. This episode was reported and produced by me, Sarah Kari, with reporting help from Lathafnasser. Our fact checker was Emily Krieger.

Starting point is 00:40:05 Check out Sam Keen's podcast, The Disappearing Spoon. His episode about screwworms is linked in our episode description. Same goes for Sarah Zang's latest story in the Atlantic. And if you were interested in hearing more about Gene Drives, check out our episode about it, the last 10 minutes of our CRISPR update. Thank you, too. James P. Collins, Max Scott, Amy Murillo, Daniel Griffin, Phil Kaufman, Katie Barnhill, Arthur Kaplan, Ron Sandler, Yasha Rower, and our gaggle of friends at AAAS who administer the Golden Goose Award, Aaron Heath, Gwendolyn Bogart, Valeria Sabate, Meredith Asbury, and Joanne Padron Carney. And the last, last thing, if you want more information on screwworm-infested areas or how you can take precautions to be safe, there is a website you can check out. It is screwworm.gov. That's screwworm.gov.

Starting point is 00:40:56 Sorry, I guess it's time for us to just screw off. Indeed. And we'll catch you next week. All right. Hi, I'm Gabby. I'm from San Francisco, and here are the staff credits. Radio Lab is hosted by Lula Miller and Lettif Nasser. Sorin Wheeler is our executive editor.

Starting point is 00:41:28 Sarah Sandbach is our executive director. Our managing editor is Pat Walters. Dylan Keefe is our director of sound design. Our staff includes Jeremy Bloom, W. Harry Fortuna, David Gable, Maria Paz Gutierrez, Sindu, Nainasembandan, Matt Kielty, Mona McGawker, Annie McEwen, Alex Nason, Sarah Kari, Rebecca Rand, Anisa Vizza, Arienne Wack, Molly Webster, and Jessica Young. With help from Gabby Santis. Our fact checkers are Diane Kelly, Emily Krieger, Natalie Middleton, Angela Mercado, and Sophie Semayee. Leadership support for Radio Lab's science programming is provided by the Simons Foundation and the John Templeton Foundation. Foundational support for Radio Lab was provided by the Alfred P. Sloan Foundation.

Radiolab - Return of the Flesh-Eaters

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