Should we reengineer the world's deadliest animal?

The most ferocious predator for us humans is actually quite small: the mosquito. They are hungry for blood, spreading diseases like malaria, yellow fever and dengue – and picking up new ones all the time. But what if we could wipe out the mosquito? Gene-editing technology could do it, potentially saving millions of lives. But it comes with serious potential for risk. Which begs the question: Should we get to decide when humanity rewrites nature? Here to discuss that is Ben Bradford https://www.linkedin.com/in/jbenbradford/, the host of a new podcast distributed by the NPR Network: Are We Doomed? https://www.npr.org/2026/04/21/g-s1-118208/a-new-npr-network-podcast-asks-the-big-question-are-we-doomed Interested in more science? Email us your question at [email protected] mailto:[email protected]. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave http://plus.npr.org/shortwave. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Speaker 00

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• 0:15Emily Kwong?

  You're listening to Short Wave from NPR.

• 0:21Emily Kwong?

  The most ferocious predator for us humans is actually quite small. It's the mosquito. They are hungry for blood and spreading diseases all the time, including serious ones like malaria, yellow fever, and dengue. But what if we could wipe out the mosquito? We have the technology to do it, but should we? Here to discuss that is Ben Bradford, the host of a new podcast distributed by the NPR network. It's called Are We Doomed?

• 0:48Speaker 02

  It is. Hi, Emily.

• 0:50Emily Kwong?

  So Ben, your podcast, Are We Doomed, covers a lot, from killer AI to nuclear weapons and, of course, the bloodthirsty micropredators I want to talk about today. How do you feel about mosquitoes, by the way?

• 1:00Speaker 02

  I think they're gross and I think they're rude. And you mentioned, Emily, new gene editing techniques could allow us to eradicate our little insect nemesis, potentially saving millions of lives.

• 1:10Emily Kwong?

  Yes, I learned that from you, from your show.

• 1:12Speaker 02

  Yeah, thank you.

• 1:12Emily Kwong?

  The tech is here.

• 1:13Speaker 02

  Yeah, thank you. And it would be amazing. But also, in that technology is something inherently more dangerous. I talked to Kevin Esvelt, who is a biologist now at the MIT Media Lab.

• 1:25Speaker 03

  If you can engineer a mosquito so it can't spread disease, you could engineer a mosquito so it always spreads disease.

• 1:33Emily Kwong?

  Today on the show, the technology that allows us to kill the mosquito comes with all kinds of complications.

• 1:38Speaker 02

  So what does it mean to try to change an entire species? Who gets to decide what might the ripple effects be? How do you test it? How do you protect it?

• 1:46Emily Kwong?

  Easy questions, you know? You're listening to Short Wave, the science podcast from NPR.

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• 3:09Speaker 06

  Oh, Kevin, it feels good to be back. It sure does, Casey. And what a time. The world is talking about AI and what's going on in Silicon Valley. And we are here with a new show to tell you all about it. That's right, Kevin. On our new show, Machine Gods, twice a week, we'll be bringing you the biggest news in tech and bring you unmatched access to the real titans of this industry. You can find Machine Gods from NPR on the NPR app or wherever you get your podcasts.

• 3:33Emily Kwong?

  OK, sure, I'm here with Ben Bradford, who's just done all this reporting on how to save millions of people from malaria by wiping out the mosquito. Ben, how does that even work?

• 3:45Speaker 02

  Yeah. So let's go back to early last decade. Scientists developed a new form of gene editing, which you may know as CRISPR.

• 3:53Emily Kwong?

  Mm hmm.

• 3:53Speaker 02

  It's this way of scalping out a tiny strand of DNA and you kind of like suture in a new trait. It doesn't quite look like that, but that's essentially what's happening.

• 4:01Emily Kwong?

  Yeah.

• 4:02Speaker 02

  And so with CRISPR, you can cure a genetic disease or engineer a cow to grow without horns, both things that they have done in labs.

• 4:10Emily Kwong?

  Wow.

• 4:10Speaker 02

  But. Kevin Esvelt, this biologist now at the MIT Media Lab, had his own realization.

• 4:16Speaker 03

  Turns out it doesn't just let you engineer organisms in the lab. It lets you let them go and the engineered trait will spread to most of the ones in the wild. That's incredibly exciting.

• 4:26Speaker 02

  Kevin is the person who figured out you could CRISPR creature, do his little DNA surgery. So it always passes along the gene that you put into it. And so with CRISPR, the idea is you can create a mosquito that, for instance, always has males. And then its offspring will always have males. And so you put it into an area and it extinguishes all these species carrying malaria in that area.

• 4:50Emily Kwong?

  Because there are females to mate with. Yeah.

• 4:51Speaker 02

  Yeah. And so to do this, you of course have to engineer a mosquito from hell. In the show, we called him Jerry.

• 5:00Emily Kwong?

  Hi.

• 5:03Speaker 02

  To clarify, Jerry's mission is actually not to murder all mosquitoes because they're just trying to target in an area with malaria. And that's because mosquitoes are ecologically important.

• 5:13Emily Kwong?

  They are important to the environment.

• 5:15Speaker 02

  I didn't know that, but they are. And it was disappointing. They're pollinators and birds and spiders. Yeah, all kinds of critters eat them.

• 5:22Emily Kwong?

  Yeah, it would be reckless to wipe out mosquitoes entirely. But when it comes to Jerry, the mosquito from hell, he's just meant to wipe out the mosquitoes that carry malaria in a certain region. But then the question becomes, how do you do that without affecting birds and spiders?

• 5:37Speaker 02

  So the idea is to offer birds and spiders a different kind of mosquito to snack on, one that doesn't transmit malaria, because there's a whole bunch of different types of mosquito species. And even better or worse, Kevin says, we don't need to take out the malaria carrying mosquitoes forever even.

• 5:54Emily Kwong?

  Right. You say in the show, they just need to, quote, "go on a sabbatical."

• 5:58Speaker 02

  Yeah, that's right. We just need them to disappear for a little while.

• 6:01Speaker 03

  Malaria transmission requires humans and it requires mosquitoes. So this is a back and forth transmission chain.

• 6:07Speaker 02

  So if the mosquitoes go on sabbatical for long enough, for the malaria to die out in the humans that the mosquitoes pick up the malaria from and transmit between, then when the mosquitoes come back, the malaria is gone and there's just nothing for them to transmit.

• 6:21Emily Kwong?

  This plan is bold. Uh, it's like, use CRISPR, make mosquito. Mosquito Jerry, though, only makes suns. And then the malaria mosquitoes will be wiped out, but not for too long because that would be bad.

• 6:33Speaker 02

  Just enough.

• 6:34Emily Kwong?

  Just a sabbatical.

• 6:35Speaker 02

  Yeah, and so it turns out that there's a whole bunch of steps that you kind of have to follow if you're going to do this in a way where you, one, test that the thing actually is going to work, and, two, test that it's not going to work too well and go around the world and create a whole bunch of problems.

• 6:47Emily Kwong?

  So how do you even go about testing this?

• 6:49Speaker 02

  Well, you need an area where you're going to put out your mosquitoes into the wild, kind of a cordoned off area where they're going to be on their own. And basically, what we're describing is a mosquito Jurassic Park. And then that leads to other questions, which is, how do you stop what happens in every Jurassic Park movie?

• 7:04Emily Kwong?

  Uh, the dinosaurs get out.

• 7:05Speaker 02

  And so, of course, this is the challenge, and we know what we're trying to avoid because we've seen it in history.

• 7:10Emily Kwong?

  Let's listen to a section of the episode that talks about how this can all go wrong.

• 7:17Speaker 02

  Take a tangent with me to the shores of Australia and New Zealand in the late 1800s. European ships landed, bringing sailors and soldiers and felons and rabbits. Europeans brought rabbits over for food and hunting, snacks and sport. Of course, the rabbits quickly escaped and bred all over both islands and became a scourge on an environment totally unprepared for them. They eat everything. New Zealanders looked to fight back. They brought over ferrets and weasels to sic on the rabbits. And when that failed, ferrets and weasels became more invasive species. Skip to the 1990s. Neighboring Australia, largely by accident, unleashed an only partially tested biological

• 8:02Speaker 02

  weapon against its rabbits.

• 8:04Speaker 03

  This nasty virus that wipes out like 2/3 of all rabbits or more.

• 8:09Speaker 02

  New Zealand had been considering using this virus as well, but it wanted more testing first.

• 8:14Speaker 03

  New Zealand government said, "We're not sure of safety and so forth, so for now, you're forbidden to import this virus into New Zealand."

• 8:21Speaker 02

  So what do you think happened at this point? New Zealand farmers, losing millions of dollars as rabbits destroyed their crops, began taking little vacations to Australia to go hunting for infected rabbits.

• 8:34Speaker 03

  And they smuggled in diced up infected rabbit parts from Australia illegally.

• 8:41Speaker 02

  They liquefied the body parts into virus-laden smoothies, which they spread on their fields. Bam, New Zealand had the rabbit virus.

• 8:50Speaker 03

  And what's the government gonna do? When it's out, it's out.

• 8:53Speaker 02

  This is Kevin's fear. If we do create a mosquito Jurassic Park to test Jerry, which we have to do to make sure he works and doesn't cause a ripple effect of unknown ecological destruction, Kevin says some New Zealand farmer's gonna steal one of our mosquitoes.

• 9:07Speaker 03

  Of course, someone would do that. And they would tell themselves a perfect story in which they're the hero, right?

• 9:11Speaker 02

  If Jerry gets out, we don't know what harm he would cause because we haven't field tested. Consider the possibilities. Jerry and his descendants could travel around the world. These mosquitoes would spawn only males wherever they go, leading to globally extinguishing all of his species. Worse, what if it turns out Jerry can mate with another type of mosquito? And he passes along his all-boys gene to one of them? What if that one can mate with another species and so on? Maybe that gene travels throughout all types of mosquito and does eradicate them entirely. What if birds and spiders and flowers can't adapt to that loss? And it creates a domino effect of environmental destruction?

• 9:55Speaker 02

  Then we've got a problem.

• 10:03Emily Kwong?

  This approach, you know,

• 10:05Speaker 02

  Yeah.

• 10:05Emily Kwong?

  clearly comes with so many unintended consequences. You say on the show, the point is to insert a trait that spreads like wildfire, and wildfire is hard to stop.

• 10:15Speaker 02

  Yeah, and so that is the main argument against doing this thing, this technology, which is basically called an engineered gene drive. And so there are people who think we should, you know, pack this up, seal it away, never do it.

• 10:29Emily Kwong?

  And a gene drive in nature is when like a trait kind of naturally evolves to get passed on.

• 10:34Speaker 02

  It gets really good at being passed through its offspring.

• 10:37Emily Kwong?

  But here, humans are interfering to make that happen.

• 10:39Speaker 02

  Here, we're making it happen.

• 10:40Emily Kwong?

  Yeah.

• 10:40Speaker 02

  Yeah, that's sort of the debate. But of course, the stakes are... Do you get rid of malaria? Do you get rid of dengue fever? And so when I talked to Kevin, the person who kind of figured out, hey, we could do this. His biggest concern is that an accidental, untested release of, let's say, Jerry, poisons the whole discourse around this in any attempt to do it.

• 11:05Speaker 03

  We know what happens when there's a backlash to technology. We're seeing it right now for vaccines and other things. And we saw it even in biomedicine with something like gene therapy, where a single death in a poorly planned clinical trial that led to tragedy, set back the entire field by more than a decade. More than a decade is more than 5 million dead children.

• 11:24Emily Kwong?

  That's a lot of pressure because, you know, mosquito borne diseases cost the lives of hundreds of thousands of people every year. But on the other hand, you don't want to roll out a gene drive project too quickly because something could go terribly wrong.

• 11:37Speaker 02

  And you can hear in our episode that pressure that Kevin feels because of that. And so it does, it creates all of these hurdles, all of these kind of like little puzzles that you need to solve to be able to do that. You know, we need to test our mosquitoes like Jerry to make sure he doesn't cause unintended consequences. You have to do this sort of like field test, your Jurassic Park. But how do you do the Jurassic Park without risking those consequences? Where someone's going to steal them or he's going to get out? I mean, they fly for God's sakes. So like, what are you going to do?

• 12:04Emily Kwong?

  It is such a puzzle. And in your episode, you talk about some ways to work the puzzle, to actually like take what's theoretical and make it happen in the real world.

• 12:14Speaker 02

  These guys are so smart. They're so smart.

• 12:16Emily Kwong?

  What is your takeaway from all of this? When it comes to the ethics of a gene drive for mosquitoes, but really also for any species?

• 12:23Speaker 02

  Yeah, I think that the possibilities here are really exciting. I mean, malaria is terrible and the mosquito has killed more people than any other creature on the earth. And so you start thinking about how we can solve that for our species. That's amazing. But, you know, I will say, you know, one of someone else on our team, our animator, who was watching this episode and doing our animation for it. And he heard it and was like, this is insane. We should never do this.

• 12:52Emily Kwong?

  Ben Bradford, your podcast, Are We Doomed, is out now. Thank you so much for coming into Shorewave.

• 12:57Speaker 02

  Thank you for having me.

• 13:00Emily Kwong?

  Check out the show. It's really good. You can find it all the places you typically get your podcasts. And also, if you haven't already, download the NPR app. My bosses really want you to do it, and you will honestly get great journalism from it. Thank you. This episode was produced by Rachel Carlson and edited by our showrunner, Rebecca Ramirez. Tyler Jones checked the facts. Kwesi Lee was the audio engineer. I'm Emily Kwong. Thank you for listening to Short Wave from NPR.

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