A Quarter Of All Known Animals Are Beetles : Short Wave NPR science correspondent Nell Greenfieldboyce had to know more when she recently heard this mind-bending fact for the first time: a quarter of all known animal species are beetles.

Turns out — it's not just that beetles are incredibly diverse. It's that they inspire a lot of passionate study within the scientific community. But there's at least one other animal that might give beetles a run for their money.

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This Is Not A Typo: One In Four Animals Known To Science Is A Beetle

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This Is Not A Typo: One In Four Animals Known To Science Is A Beetle

This Is Not A Typo: One In Four Animals Known To Science Is A Beetle

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  • <iframe src="https://www.npr.org/player/embed/910447004/911213747" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

MADDIE SOFIA, HOST:

You're listening to SHORT WAVE from NPR.

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SOFIA: Maddie Sofia here with NPR science correspondent Nell Greenfieldboyce. Nell?

NELL GREENFIELDBOYCE, BYLINE: Maddie?

SOFIA: Let's just start off with this wild fact - that beetles are a quarter of all animal species. Beetles.

GREENFIELDBOYCE: OK, that's all known animals, all known animal species. And this is a key, key distinction.

SOFIA: Fine. Fine.

GREENFIELDBOYCE: Now, there's this famous biologist named J. B. S. Haldane. And he was once asked what science had revealed about God. And he said that the creator apparently had a, quote, "inordinate fondness for beetles." That is a famous quote.

SOFIA: (Laughter).

GREENFIELDBOYCE: And, you know, he just noted that there are so many different kinds of beetles. I mean, it's staggering. There's around 400,000 known species. And that's, you know, as you said, a quarter of all known animals. And new ones are being discovered all the time.

SOFIA: I mean, how are more people not talking about this, Nell? Like, why did I have to turn 30 to learn this fact?

GREENFIELDBOYCE: I've been reporting on science for a long time. And this one hit me, too. And...

SOFIA: (Laughter).

GREENFIELDBOYCE: ...I don't know what to tell you. I just, you know, I came across this fact. And I was kind of staggered by it. And my initial reaction was, let me understand why it is that beetles are so uniquely diverse. And then I realized, oh, this story actually is a little different than I thought.

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SOFIA: (Laughter). So today on the show, the amazing biodiversity of beetles and the other animal giving beetles a run for their money for the title of most-diverse critter. You're listening to SHORT WAVE, a daily science podcast about beetles from NPR.

Did that smooth - did anybody notice this show just became about beetles?

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GREENFIELDBOYCE: Part 1...

SOFIA: (Laughter).

GREENFIELDBOYCE: ...Of our 400,000-part series. Get ready for more beetles programming.

SOFIA: (Laughter) Oh, my God.

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SOFIA: OK, Nell, beetles - tell me everything. We have 13 minutes.

GREENFIELDBOYCE: All right. Well, you think you know what a beetle is, and you basically do. You've seen them.

SOFIA: (Laughter).

GREENFIELDBOYCE: It's just an insect with a hard-wing case. And, you know, there's all kinds. As we've noted, there's ladybugs and scarabs, you know, those Egyptian ones. There's stag beetles with their, you know, big jaw-like things and...

SOFIA: I love those.

GREENFIELDBOYCE: ...Jewel beetles that are really pretty...

SOFIA: Oh, they're beautiful.

GREENFIELDBOYCE: ...And colorful. There's Whirligig beetles. I mean, you could just go on and on and on and on. Don't even get me started on weevils...

SOFIA: (Laughter).

GREENFIELDBOYCE: ...The beetles known as weevils.

SOFIA: Don't even get me started on weevils.

GREENFIELDBOYCE: The sheer number of species out there is staggering. And it's part of the fascination, you know, for at least one scientist I talked with, Rachel Smith.

RACHEL SMITH: It's kind of akin to, like, early humans looking up into the sky and, like, gazing at this, like, vast unknown. But we have this vast unknown here on Earth with, like, this crazy diversity of beetles that seemingly never ends.

SOFIA: Yeah. I mean, Nell, beetles are the new stars. That's what I'm always saying.

GREENFIELDBOYCE: Actually, that famous quote that we mentioned from that scientist who said God has an inordinate fondness for beetles, he actually said for beetles and stars, so...

SOFIA: (Laughter). So I reiterate what I said, yeah.

GREENFIELDBOYCE: So, you know, that person I spoke with - Rachel Smith - she's actually a college student. And she's about to graduate from the University of Kansas. And she recently had this research job on campus. And as part of that, she was handed a bunch of water beetles that had been collected in South America. And she was told, look, basically sort through them. See if there's any new species there.

SOFIA: That feels like an undergrad-student project if I've ever heard one, Nell.

SMITH: I had about 2,000 specimens that I sorted through and came up with these 18 new species.

SOFIA: (Gasps).

GREENFIELDBOYCE: Eighteen new species - all brown, oval shaped, and they were very, very small.

SMITH: The average size of these beetles is probably about the size of a capital O in size-12 font.

GREENFIELDBOYCE: So that's teeny tiny. And to tell the difference between teeny tiny brown beetles like this, you need a microscope.

SMITH: And really, it came down to - this is going to sound funny. But it came down to the morphology of the male genitalia.

SOFIA: OK. Wait, Nell. So you find a beetle with slightly different genitalia and boom? Like, that's all it takes? You've got a new species. I feel like team beetles are cooking the books a little bit here, Nell.

GREENFIELDBOYCE: Well, there's genetic differences, too, OK? It wasn't just the genitalia.

SOFIA: OK.

GREENFIELDBOYCE: But, I mean, you're right. We could get into a whole different conversation about what it means to be a species...

SOFIA: Yeah.

GREENFIELDBOYCE: ...And what counts as a new species. I mean, as a nonscientist, I've got to tell you. To me, it just seems like you declare a new species and say, come on, fight me. You know what I mean?

SOFIA: (Laughter).

GREENFIELDBOYCE: There's not a clear definition.

SOFIA: Right.

GREENFIELDBOYCE: But, you know, it takes a lot of devotion to patiently examine the genitalia of tiny microscopic brown beetles. And beetles have traditionally inspired that kind of dedication. Charles Darwin loved beetles. And he was not the only one. One of Napoleon's generals had one of the largest beetle collections in the world.

ANDREW FORBES: Collecting beetles was a hobby in the 1800s. People would go out and collect as many beetles as they could and then, you know, get together and compare the size of their beetle collections.

SOFIA: I mean, I don't know why these beetle parties have to stop, Nell. You know what I mean? Like, we've got two of us right here.

GREENFIELDBOYCE: You know, I don't feel that I need to compensate for anything...

SOFIA: (Laughter).

GREENFIELDBOYCE: ...With the largeness of my beetle collection.

SOFIA: (Laughter). Fine, fine, fine.

GREENFIELDBOYCE: Anyway, that was Andrew Forbes. He's an evolutionary biologist at the University of Iowa. And he says, OK, look...

FORBES: It's certainly true that there are more species of described beetles than any other kind of animal.

GREENFIELDBOYCE: But maybe that's because beetles tend to be relatively easy to find. And, you know, they're also hugely charismatic.

SOFIA: And you mean, like, scientifically charismatic. Like, they have distinguishing physical features, not necessarily like, oh, people are really drawn to that beetle at parties. There's just something about that beetle.

GREENFIELDBOYCE: I mean, charismatic from a scientific viewpoint, OK? But people do think they're beautiful. I mean...

SOFIA: Yeah.

GREENFIELDBOYCE: ...They're certainly more traditionally charismatic than the insect Forbes likes to study. And that would be parasitic wasps.

FORBES: These are these tiny little wasps that lay their eggs in other insects.

GREENFIELDBOYCE: He says the larva consumes the host.

FORBES: Eventually, it will kill the host. And it bursts from the host's body kind of like Ridley Scott's "Alien," you know, like, this horrible thing.

SOFIA: Yeah, I actually am a big fan of parasitic wasps. We've talked about them on the show before - very different critter than your common backyard wasp, to say the least. So we're talking about wasps now, Nell, because they might be as diverse as beetles. Is that what's happening?

GREENFIELDBOYCE: Well, that is the question. I mean, Forbes says these wasps are incredibly diverse with around 100,000 known species. But there are way more unknown species. In fact, Forbes and some colleagues recently looked at different insects and the wasps that parasitize them to kind of come up with an estimate of, like, how many wasp species you would be expected to have out there?

FORBES: Our numbers tell us that there are very likely more species of these wasps than any other type of insect.

SOFIA: Including beetles, Nell?

GREENFIELDBOYCE: Including beetles.

SOFIA: OK. So is the reason that wasps haven't got as much attention just because the differences in wasp species is harder to, like, observe and pin down, or we just don't like them as much? What's going on?

GREENFIELDBOYCE: Well, it's kind of all of that. I mean, they're very tiny. And, you know, they sometimes are only around for brief periods of time. And, you know, when people have gone out and done kind of exhaustive looks of environments to try to see, like, every insect that's out there, and they go back year after year and, you know, sift through sand and beat the bushes and, you know, look carefully, they find a lot of parasitic wasps.

SOFIA: Right.

GREENFIELDBOYCE: I mean, I talked to this entomologist at the University of California, Davis - Lynn Kimsey. And she spent years studying, like, some desert dunes in California and rainforests in Indonesia. And she says, in each place, parasitic wasps beat out beetles.

LYNN KIMSEY: So you have to figure that for every species of beetle, there are probably at least one or two wasp parasites or parasitoids.

GREENFIELDBOYCE: I mean, that is a really tough one for people who love beetles to accept. Like...

SOFIA: (Laughter).

GREENFIELDBOYCE: I talked with Dena Smith-Nufio of the University of Colorado who studied beetles, including fossilized beetles, to try to understand what drove their intense diversity.

DENA SMITH-NUFIO: I just think they're fascinating and beautiful (laughter). So I'm going to be like the other people who root for their own little group of insects and say, well, of course the beetles are fantastic. And they're special. And they probably are the most diverse group and (laughter).

SOFIA: (Laughter). Wow, Nell. I love this, like, parasitic wasps versus beetles throwdown. In my mind, everybody wins. You know what I mean?

GREENFIELDBOYCE: Yeah, that's what she said. She basically thinks that, you know, this wasp versus beetle feud is ultimately good for science.

SMITH-NUFIO: I think it just keeps the whole endeavor rolling. Personally, I find it a lot of fun.

SOFIA: You know, I think, like - when I'm thinking about this, Nell, you know, we humans walk around feeling pretty good about ourselves, feeling pretty advanced and smart. But when you really consider how long some of these critters, especially insects, have been around, and they've had a chance to evolve and change in ways that we probably don't even understand. It's wild out there.

GREENFIELDBOYCE: Yeah, yeah. I mean, the beetles are just, like, one tiny example of that, right? You know, there's, like, all these other critters out there...

SOFIA: Yeah, right.

GREENFIELDBOYCE: ...That are even less charismatic than parasitic wasps, depending on your point of view. I mean, like, mites and worms, little tiny worms that live in the soil - I mean, they could be even more diverse. But they don't necessarily have as many fans as beetles or even wasps, for that matter.

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SOFIA: Well, they have two right here. You know what I mean, Nell Greenfieldboyce? Me and you.

GREENFIELDBOYCE: I know exactly what you mean, Maddie. I am right there with you.

SOFIA: (Laughter). All right, Nell. We appreciate you. We'll have you back on 399,000 more times.

GREENFIELDBOYCE: Yes, more to come.

SOFIA: (Laughter). This episode was produced by Brett Bachman, fact-checked by Emily Kwong and edited by Viet Le. I'm Maddie Sofia. Thanks for listening to SHORT WAVE from NPR.

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