Jan 17, 2014

Goo and You

On a quiet, warm summer day, somewhere in the soil beneath your feet, tucked into a nearby plant, or at the edges of a pond, a tiny little cataclysm is happening: an insect is transforming, undergoing metamorphosis. The chrysalis is easily nature’s best known black box, but it turns out, it’s one of the least understood, and most complicated: when producer Molly Webster peers inside a pupa, she witnesses some of the most complex biology happening on earth...and catches sight of an ancient question of change.

Special thanks to Lynn Riddiford, over at the Howard Hughes Medical Institute, and to Father James Martin, S.J., editor at large for America magazine.

THE LAB sticker

Unlock member-only exclusives and support the show

Exclusive Podcast Extras
Entire Podcast Archive
Listen Ad-Free
Behind-the-Scenes Content
Video Extras
Original Music & Playlists

JAD: Hey, I'm Jad Abumrad.


ROBERT: I'm Robert Krulwich.


JAD: This is Radiolab. And today ...


ROBERT: Today we are doing our Black Box hour.


JAD: Yeah, and a black box is -- it's a thing. It's a box that something goes in, you can see what that is. Something comes out which is different, and you can see that.


ROBERT: But you do not know what's going on in the middle.


JAD: It's a mystery.


MOLLY WEBSTER: I love it. Is -- shall we go inside?




JAD: And our next and final Black Box comes from our producer Molly Webster, and it begins ...


ANDREI SOURAKOV: Into the butterfly rainforest, so that you can see the butterflies that are flying, in fact.


MOLLY: So a few days ago, I was in Gainesville, Florida, at the Florida Museum of Natural History where they have a rainforest.


MOLLY: It's what, about three stories tall?


MOLLY: It's, like, got a top that's all wrapped in a net, and then it was covered in butterflies.


MOLLY: Oh my gosh, there's so many!


MOLLY: Thousands.


ANDREI SOURAKOV: Yes, so this is a heliconius butterfly.


MOLLY: That's Andrei Sourakov.


ANDREI SOURAKOV: I started looking at butterflies when I was six years old, and I have never grew up.


MOLLY: He was my guide.


ANDREI SOURAKOV: And here under this leaf you can see an owl butterfly.


MOLLY: Wow! One wing is, like, the size of my palm.


MOLLY: So there were red ones.


ANDREI SOURAKOV: Black and yellow ones.


MOLLY: Blue ones.


ANDREI SOURAKOV: Zebra-striped ones.


MOLLY: Is that -- is that a monarch?


ANDREI SOURAKOV: Yes. Watch out. Don't step on this butterfly.


MOLLY: It was like a Dr. Seuss-ian land of butterflies, but I was there to look at the moment right before they become butterflies, which remains one of the most mysterious black boxes in nature. What I'm talking about is something called ...


ANDREI SOURAKOV: The chrysalis.


JAD: The chrysalis.


MOLLY: Just to back up, at a certain point in all caterpillars' lives, after they've eaten a lot of leaves, they hit a certain weight ...


ANDREI SOURAKOV: That is coded in their gene as their final weight.


MOLLY: Some hormones start pumping, some genetics turn on, and it starts growing a little shell. That's the chrysalis. And inside that chrysalis, as we know ...


ANDREI SOURAKOV: A caterpillar becomes a butterfly or moth.


JAD: And this is a mystery?


MOLLY: What do you think happens inside the chrysalis?


JAD: I think that -- I actually have never thought about it, to be honest.


MUSEUM GUEST: I don't know. I don't -- I don't understand how it works.


MOLLY: Not many people have.


MOLLY: Are you, like, surprised that you actually don't know?


MUSEUM GUEST: Yeah, I'm surprised. I thought, like, I knew and I don't.


MOLLY: Those are folks I met at the museum.


JAD: Hey, hold up. Now that I've thought about it for a second, isn't it simply that the caterpillar is inside the shell, it sort of snuggles up, and then it grows a wing off of its right side and then off of its left side, and it just pops wings out?


MOLLY: No. That is actually what I thought, but that's not right at all.


ANDREI SOURAKOV: So McGuire Center is located on three floors.


MOLLY: Because here's the thing ...


MOLLY: Oh, so now we're going into the bowels of the building.


MOLLY: When you take one of those little black boxes and you slice it open ...


ANDREI SOURAKOV: Shall we do it?




MOLLY: Which Andrei was nice enough to do for me.




MOLLY: Even though he loves these guys. He took a tiny little chrysalis ...


ANDREI SOURAKOV: Oh, it's about an inch long.


MOLLY: Which a caterpillar had just gotten into one day ago, and he slowly began to cut.


MOLLY: So we're taking our tweezer-like scissors ...


MOLLY: ... through the outer layer of the Chrysalis until ...


MOLLY: Ah! Oh!


JAD: What?


MOLLY: Oh, my gosh!


JAD: What?


MOLLY: No, it was like there was no caterpillar there.


JAD: What do you mean?


MOLLY: There was no head. There were no legs. There was no antenna, no spiky spine.


MOLLY: It's like a pale, white yellow. It's very liquidy.


JAD: What was there then?


MOLLY: Basically just goo.


MOLLY: Just like a runny, goopy goo. Looks like snot.


MOLLY: All he had to do is give it, like, a little squeeze and then just went ...


MOLLY: Oh! Oh! [laughs] It just -- boosh! -- exploded it. He exploded it!


MOLLY: I think he looked shocked, too.


JAD: Wait, I don't understand. Where did -- where did the caterpillar go?


MOLLY: It seems like once a caterpillar gets into its shell, it sort of just melts. Its head, legs ...


ANDREI SOURAKOV: Antenna, abdomen ...


MOLLY: They all just dissolve. Muscles themselves just sort of, like, dissolve away into individual muscle cells. And some of the cells rupture and so their insides, the amino acids, the proteins, those all go floating out into space.


JAD: Wait, you're saying that the caterpillar just becomes like a soup of cells?


MOLLY: Yeah. And yet somehow ...


ANDREI SOURAKOV: This soup will magically be transformed into a butterfly or moth.


JAD: Well, how does that happen?


MOLLY: That question -- that question is the big, fat, metaphysical, quasi-religious, semi-mystical, philosophical question that people have been asking forever.


MATTHEW COBB: Yeah. So one of the big arguments that was taking place ...


MOLLY: This is Matthew Cobb. He's a biologist and historian. And he says back in the 1600s, when naturalists saw that goo, they just thought, "Oh, well clearly what's happening is that ..."


MATTHEW COBB: ... the caterpillar ...


MOLLY: ... goes into the chrysalis ...


MATTHEW COBB: ... and then it actually dies.


MOLLY: Totally dies.


MATTHEW COBB: And out of its burial cloth is going to come the new life.


MOLLY: This beautiful and completely new creature.


PHILIP CLAYTON: Death, as it were, and then a kind of resurrection.


MOLLY: That's Philip Clayton. He's a philosopher from the Claremont School of Theology. And he says from the beginning, people thought about and wrote about metamorphosis ...


PHILIP CLAYTON: ... as a kind of spiritual ascent. It says somewhere in the New Testament, "Behold, the old has passed away. The new has surely come."


MOLLY: Basically, people saw the caterpillar as a symbol of our lowly earth-bound lazy bodies, right? And then the butterfly was sort of casting away all of that and it represented our soul up in heaven, sort of in its most perfect form. Never mind that butterflies actually like to eat ...


ANDREI SOURAKOV: ... feces and urine and other unappetizing substances.


MOLLY: According to Andrei.


MOLLY: Sounds tasty. Never mind that.


MOLLY: The metaphor is, like, inspiring at some level, right? Because you think "Oh, I've got all -- I'm going to just become more -- a more perfect version of myself," right?


JAD: Yeah, yeah.


MOLLY: But then the converse side of that is, you cut open a chrysalis and it looks like a whole bunch of goo, and you think that is a hell of a lot of change. So the thing is that this transformation, either of the butterfly or of my soul, seems so dramatic, so miraculous that it made some people think, like, jeez, if you're gonna go to heaven and the process transformed that much, is it even you up there?


PHILIP CLAYTON: It still has to be you that makes it to Heaven.


MOLLY: You can't change too much. Otherwise, like, someone else will be up there enjoying your afterlife.


PHILIP CLAYTON: So certain memories and elements of your identity have to continue. Just not all the elements.


MOLLY: Yeah, I'm -- I'm so intrigued by that, because I also think, like, what -- like, what -- when you undergo such a transformation, what -- what do they think carries through?


PHILIP CLAYTON: That's a really interesting question.


MARTHA WEISS: Cleaning out the poop and throwing away the -- the moldy leaves, you have a lot of time to think.


MOLLY: Which brings us to Martha Weiss.


MARTHA WEISS: I am an associate professor of biology at Georgetown University.


MOLLY: She got to thinking about this question in more concrete terms.


MARTHA WEISS: Okay, so ...


MOLLY: She did an experiment.


MARTHA WEISS: What we did was we took a big green caterpillar, and we did something that was not entirely nice.


MOLLY: She put them in a box, filled it with a nasty odor.




MOLLY: And is the odor like an odor of a plant? Or ...


MARTHA WEISS: It's -- it's actually a plant-based odor, but it smells kind of like nail polish remover.


MOLLY: In any case, she gassed them with this nasty smell.


MARTHA WEISS: And then once they could smell the odor, then we gave them a zap.


MOLLY: Is that just like a zap? Just a zoop? A zap?


MARTHA WEISS: I think 10 seconds of zap.


MOLLY: 10 seconds.


MOLLY: And they did this over and over.


MARTHA WEISS: Odor. Zap. Odor. Zap. Odor.


MOLLY: Until eventually, most of these caterpillars learned to hate the smell. Every time they get a whiff, they head in the opposite direction.


MARTHA WEISS: Okay, so then we let them pupate.


MOLLY: Meaning the caterpillar changes into its shell and organs dissolve, muscles melt. You get this ...


MARTHA WEISS: Cataclysmic, catastrophic, chaotic.


MOLLY: Change.


MARTHA WEISS: And then ...


MOLLY: One month later ...


MARTHA WEISS: The moth emerges and now we're -- the drum roll. We're ready for the drum roll.


MOLLY: Okay. [makes drumroll sound]


MOLLY: They give the moths a whiff.


JAD: Okay.


MOLLY: And the moths hate the smell.


JAD: Hmm.


MOLLY: I mean, normally moths don't care about the smell at all. It's like 50/50. But these moths hated it.


JAD: Somehow I'm confused. What does that mean?


MOLLY: That means a memory made it through the goo.


JAD: Oh!


MOLLY: And it came out the other side.


JAD: Oh!


MOLLY: What's your -- what's your feeling, like, coming out of this?


MARTHA WEISS: My feeling is wow! I think it's amazing that a caterpillar can have an experience, go into its chrysalis, five weeks pass. Emerge as a seemingly different organism, and that it still can recall experiences that happened to it when it was a caterpillar.


JAD: And how does that happen?


MARTHA WEISS: The answer to this question is we do not know.


MOLLY: But ...




MOLLY: Out there floating in that sea of goo is actually a tiny little speck of brain. Some of the brain is dissolved away, but there's this, like, microscopic fragment that has made it through. And Martha suspects that nestled into that fragment is this memory.


JAD: Oh, it's like a little -- boop! -- it's like a little beacon.


MOLLY: And it turns out there are others, too. There's a speck of gut, some nerves, some muscle. It's not as gooey as it seems.


JAD: God, it's like -- it's like -- I can't help wondering what does the butterfly know about its caterpillar life? Like, it knows this one tiny thing, but how much else? Does it know it crawled? That it had ...


MOLLY: There's no answer to that question. But Martha says that these types of questions, like, come up all the time. In fact, one of her colleagues ...


MARTHA WEISS: And I was talking to Doug the other day, and he said that he had gotten an email from a guy who was, I'm not exactly sure what flavor of Christian, but had -- but he had gone into the whole resurrection thing. And he felt like this was, you know, when he ascended that he wondered if he would then be able to remember his life on Earth.


MOLLY: Well, here's the answer.


JAD: What answer?


MOLLY: Well, the answer to the question about what carries through. The continuity question.


JAD: Oh, right. Yes.


MOLLY: A memory carries through.


JAD: Which is freaking cool, I got to say.


MOLLY: It is freaking cool. But there's a little more freaking cool.


JAD: All right.


MOLLY: And that is that there's actually a continuity, but it goes in the reverse direction.


JAD: What does that even mean?


MOLLY: Well, Matthew Cobb told me the story about this guy.


MATTHEW COBB: This 17th-century man who I never -- had never heard of. Jan -- his name's written Swammerdam, but is probably more pronounced Svamardam.


MOLLY: Svamardam.


MATTHEW COBB: Svamardam.


MOLLY: Svamardam. Okay.


MOLLY: That's Jan Swammerdam, a Dutch microscopist from the 1600s.


MATTHEW COBB: He was definitely the first to do some very clear dissections of the chrysalis.


MOLLY: And the caterpillar. And one day ...


MATTHEW COBB: In Paris, in front of this crowd of assembled worthies, bewigged and bestockinged.


MOLLY: He gets a fat white caterpillar ...


MATTHEW COBB: Gets the scalpel or a tiny little thin bit of glass, and he dissects it. He just opens it up at the back, along its back. A long line. And what he sees inside, or what he can show them is that, in fact, there are some of the structures of the future butterfly. Its wings, its antennae, and even its legs, that are actually already formed even before pupation takes place.


MOLLY: So you peel back the skin of a caterpillar, and beneath it you see the -- a new -- the new creature hidden?


MATTHEW COBB: Absolutely. There's no decay.


MOLLY: Oh, that's so bizarre! It's like -- it's like if you were to skin me and there's my 70-year-old self is inside of me or something.


JAD: Wait, and the wings also survived the goo?


MOLLY: Yeah. So it's like the caterpillar will actually start to grow little tiny adult parts that are super thin and transparent, and it just keeps them tightly rolled up and hidden up against the edges of the chrysalis, but they don't actually ever go through the goo.


JAD: Oh!


MOLLY: Or become the goo.


MATTHEW COBB: What he'd then shown was, you know what? This isn't about death. This isn't about decay. This is actually about transformation.


MOLLY: I don't know, it's kind of eerie. Like, it's not just what of me carries forward into the future. It's like what of my future self is in me right now?


JAD: Thanks to our producers this hour: Tim Howard, Molly Webster, Jesse Cox, and thanks to you guys for listening.




ANSWERING MACHINE: Start of message.


MATTHEW COX: Hi, this is Matthew Cox.


JIM STEINMEYER: This is Jim Steinmeyer.


MARTHA WEISS: This is Martha Weiss calling from Georgetown University.


MATTHEW COX: And here are the credits.


MARTHA WEISS: Radiolab is produced by Jad Abumrad.


MATTHEW COX: Our staff includes Ellen Horne, Soren Wheeler.


MARTHA WEISS: Pat Walters.


MATTHEW COX: Pat Walters.




MATTHEW COX: Tim Howard.


MARTHA WEISS: Brenna Farrell.


MATTHEW COX: Brenna Farrell.


JIM STEINMEYER: Molly Webster.


MATTHEW COX: Molly Webster.


JIM STEINMEYER: Malissa O'Donnell.


MATTHEW COX: Malissa O'Donnell.




MATTHEW COX: Dylan Keefe.




MATTHEW COX: Jamie York.


MARTHA WEISS: Lynn Levy and Andy Mills.


JIM STEINMEYER: With help from Kelsey Padgett, Arianne Wack and Damiano Marchetti. Special thanks to Joshua Lang, Claudia Taranto, David Britland.


MATTHEW COX: Lynn Riddiford, James K. Kaczynski, and everyone at Massachusetts General Hospital. Hope that was okay. Bye.