In 1893, Belgian paleontologist Louis Dollo suggested that evolution can鈥檛 go backwards in the exact same way that it proceeded. This became known as 鈥淒ollo鈥檚 Law,鈥� and came under a lot of scrutiny. But, more recently, Dollo鈥檚 Law was co-opted into the idea that traits, once they gain a certain amount of complexity, can鈥檛 return to a simpler state. In this episode of Tiny Matters, we explore two exciting examples where scientists have found that not to be the case.
Transcript of this Episode
Deboki Chakravarti: Here at Tiny Matters, we love an old scientific publication. If you ever have a few minutes and want to have fun, dig through the archives of ACS or Nature or Science or the Royal 中国365bet中文官网, or really any journal. It鈥檚 really cool to go through these old papers and see how scientists used to write, and how the ideas they鈥檙e exploring build to what we know now.
But today we鈥檙e going to start the episode with an old article from the journal Nature. It鈥檚 not your standard article, it鈥檚 an obituary for Dr. Louis Dollo, and it was published July 11, 1931.
Sam Jones: The first line of the obituary reads: "DR. LOUIS DOLLO, who died at Brussels on April 19, will always be remembered for his numerous and valuable contributions to our knowledge of extinct vertebrate animals." And after a list of his various academic contributions, the obituary ends with "He was an acknowledged leader, with a devoted following in the new generation.鈥�
Deboki: In between those lines are the details of a scientific career that involve studying the fossils of reptiles and dinosaurs, and also a law that you might not have heard of called, appropriately enough, Dollo鈥檚 Law.
Jacob Suissa: He published this statement in 1893 that essentially, he suggests that evolution doesn't go backwards in the exact same way that it proceeded. So imagine you had a time machine, you can go back to a point in time and you can then watch a lineage evolving, and you can watch an arm evolve into a wing, and you can actually document how it happened in the steps that it happened. What Dollo is saying is that it will never go back to that ancestral state in the exact same way that it evolved there.
Deboki: That鈥檚 Jacob Suissa, an assistant professor at the University of Tennessee Knoxville, in the Department of Ecology and Evolutionary Biology. Jacob studies plant evolution, and we鈥檙e going to be talking about his work in a bit. But first we want to jump to a question we asked Jacob: what are the implications for Dollo鈥檚 Law鈥ike, is it worth considering at all?
Jacob: I think that it has a place, not in its original form. In its original form, I don't think that it is all that informative. But I think in this other way in how it's been co-opted more recently, I think it does have an interesting application.
Deboki: Welcome to Tiny Matters, a science podcast about the little things that have a big impact on our society, past and present. I鈥檓 Deboki Chakravarti, and today with my co-host Sam Jones, we鈥檙e going to be co-opting Dollo鈥檚 law to ask a question that鈥檚 both simple and complicated: can evolution go backwards?
Sam: So we have Dollo鈥檚 Law, this 19th century idea that evolution can鈥檛 go backwards in the exact same way that proceeded. And we also have Jacob, a 21st century evolutionary biologist telling us that the original form of this idea isn鈥檛 actually all that informative. And he is far from the first person to say this about Dollo鈥檚 law.
Jacob: It got criticized heavily, especially towards the middle and end of the 1950s people were saying, of course, this is more of a statistical statement. For instance, if you walk to the grocery store, what are the odds that when you walk back, you would take the exact same steps in doing so? People, particularly Steven J. Gould and Richard Dawkins were sort of like, eh, this is kind of more of a statistical statement more than a biological one. But it eventually turned and got co-opted into this idea that traits, once they gain a certain amount of complexity, don't go backwards into a simpler state.
Sam: So when Jacob says that there鈥檚 something interesting to explore in how Dollo鈥檚 Law has been co-opted today, the question he鈥檚 referring to is: if an organism evolves something that鈥檚 more complex, is that a one-way street? Or can evolution return to something simpler?
Deboki: And you could see why it might make sense that once evolution hits on something more complex鈥攍ike say, an eye or a reproductive structure like a flower鈥攊t would seem unlikely to go backwards from there. Complex structures often come with lots of advantages, like more specialization or capabilities that let you adapt to the world around you. But does nature actually follow that trajectory?
For Jacob, this is a question for the ferns. Ferns are plants that don鈥檛 have fruits or flowers. Instead, they reproduce using spores.
Jacob: They're these little dots on the underside of a fern, if you've ever looked under a leaf. And what happens is this spore will fly into the wind and germinate and actually produce a small little plant that's called the gametophyte, which is the phyte, the plant, that produces gametes, so sperm and egg. And so it actually has these two separate and independently living generations of its lifecycle.
Sam: When we talked to Jacob, he was getting ready to go teach a course about ferns in Costa Rica, which is where his interest in plant evolution began. That interest eventually led him to ferns.
Jacob: I fell in love with their diversity. I really didn't appreciate how diverse ferns were. And it was really this juxtaposition between, I think my expectations of ferns as being these ancient shade-loving, water-loving organisms with the reality, which is that they are so ecologically diverse, morphologically diverse. There are 11,000 fern species. There's more ferns than birds depending on who you ask.听
Deboki with Jacob: Is it the bird people or the fern people?
Jacob: A little bit of both. And so it was really that juxtaposition of thinking about ferns as this one thing and realizing that they're such a diverse group of organisms. That's really what pushed me in that direction.
So the evolutionary question that I fell in love with was why and how, and why do we have so much variation? Why don't we live in a world with a single leaf type or a single plant type? Why do we have all this diversity?听
Sam: One of the aspects of ferns that Jacob studies is their reproduction. Remember, ferns don鈥檛 have flowers or fruits or seeds. Instead, they rely on spores to disperse and reproduce.
Jacob: And so what that means is they put their spores on their leaves, the same structures they use for photosynthesis. And this is a very interesting thing because it means now you have one organ that has to be 鈥渙ptimized鈥� 鈥� and I'm putting air quotes around that 鈥� 鈥渙ptimized鈥� for two different functions that actually have contrasting needs or demands. So for instance, photosynthesis, when you open your stoma, those little pores in the leaves, it creates a very humid boundary layer around the leaf. And that's great for photosynthesis, but it's not good for spore dispersal because these little spore houses, called sporangia, have to dry out and open up.
Deboki: Very broadly, ferns fall into one of two camps when it comes to reproduction. The first does what Jacob just described, they combine their photosynthesis and reproduction on one leaf. This strategy is called monomorphism.
And then there鈥檚 dimorphism, which is when a fern separates those functions. They produce one type of leaf for photosynthesis, and another for spore dispersal.听
Sam: Since dimorphism requires more specialized structures and complexity than monomorphism, understanding how ferns go from monomorphism to dimorphism could teach us how complexity evolves in nature. It also gives us a way to look at that co-opted version of Dollo鈥檚 law where scientists want to know, can something that鈥檚 become complex go back to a simpler state.
So working with an undergraduate researcher named Makaleh Smith, Jacob went through natural history collections that contain pressed plants labelled with when and where they were collected, and that have been digitized to make them accessible.
Deboki: One of the first things they had to do was figure out how to actually identify whether a fern is monomorphic or dimorphic, because even though that sounds like something that should be obvious, it鈥檚 actually been a subjective call by people studying ferns.
Jacob: Botanists, pteridologists, those who study ferns, have often gone into the field and looked at a plant and said, oh, that produces spores on the same leaf it does photosynthesis with, so that鈥檚 monomorphic.听
And they'll find another plant, and it has this separation that I just described, and they'll say, oh, that's dimorphic. But there's a whole gradient actually in between. And the question really is, what are the traits that make something monomorphic? And what are the traits that make something dimorphic? And can we actually see the variation in between if we quantify some of this?听
Deboki: Using image analysis software, they were able to take different measurements on those digitized samples, looking at things like the length of the leaves and the area of spores to come up with a way to quantitatively classify the ferns by their reproductive strategy. And combining this classification with fern phylogenetic trees, Jacob and Makaleh were able to see how ferns made their way from monomorphism to dimorphism. Except鈥hings were a little weird.
Jacob: You would assume that the evolution of dimorphism goes from monomorphism to sort of an intermediary form to this full form. And we found that that is not the case. You actually rarely do that.听
Sam: If you look across all plants, you find that reproductive complexity goes up over long timescales. Like tens to hundreds of millions of years. That鈥檚 how you get flowers and fruits evolving over time. So Jacob had expected to see something similar with ferns, where you start with a simpler, monomorphic state and end up at the more complex dimorphic state.听 听But instead, the results showed that ferns could bounce around, and even more weirdly, they could go backwards.
Jacob: So once you become dimorphic, this putatively more complex state, you can go right back to monomorphic. No problem.
Sam: So ferns don鈥檛 seem to be following a co-opted version of Dollo鈥檚 law. They鈥檙e going backwards. And we wanted to know why Jacob thought that might be the case. So he took us back to the 1970s, and a pteridologist power couple: Warren H. Wagner Jr. and Florence Wagner, who hypothesized that the evolution of dimorphism in ferns would have been advantageous for a few reasons.听
Jacob: They hypothesized that the evolution of dimorphism in ferns is adaptive for several different things. So the first is once you separate these functions of photosynthesis and reproduction, you can then optimize your vegetative leaf for photosynthesis and optimize your fertile leaf for reproduction, right?听
Sam: And there are other potential adaptations of dimorphism that could have made it important to ferns as well, like being able to time spore dispersal during certain parts of the year, or orienting the leaf a particular direction, or dealing with other challenges.
Jacob: So those were some of the adaptive hypotheses that you could imagine would make being dimorphic very important. But what this suggests 鈥� and actually I'm working with some colleagues on a much bigger project looking at the evolution of reproductive complexity across all ferns 鈥� what we actually find is that monomorphism is a late evolution in ferns. It's not the ancestral state, actually. So this simpler state is not the ancestral state, and it evolved many times independently, much earlier than some of these other types of dimorphism.
Deboki with Jacob: I just want to make sure that I understand correctly. You're saying that dimorphism is probably more ancestral than monomorphism.
Jacob: A very specific type of dimorphism is the ancestral state of ferns, then you evolve monomorphism and then you evolve these other types of dimorphism. So it鈥檚 yes and no to answer your question. And what this suggests is that, instead of thinking about this more complex state, dimorphism, as the adaptive pinnacle of fern reproductive evolution, monomorphism 鈥� actually merging these two functions together 鈥� there might be some adaptive value there.
Deboki: So when I was reading about Jacob鈥檚 work, one of the questions that popped in my head was, 鈥淲ell, if nature can go backwards in evolution, can scientists also do that in the lab?鈥� And that led me to Nadine Ziemert, a professor of Microbiology and Bioinformatics at the University of Tubingen in Germany. Nadine studies antibiotics.
Nadine: I think everyone knows antibiotics as medicine that we take when we're sick. But I think not a lot of people know where they actually come from, because it's the same organisms that we fight with antibiotics 鈥� bacteria 鈥� are actually also mostly the ones who produce it. So most antibiotics on the market are actually produced originally by bacteria to fight off other enemies, other bacteria.听
Sam: Nadine told us that there are a lot of different ways that antibiotics work. Some will make it hard for bacteria to build good cell walls, so the bacteria will just pop. Others get in the way of important cell functions like DNA replication or protein synthesis.听
Like Jacob, Nadine didn鈥檛 necessarily start out interested in the thing that would become the subject of her career. Her focus was natural products, which are compounds made by living organisms. And while that does include antibiotics, she was originally studying things like toxins produced by cyanobacteria.听
Nadine: What we know from these bacteria is that they're really nature's chemists. They make such a multitude of compounds. And so we looked a little bit more into detail, looking at the genomes of these bacteria. So there's an estimate that we only know about 3% of what actually bacteria could make. There's a lot of interesting chemistry still encoded in these bacterial genomes that we have no idea what they make.听
Deboki: That work eventually led Nadine to antibiotics, and one of the motivations behind her work is the urgency to find new antibiotics as bacteria develop resistance to the ones we already have.
Nadine: And unfortunately because it's not very profitable for companies to make new antibiotics, there's actually not a lot of new antibiotics that came to the market the last couple of decades. And really in the future, that can be a major threat for our health because there are estimates that by 2050, if we don't do anything against that, then infections will be the most common cause of death again.
Sam: Because we know so little about all of the compounds that are made by bacteria, there are probably a lot of antibiotics that are just completely unknown to us. Bacteria have had a real head start on us when it comes to those antibiotics, evolving complex pathways to make structures that are hard for us humans to replicate in a lab.
Nadine: For me, the major research question there was really to see how these antibiotics diversify, to understand how nature does it because they have such complex pathways and are complex structures, it's hard to make these new compounds if you want to create new antibiotics. And so my idea was if we understand how nature does that, can we use that in synthetic biology to actually create new antibiotics that we want to make?
Deboki: So this was the other reason I was really intrigued by Nadine鈥檚 work. My background is in synthetic biology, which is a very broad field, but I like to describe it as 鈥渨e make cells do what we want them to do.鈥� And that often involves various genetic engineering techniques to get cells to produce some kind of compound or molecule that you want them to make. And in this case, Nadine and her colleagues wanted to use synthetic biology to actually go backwards in evolution, to see if they could bring an ancient antibiotic back to life.
Sam: To do this, they focused on a family of antibiotics known as glycopeptides, which work by preventing the formation of the cell wall in bacteria. No cell wall, no bacteria. Some of the important antibiotics we use today like vancomycin and teicoplanin are glycopeptides.
To study the evolution of these glycopeptide antibiotics, they looked at the gene clusters that make them possible. We often talk about proteins being made by a gene, and that can make it sound like there is one singular gene that encodes a single protein. And that can be the case. But sometimes there鈥檚 actually a whole group of genes involved in the production of a protein. These are called biosynthetic gene clusters, and they鈥檙e usually located close together in the bacterial genome. Nadine told us that these gene clusters can sometimes have as many as 70 genes in them, so they鈥檙e really complex.
Nadine: And we were looking into the evolution of these by looking how these gene clusters evolved, how new genes come in, how the whole gene cluster jumped from one bacterium to another, and really following how tiny changes in the structure of this antibiotic that also changes the actual bioactivity or the effectivity of that antibiotic. And how is that reflected in the evolution of the genes.
Deboki with Nadine: Yeah, because one of the things I was thinking about as you were saying that is obviously the genes are such a useful way to study the evolution, but there's also all this stuff that happens to make a protein that happens after the level of what's expressed in the gene. So to what extent is looking at the genes able to capture the evolution of the proteins themselves and the antibiotics?
Nadine: Yeah, that's a good question because it's these complex systems, in a lot of cases, not only make one specific compound, but a multitude of specific compounds that are somehow related to them. In general, if there are major structure differences, we can see that in the genes, it's reflected in the gene cluster. So for example, these glycopeptides, they're made from amino acids, but they only have a sugar component. And the sugar component is quite different in these different glycopeptides. They can have a glucose or rhamnose or very different kinds of sugars, complex sugars that are not easy to make. And whenever the sugar changes, we can see that in the gene clusters.听
Sam: So by looking at the evolution of different species of bacteria, along with the specific pathway encoded by the gene clusters, Nadine and her team could see that changes in the chemical structures of the antibiotic produced, for example, its sugars, reflected changes in the DNA coding for it. And this led them to believe they had found a common ancestor for these antibiotic compounds, which they called paleomycin. But one of Nadine鈥檚 colleagues, Evi Stegmann, was unsure.
Nadine: One thing that she was very skeptical at first is like, yeah but if you look at the common of this ancestor antibiotic, you see that this is actually more complex than the newer vancomycin, for example. So what happened there is the simplification of the molecule, which first doesn't seem to make sense, because you think something evolves from simple to more complex, which is not necessarily true.听
And then another thing was that she was like, yeah, but how do you know this is true and this actual pathway can make an antibiotic? And this is when I'm like, yeah, I cannot really say.听
Deboki: But by turning to synthetic biology and using their knowledge of the gene clusters that their data said would make paleomycin, Nadine and her colleagues were able to actually produce this ancient antibiotic and demonstrate that it is in fact effective, which I think is just so cool. Using the bacteria and genes and techniques we have today, scientists could go backwards in evolutionary history to not just see what an ancient antibiotic might have looked like, but actually bring it back to life so that we can better understand our modern antibiotics. It鈥檇 be like if you could have a conversation with your great-great-great-great-great-great-grandparent to understand more about why you are the way that you are.听
Sam: One of the surprising things that you heard Nadine mention is that they found the core of paleomycin is actually more complex in its structure than some of its modern descendants, like vancomycin. We asked why this might be the case.
Nadine: We still don't know. So we discussed a lot also with colleagues, and I think we can see in vancomycin that this is still highly effective. I mean, that's why we use it as a drug. But I think because it's less complex, it's just easier to make. So these antibiotics, or the antibiotic production takes a lot of energy. The more energy the bacterium needs to produce these antibiotics, the less energy it can use to grow. So I think that's always a trade off.听
Deboki: That鈥檚 just one possible explanation for what鈥檚 going on. But what was really cool about this mystery is the fact that it reminded me of the mystery of why ferns go back and forth between monomorphism and dimorphism. Obviously ferns and bacteria are very different organisms, and antibiotic production and reproductive strategies are very different processes.听
But in talking to both Jacob and Nadine, it was really striking to me how many parallels there were in what they talked about. Some of those parallels you might have already picked up on, like the fact that their work is driven by the diversity of their subjects.
Jacob: So the evolutionary question that I fell in love with was why and how, why do we have so much variation? Why don't we live in a world with a single leaf type or a single plant type?听
Nadine: Since bacteria are nature's chemists and make such a diversity, for me, the major research question there was really to see how these antibiotics diversify.听
Sam: We also asked Jacob and Nadine if they had a question in their field that they really wanted to explore but just hadn鈥檛 found a way to do it yet. And their answers were really similar: they both wanted to get back to the original.
Jacob: When we look into the fossil record, the earliest ferns are just this mess of plants that we just can't place evolutionarily. We don't know who's related to whom. We don't have any idea. And so one of my biggest questions, my sort of moonshot question is, what was the first fern? What did it look like? And how did we go from that to the over 11,000 species that we have today?听
Nadine: How did the first antibiotic evolve? How was that made and how did it look like? I think this would be a really fascinating analysis that I think we might be there at some point, but not yet.
I think there must have been more than one ancient antibiotic, right? So what was the different ancient antibiotic, the first kind of antibiotics, and how did they then evolve to this diversity we can see today? Right. That would be a question that I would love to solve.
Deboki: But to tie it all back to our co-opted Dollo鈥檚 law 鈥� this idea that when an organism evolves something that鈥檚 more complex, it won鈥檛 one day go backwards 鈥� what鈥檚 interesting is how despite working on very different questions and organisms, both Jacob and Nadine found examples from nature where things may have done just that.听
And really, what I couldn鈥檛 stop thinking about through our conversation is that maybe our idea of complexity itself is a little biased. So I asked Jacob about it.
Deboki with Jacob: The subjectivity of simple versus complex is really interesting because it made me think of to what extent do we define complexity as its similarity to us. Is seeing an eye, seeing more complex reproductive systems, is that something where we're like, that has to be more complex because it's more like us versus something that you might see in a single-celled organism?
Jacob: I think we as an engineering species tend to think that more complex is better, and as we do, as technology advances, it often gets more complex. And so I think we often apply those biases to the natural world in which it happens, of course, the evolution of the eye is a perfect example. It's an extremely complex organ that evolved several times, and it's adaptive and it's functional, but you actually have loss of eyes in lineages, especially those that end up in ecosystems that are essentially dark.听
And I would argue that complex doesn't mean more adaptive, complex doesn't mean better. Yes, even the defining it is subjective, but I mean, look, we live in a world where the majority of living organisms are bacteria, and so they're very simple, I think based on any definition or many definitions, there's probably many that you can point to them being very complex. But being more complex, being multicellular, doesn't mean you're better in any capacity at life. We live in a bacterial world, and that's just it.
Sam: Should we Tiny Show and Tell? I can go first this time if you'd like. I feel like you went first last time.
Deboki: Yeah, go for it.
Sam: I'm bringing to you what I think is a very fun Tiny Show and Tell today. It's about contagious urination.
Deboki: Sam, it's happened.
Sam: For the first time.
Deboki: Yeah. For us. I think you had one while I was gone, right?
Sam: Yes, George and I did. And it was so funny because it had never happened for us, and now it's happened.
Deboki: It's happened. We have the contagious Tiny Show and Tell.
Sam: Well, okay. We'll both share it.
Deboki: Yeah.
Sam: But I will say before we share it, I just want to plug the newsletter for Tiny Matters. I did include this one in a recent newsletter. So I put weird stuff in the newsletter like this. So I also put a link to subscribe to the newsletter in this episode's description. Let's talk about pee.
Deboki: Yeah, yeah, yeah, yeah. Let's do it.
Sam: I can just kick it off.
Deboki: Yeah, yeah. Go for it.
Sam: So a paper came out on January 20th in the journal Current Biology, titled Socially Contagious Urination in Chimpanzees. And I feel like if you see that paper title, you have to click it. It's just impossible not to.
Deboki: I was reading this in the news and I think everyone had the same response of, I need to know what this paper is about. And yeah. So basically a researcher was observing chimpanzees in a sanctuary in Kyoto, and they noticed that the Chimpanzees all seemed to pee at the same time. And they were like, is this contagious? Is this yawning? Where I start yawning, you start yawning, everyone starts running. They collected 1300 observations of chimpanzees peeing. That's hilarious to me.
Sam: It is. And it was like 600 hours, I think. Like 20 captive chimps. 600 hours, 1328 urination events.
Deboki: That's so much peeing time. Now I'm like, okay, how long was each observation? So they just found that the pee was contagious. If one chimps started peeing, another one would start peeing shortly after, and they kind of just kept going from there. And also, if they were closer, they would be more likely to start peeing.
Sam: Yeah. I think the number was around 10% of the urination events, were chimps peeing within arm's reach of a chimp that just peed. Which is like, that's pretty close, but back up a little bit.
Deboki: Yeah.
Sam: So they're like, okay, that seems slightly contagious. And then I thought it was fascinating that social rank seemed to influence if they peed. So chimps of lower dominance were more likely to follow the urination of other chimps. And I thought that was also interesting. And I guess there were some theories. Because you wonder, is it just like one chimp hears another chimp pee and they're like, "Oh, me too. I actually have to pee." Which would totally make sense. It's so hard to know exactly why. But one thing that the lead researcher, Onishi believe is her last name, I think it's Ena Onishi told NPR in the article that I read about this, that by keeping urination localized, the chimp group could maybe be reducing their risk of predators, tracking them through the scattered urine sense.
So if they're just all closer together, there's less of the ability to track them. As opposed to it's like, okay, there's pee here and then a hundred feet, there's pee here, and then another 50 feet there's pee here. So I thought that was kind of interesting too. Maybe this is a really smart adaptation.
Deboki: Yeah. I think that makes a lot of sense. I'd also read, I think in the New York Times article that I was reading about it, they suggested it could also be a way to maintain group cohesiveness. So there's kind of a social thing that's forming there. And so I immediately jumped to when you're at a dinner and one person gets up to pee and is like, "Hey, do you want to go with me?" And it's like the traditional girl exodus to the bathroom.
Sam: I was just going to say this feels like the stereotype that often rings true, where it's like girls always go to the bathroom together.
Deboki: Yeah.
Sam: Okay. Yeah. So what? Maybe we deal with contagious peeing as well.
Deboki: Yeah, exactly. We didn't need to do this study. We know. We know.
Sam: We're actually just in the bathroom talking about you, but that's fine.
Deboki: Yeah. And that's what the chimps are doing. I mean, that's what it is actually funny about this, is that it's more spontaneous. Because, originally when I saw this, I was like, oh, is this very human behavior of going to the bathroom as a group? But it's not really quite that because it almost sounds more spontaneous. I mean, maybe it sounds like we're all still learning here. It sounds more like one chimp starts peeing and others are like, "Cool, I'm going to start paying to." And not like a one chimp rings the alarm and is like, we're going to go off to this location and we're going to perform a little pee pack, and that's what's going to happen.
Sam: Right. Yeah.
Deboki: I'm so fascinated.
Sam: Yeah, it's really interesting. It's cool. It only took us... Okay, so we launched the first episode... The first full length episode of Tiny Matters was launched January 26th, 2022. The day that we are recording this... So this is not publishing until early February. But the day we're recording, this is January 24th, 2025. So it took us almost exactly three years.
Deboki: Though we didn't start doing Tiny Show and Tells until later.
Sam: That's true. That's true. We didn't start those until I think five episodes in, maybe six episodes in.
Deboki: And then I was out for a while. So it could have happened then.
Sam: That's true.
Deboki: But yeah, it took this long. It took chimps peeing in a group.
Sam: It was just such a good headline everywhere that you just couldn't not talk about it.
Deboki: Yeah. I always wonder for scientists who are doing this kind of research, do they know that we're all going to be so excited for this?
Sam: You have to. This is popular science story material.
Deboki: Yeah. Absolutely
Thanks for tuning in to this week鈥檚 episode of Tiny Matters, a podcast brought to you by the American Chemical 中国365bet中文官网 and produced by Multitude. This week鈥檚 script was written by me and edited by Michael David and by Sam, who is also our executive producer. It was fact-checked by Michelle Boucher. The Tiny Matters theme and episode sound design is by Michael Simonelli and the Charts & Leisure team.
Sam: Thanks so much to Jacob Suissa and Nadine Ziemert for joining us. A reminder that we have a newsletter! Sign up for updates on new Tiny Matters episodes, video clips from interviews, a sneak peek at upcoming episodes, and other science content we really think you鈥檒l like. We鈥檒l see ya next time.
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