![[BONUS] Four armadillos in a trench coat and does pregnancy boost your sense of smell?: Tiny Show and Tell Us #15 Artwork](https://www.buzzsprout.com/rails/active_storage/representations/redirect/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBCS0hiSmdnPSIsImV4cCI6bnVsbCwicHVyIjoiYmxvYl9pZCJ9fQ==--4c01c60d9d7510f2dc70a43c79c2c4201f33f5e2/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdDVG9MWm05eWJXRjBPZ2hxY0djNkUzSmxjMmw2WlY5MGIxOW1hV3hzV3docEFsZ0NhUUpZQW5zR09nbGpjbTl3T2d0alpXNTBjbVU2Q25OaGRtVnlld1k2REhGMVlXeHBkSGxwUVRvUVkyOXNiM1Z5YzNCaFkyVkpJZ2x6Y21kaUJqb0dSVlE9IiwiZXhwIjpudWxsLCJwdXIiOiJ2YXJpYXRpb24ifX0=--1924d851274c06c8fa0acdfeffb43489fc4a7fcc/Tiny%20Matters%20cover.png)
Tiny Matters
Take a dive into the genes, microbes, molecules and other tiny things that have a big impact on our world with Tiny Matters. Join scientists Sam Jones and Deboki Chakravarti as they take apart complex and contentious topics in science and help rebuild your understanding. From deadly diseases to ancient sewers to forensic toxicology, Sam and Deboki embrace the awe and messiness of science and its place in the past, present, and future. Tiny Matters releases new episodes every Wednesday and is brought to you by the American Chemical Society, a non-profit scientific organization advancing chemistry and connecting the broader scientific community. Tiny Matters is produced by Multitude.
Tiny Matters
[BONUS] Four armadillos in a trench coat and does pregnancy boost your sense of smell?: Tiny Show and Tell Us #15
In this episode of Tiny Show and Tell Us, we cover a species of armadillo that, as it turns out, is actually four species. Then we discuss what researchers know about if pregnant people have a better sense of smell.
We need your stories — they're what make these bonus episodes possible! Write in to tinymatters@acs.org *or fill out this form* with your favorite science fact or science news story for a chance to be featured.
A transcript and references for this episode can be found at acs.org/tinymatters.
Welcome to Tiny Show and Tell Us, the bonus series, where you write in with your favorite science news or factoid. We read your email aloud and then dive deeper. I'm Sam Jones and I'm here with my co-host, deboki Chakravarti.
Speaker 2:Hi Sam, I'm excited for today. I always like doing these episodes. It's just everyone writes in with such cool stories that I feel like this is sort of my way of learning all the new things that I wasn't ready.
Speaker 1:Absolutely my trivia knowledge is really going to be through the roof a year from now.
Speaker 2:And so, if you want to help contribute to our trivia knowledge, if you would like to help us dominate the next time we go, out for a trivia night.
Speaker 2:A reminder that we are always looking for you to write to us, because it makes these episodes possible. Email tinymatters at acsorg or fill out the form linked in the episode description. Let's get into it. I said that this is my way of learning something new, but actually the thing that I have for you today, sam, is actually something that is very familiar to me. So this is from listener Andrew. So Andrew writes when my wife Kay was pregnant, we were sitting in the living room of our apartment and out of nowhere, she says Can you go clean the kitchen sink? It smells disgusting. I couldn't smell anything. I walked across the living room to the kitchen. Couldn't smell anything there. I put my nose over the sink nothing.
Speaker 2:No-transcript rate their sense of smell as heightened and very poorly understood. It turns out that there's likely no difference in odor detection thresholds, identification or perceived intensity between pregnant and non-pregnant people, but there is a consistent difference in the relative pleasantness or unpleasantness of smells. The hypothesis at this point seems to be that this difference in the hedonics of smell are what drives pregnant people's apparently superhuman ability, rather than any difference in actual sensory ability. And yeah, I relate so much to Kay because when I was pregnant, things smelled gross, like I could tell when our garbage can was just like fractionally open because I could just like smell it. It was like the whole room smelled like garbage to me and then everything else just smelled awful. Like you open up your refrigerator door and you're just like hit with smells. Anecdotally, I believe this. If you Google it, you will pull up plenty of articles and Reddit threads about being pregnant and feeling very sensitive to smells.
Speaker 2:There is a 2022 meta-analysis in the journal Chemical Senses that's titled Olfaction and Pregnancy Systemic Review and Meta-Analysis, and the researchers were looking at previously published studies to see what we can learn from them about smell in pregnant and non-pregnant people. So they weren't like running their own experiments, they were just looking at all of the work that had been done previously to see what they could glean from them. Because one of the challenges is, like a lot of these studies, they use self-reporting, they have small sample sizes and their results often conflict with each other, and so we should note there are objective tools for measuring a person's olfactory abilities, but there's also like more self-reported kind of mechanisms where you're just like kind of saying this is how I smell things right now. They went through 234 papers and they found nine with enough data for this kind of meta-analysis, oh my gosh. And they ended up with a total of 523 pregnant people and 365 non-pregnant people to kind of compare. And from this they found that pregnancy was actually associated with worse odor identification when compared to control groups.
Speaker 2:But it was difficult to compare something called odor hedonics, which Andrew referred to, across these studies. So odor hedonics refers to like the pleasantness or unpleasantness of a smell. There also wasn't enough data to do a meta-analysis on odor intensity, but the authors themselves say that their results should be taken with a grain of salt because they don't have a lot of studies to work with and they note that most of the experiments for measuring olfactory ability in some kind of objective way don't really take pregnant people into account. So, going back to odor hedonics, while the study couldn't say anything definitive, there are studies using both self-reported and objective measurements that argue pregnant people find plenty of odors more unpleasant than non-pregnant people do, and so some of the ways that we could expand, like the way we do the studies, is to include more of the questions we have around pregnancy and smell, to include things like I mentioned food, like food related smells, because that's what a lot of people will complain about.
Speaker 2:It's just like suddenly food doesn't smell good. So, yeah, I thought this was really interesting to dive into more of the science of, because, you know, even if there's not a lot of science around it which is true for a lot of things pregnancy related it is also like such a vivid part of a lot of people's experiences. Like you know, smell is such an intense sense for a lot of people and when you're pregnant it can feel connected to all of these other symptoms like nausea and like food aversions and stuff. So it's a lot.
Speaker 1:It is. The olfactory system is. It's really complicated, but it's also super well defined at a granular level, like the receptors are really well defined, how they then interact, and you know how the axons from the olfactory sensory neurons project through the olfactory bulb and all that stuff. So it's interesting because it's a field that's really well understood, but there's still so many questions about it and I think with olfaction, like perception is, so it adds this other layer of complication as well. Right, so you know, you and I could be right next to each other smelling the same thing and we could say it's two different things, yeah, right. So it also makes all the self-reporting hard.
Speaker 2:Self-reporting seems kind of limited to begin with, but I didn't think about how. For smell in particular, it's probably harder to kind of normalize how you handle those different results.
Speaker 1:And I think also, beyond just being able to say like, oh, I'm smelling an orange or oh, I'm smelling a banana or whatever, we also have memories and things that are tied to those smells and maybe they're great and maybe they're bad, and so, like I might find something unappealing because it triggers some sort of like visceral reaction. Yeah, the olfactory system is so fascinating, yes, it's just really cool. And pregnancy takes it to this other level of like complication. Yeah, thanks, andrew, for sending this in. It was fun to kind of think about those complexities, for sure. So, deboki, I have a very fun one from listener Oliver. Oliver wrote in saying new armadillos Exclamation point. Oliver wrote in saying new armadillos Exclamation point. Actually, a general species of armadillo has been discovered to be four different ones. Most of the samples were recovered through roadkill, which that's a little depressing. I'm adding the it's depressing part, but that's the reality of this. So let's talk about this armadillo. That is actually four species of armadillo.
Speaker 2:It makes it sound like it's four armadillos in a trench coat.
Speaker 1:Just like stacked on top of each other To make one big mega armadillo. Oh man, I feel like I need to commission that artwork. So the nine banded armadillo is the armadillo that, as it turns out, is actually four species. So before we talk about that, I want to talk about armadillos more broadly, because I actually didn't know very much about them, other than what they look like, really knew nothing.
Speaker 1:Armadillos are part of a group of placental mammals that are native to the Americas and they include tree sloths and anteaters. I didn't know that. I think they look so different to me Maybe not so different from anteaters, but tree sloths, yeah. So they're easily identifiable by their pleated looking banded armor that gives them the appearance kind of like a roly poly. I grew up calling them potato bugs and some people call them pill bugs, but you know what I mean. So they kind of look like the mammal version of that a little bit.
Speaker 1:The name armadillo comes from the Spanish word for little armored thing, which I also think is very cute, and only the three banded armadillo can actually roll all the way up into a ball. So I thought like most of them could roll all the way up into a ball, not true, armadillos can be very big and very small. So the largest species is the giant armadillo, which is aptly named, and that can be up to 39 inches or 100 centimeters long, which is over three feet plus its tail, and weigh up to 132 pounds or 60 kilograms. That is a dense animal. And then the smallest species, which I think you should Google right now, is called the pink fairy armadillo, and it can be up to five inches long and weighs up to eight ounces. It's really cute. It kind of looks like a piece of sashimi is on its back.
Speaker 2:Yeah, Like it looks like shrimp. Oh, it's so cute, like it's really cute.
Speaker 1:So yeah, if you're not driving, look up the pink fairy armadillo, because I thought it was very cute. It kind of looks like a funny Pokemon. Yeah, totally so. Ari Remmel, who did the research for this episode, said that one unfortunate thing they learned about armadillos they couldn't remember, but either in Ed Yong's An Immense World or Ben Goldfarb's Crossings was that nine banded armadillos can jump about three feet into the air when they're startled and apparently that works really really well for them, or has worked really well for them, as a defense mechanism over evolutionary time, especially because they don't have great vision. So just like I'm going to jump, which also makes them seem like a cartoon character or something they're just like, yeah, I'm going to hop up.
Speaker 2:Like three feet is tall, that's a long way to curl your body off the ground and you don't look at an armadillo and think that that's a jumper.
Speaker 1:Yeah, I'm not thinking about their athleticism when I look at them, but unfortunately the problem now is that on active roadways this can mean that they actually jump directly into the undercarriage or front bumper of a moving vehicle, like it would be much better if they didn't jump right, and it's a reason that armadillos have become really common roadkill. That is sad. So a fun fact that Ari found on the San Diego Zoo website is that the nine-banded armadillo, which is the one that actually is four species, has four identical pups in every litter, either all male or all female, and the seven-banded armadillo produces between eight and 15 identical offspring, which is so fascinating to me. Yeah, that was a little side note, but let's talk about the nine-banded armadillo. So the original species, the nine-banded armadillo, was also known as the long-nosed armadillo, and it was one of the most widespread, with a range from Argentina to the United States Makes sense. It was the most widespread because it's actually four species. You can cover a lot more ground when you're all pretending to be the same thing. No, I'm not blaming the armadillo, this is on us.
Speaker 1:The nine-banded or long-nosed armadillo is the official state mammal of Texas. Of course, I don't know if you knew that you marry a Texan. You learn too much about Texas. I was going to say I thought there might be a chance. So they're generally insectivores and they use their long nose and claws to dig and forage for food. So armadillo researchers had noticed some genetic anomalies in specimens collected from different regions that were previously recognized as a few different subspecies, but there wasn't enough evidence to suggest that they were actually distinct species till now. So this new study used mitochondrial DNA from more than 70 museum specimens that have been collected across the animal's range, and they found four distinct lineages that are now accepted as different species, and this paper was published in Systematic Biology in June 2024.
Speaker 1:The nine-banded armadillo in the US and Mexico will now be called the Mexican long-nosed armadillo, which Ari wrote. Like I wonder if the state of Texas is just going to like ignore the species, change, texas doesn't care. They're like, yeah, whatever, or maybe remove it as the official state mammal, but like we'll have to see Texas balls in your court. And then another subspecies was elevated to a full species and the original nine-banded armadillo is now restricted to South America. And directly from the press release from the Field Museum about this, they say Meanwhile, the data showed that another branch of the armadillo family tree didn't belong to any of these three pre-existing groups.
Speaker 1:So you have those three and then you have another one. That's like what? What do we do with this? Yeah, a region of northeastern South America known as the Guiana Shield is home to the newest armadillo species, the Guianan long-nosed armadillo. So that's number four. Armadillo, so that's number four. The new armadillo is a bit bigger than the other three species, has a hairless shell, a robust dome-shaped skull and an additional bone in its spine which I kind of am like guys.
Speaker 2:Why did we ever think that this was part of the same? I mean, this whole thing is fascinating, because learning how complicated taxonomy is has been fascinating.
Speaker 2:So our last episode of this, we talked about convergent and divergent evolution and we're talking about like these species that live in madagascar, that look a lot like hedgehogs and possums and shrews that live in other countries, and it's like initially like when we were just naming all these animals or people were kind of understanding them, we were just going off of what they looked like, it's true, and so it's so easy to group like animals and organisms together where you're like obviously they're related, they look so much like each other and then really it's been DNA that's done a lot to like, reveal how unrelated a lot of animals are, but in really cool ways, where again you see these things converging or, in this case, you see like a bunch of species that could potentially be the same, like.
Speaker 2:I think what the armadillo example is making me think of is also how complicated delineating a species is. You have these subspecies and you have things that are just kind of sort of the same but not, and it's just, it's so complicated and messy and I love, like these reminders that sometimes we draw these boundaries, but nature is actually like a lot more fluid than that. Oh yeah, and also because maybe what this is more about is the fact that we draw these boundaries in ways that can sometimes obscure what's going on, because we need to, we do need to be able to say, like this is the species, but also it means that sometimes we might see like a different bone in the spine and just think, oh, this is like a funny little specimen, totally.
Speaker 1:I think part of what you maybe we're getting at I don't know if you were but like we have to define species and part of that is for conservation efforts, right?
Speaker 1:Like you need to know what exists, to know what you need to protect the most.
Speaker 1:In the press release from the Field Museum, there's a quote from the co-author of this new study, who's also the assistant curator of mammals at the Field Museum in Chicago, and they say sometimes biologists bring individuals from one area to another to repopulate. Since they're different species with potentially different needs, they will not be able to integrate and so, while the nine-banded armadillo has not been considered endangered quote this discovery totally shifts the way we think about conservation for these species and the way we think about how threatened they are. So I thought that was like of course, right, like if these are really different species, you can't just throw them all together and say, cool, repopulate, yeah, they might need really different things and genetically they're different enough that it might not work super well. So yeah, that's really fascinating. I love when people figure out that you know when it comes to species, or like discovering maybe like it's an archaeological dig and you discover something that then throws off what we thought about the ancestor of something that's living today and I always think that's so.
Speaker 1:It's so fascinating.
Speaker 2:Thank you to Andrew and Oliver for writing into us and thank you for tuning in to Tiny Show and Tell Us a bonus episode from Tiny Matters, created by the American Chemical Society and produced by Multitude. And a big thank you to science journalist Ariana Remmel who did the research for this episode.
Speaker 1:Send us an email to be featured in a future Tiny Show and Tell Us episode at tinymattersatacsorg, or fill out the form linked in the episode description. We'll see you next time.
