MARY LOUISE KELLY, HOST:
It is time, once again, for our science news roundup from Short Wave. That is NPR's science podcast. Reporting this time, Regina Barber and Rachel Carlson. Welcome, you two.
RACHEL CARLSON, BYLINE: Hey, Mary Louise.
REGINA BARBER, BYLINE: Hi.
KELLY: Hey. So you have brought us three science stories that caught your attention this week. I have to say, there are some real mindbenders this time.
CARLSON: Yeah, we have a little bit of everything for you, from a device that shows people have unique breathing fingerprints...
BARBER: ...To what's really in a dinosaur's stomach...
CARLSON: ...And an unexpected reason why droughts are getting worse.
KELLY: OK, let's take them in order. Humans with unique breathing fingerprints? Explain.
CARLSON: Yeah. OK, Mary Louise, Gina, I want you both to take a big breath through your noses.
KELLY: Through our noses.
BARBER: I was, like, holding my breath.
KELLY: OK.
(SOUNDBITE OF INHALING)
CARLSON: So that sniff you just took...
KELLY: Can we breathe out?
(LAUGHTER)
CARLSON: You can breathe out. You can breathe out.
(LAUGHTER)
KELLY: OK, we're ready.
CARLSON: OK. That sniff you just took is giving your brain information about your environment - the studio you're in.
NOAM SOBEL: We view the world through the nose. When you inhale - namely sniff...
(SOUNDBITE OF SNIFFING)
SOBEL: ...Then you have information, and if you're not sniffing, you don't have information, period.
BARBER: (Laughter).
CARLSON: That's Noam Sobel. He's a neurobiologist and one of the study authors for this paper that came out this week in the journal Current Biology. He told me the olfactory system - like our noses, nasal breathing, our sense of smell - is really important for how the human brain functions. Every breath we take is linked to how we interpret and move through the world. Like, for one example, when we're planning out our language, or even during this conversation we're having now, our noses are involved. We have to figure out when to breathe. Or when we're doing things like working out. Our noses are important, basically.
BARBER: So Noam says since people's brains are unique, he and other researchers wondered if human nasal breathing patterns were, like, also unique. So he and his team developed this device that monitored a hundred people's airflow for 24 hours, and participants wore it while they went through their daily activities. It kind of looked like those small oxygen tubes that go in your nose.
KELLY: I am picturing this. OK. But I am struggling to wrap my head around the idea that we humans all have unique nasal fingerprints. Explain that.
CARLSON: Yeah. So they saw that just based on people's breathing patterns, they could tell how participants were likely to score on levels of depression, the kind of sleep they were getting, anxiety.
KELLY: Wow.
CARLSON: So for example, people who scored higher on anxiety questionnaires also had shorter inhales than people who scored lower on those questionnaires, even though none of the participants had actually been diagnosed with anxiety. So Noam says he wonders if this tool could be used to help identify mental or physical health problems in the future.
KELLY: Well - and I'm wondering about what's cause and what's effect here. Like, if we can change the way we breathe, could that change our health?
BARBER: So this study can't tell researchers that, but Noam says hopefully with more research and new tools, we can learn more about, like, whether breathing could make a difference for things like anxiety or depression.
KELLY: All right. My yoga instructor and I will be paying close attention to...
(LAUGHTER)
BARBER: I think many people will, yeah.
KELLY: ...Future studies. All right. Breathing deeply through my nose.
(SOUNDBITE OF INHALING)
KELLY: Moving on.
BARBER: (Laughter).
KELLY: Dinosaurs eating.
BARBER: Yeah.
KELLY: Regina, what we got?
BARBER: Yeah. Specifically, we're going to talk about a sauropod's last meal. So sauropods are huge dinosaurs, like, over 50 feet tall, with long necks, small heads. They also eat plants. Think Littlefoot from "Land Before Time," or, like, the Sinclair Oil logo.
KELLY: This is, like, your stereotypical, classic brontosaurus-looking...
BARBER: Exactly.
KELLY: ...Dinosaur.
BARBER: Yes.
KELLY: Go on.
CARLSON: Yeah, and paleontologists have labeled them herbivores - vegetarians - based on educated guesses from things like their teeth and their body shape.
STEPHEN POROPAT: There's a reason every kid knows that sauropod dinosaurs ate plants. It's because, first of all, it's hard to imagine them eating anything else, but also because scientists have thought about exactly how they were able to do that. They don't chew. They snip and swallow, and then they ferment.
CARLSON: That's paleontologist Stephen Poropat, who's the lead author on a study published in the journal Current Biology. For the first time, Stephen and a team of paleontologists and volunteers in Queensland, Australia, found the preserved gut contents of a sauropod.
KELLY: The preserved gut contents.
CARLSON: Yeah.
KELLY: What were they?
BARBER: Yeah. So once they confirmed that, like, these fossils were truly, like, just from the stomach, they saw a variety of plants, like, even conifers, like, pine trees we have today.
POROPAT: We know from other fossils what kind of plants were available, but we wouldn't necessarily expect all of them to be on the menu.
CARLSON: So Stephen says he was surprised to see flowering plants in the gut which had just shown up during the Cretaceous period when this dinosaur lived. So he says the evolution of flowering plants might have affected the evolution of sauropods, too.
BARBER: And vice versa. By the way, they named the dinosaur Judy, after one of the founders of the Australian Age of Dinosaurs Museum in Winton, Queensland. And we should say that Judy the dino is, like, one data point. It's what Judy last ate. So Stephen and other paleontologists are, like, cautious about generalizing all sauropod diets based on this, like, one finding, but it's a good start.
KELLY: All right. Topic three. Let's move on to our last one. This is why droughts are getting worse. I'm going to go out on a limb here and venture this might be linked to climate change?
CARLSON: Yes, but it's not only because there's less rain. So recent work published in the journal Nature found that one reason droughts could be getting worse is because the atmosphere is getting thirstier.
KELLY: Thirstier - explain that.
BARBER: Yeah. One climate scientist who worked on this study, Chris Funk, says it has to do with the chemistry of the atmosphere.
CHRIS FUNK: As nitrogen and oxygen molecules heat up, they bounce around more, and that leaves more space in between them for water vapor.
BARBER: So when the air is warmer, like with climate change, the atmosphere can hold more moisture. It can pull water from, like, rivers, lakes and soil. Scientists have known that both of these things happen, but since with climate change extreme rainfall events are also increasing, they didn't know how big of an effect it was having.
KELLY: So how did they figure that out, which effect was the more powerful?
CARLSON: They used a big computer model, which is something lots of other climate studies do. The scientists fed it both rainfall and evaporation data from a 40-year span - 1981 to 2022 - and then they looked at drought trends. And they found that the global drought area jumped from 10- to 30%, with drought levels really accelerating in the last five years of the study.
BARBER: And because of the warmer and thus, like, thirstier atmosphere, droughts got 40% worse in the period they studied. And in some places, droughts were 60% worse because of it, like in Africa, South America, Australia and the southwest U.S.
KELLY: OK, so let me try to just get this in layman's terms. You're telling me droughts are getting worse, and we think this is because the atmosphere is warmer, so it can suck up water faster than rainfall can replace it?
CARLSON: Yes.
KELLY: OK.
CARLSON: Which means dry areas are getting drier, but wet areas are also getting drier. We talked to hydrologist Yadu Pokhrel, who wasn't involved in the work, and he says, because this effect has gotten worse in the last five years of the study...
YADU POKHREL: It indicates that this may further intensify in the coming five years, 10 years, and we may have a dire situation.
CARLSON: He also mentioned that future work could include looking at different categories of drought other than atmospheric drought, so, like, water availability in streams, aquifers or soil.
KELLY: Well, it does sound dire. Now that they've figured this out, or think they've figured it out, what can scientists actually do with this information?
BARBER: Yeah, understanding how this atmospheric thirst affects drought can help people anticipate when it could cause famine, which could give folks a heads-up to prepare for impacts to their crops and livestock.
KELLY: That is Regina Barber and Rachel Carlson from NPR's science podcast Short Wave, which you can follow for new discoveries and everyday mysteries and all the science behind the headlines. Thank you both.
CARLSON: Thank you.
BARBER: Thank you.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
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