Do Fossil Prints Show Dinosaur Flight Evolved More Than Once?
12:15 minutes
Researchers studying tracks fossilized in Cretaceous-era lakeshore mud in what is now South Korea argue this week in Proceedings of the National Academy of Sciences that the dinosaur footprints are “indirect evidence of pre-avian aerial behavior” in a tiny microraptor.
The tracks, which belong to a sparrow-sized theropod related to Tyrannosaurus rex, are spaced far enough apart to indicate that the tiny dino was moving across the mud very quickly. That speed, the researchers argue, is faster than the animal should have been able to go just by running with its hindlimbs. However, if flapping wings were added into the equation to give a power boost, the spacing might make sense.
If the microraptor did, in fact, have flight-capable wings, that would mean that the ability to fly may have evolved in multiple lineages of dinosaurs, not just the descendants of Archaeopteryx we see as modern birds. Other researchers are not convinced of the analysis, arguing that the tracks may not all have come from the same individual at the same time.
Jason Dinh, climate editor for Atmos, joins guest host Sophie Bushswick to talk about the debate, and other stories from the week in science, including an archeological find of medieval-era Silk Road cities in the Uzbek mountains, breathing differences in people born with the inability to smell, and the surprising ability of hornets to hold their liquor.
Jason P. Dinh is Climate Editor at Atmos Magazine in Washington, DC. He previously was an NSF-funded intern at Science Friday.
SOPHIE BUSHWICK: This is Science Friday. I’m Sophie Bushwick, senior news editor at New Scientist, and I’m sitting in for Ira Flatow.
Later in the hour, the science behind a touchy political issue, third-trimester abortions, and how a California wildfire is having an unexpected benefit for butterflies. But first, you may have encountered a protest that disrupted your day, blocking traffic on your route to work, for instance. And maybe you grumbled to yourself that this sort of disruptive protest is not winning any hearts and minds. But new research finds that it could actually have a positive effect.
Here to talk more about that and other stories from the week in science is Jason Dinh, climate editor at Atmos, in Washington, DC. Welcome back, Jason.
JASON DINH: Thanks for having me.
SOPHIE BUSHWICK: OK, so tell me about this study.
JASON DINH: Yeah, I think some listeners may find this result to be quite surprising, but in this new study that was published in the journal Nature Sustainability, social scientists found that disruptive, high-profile climate protests can actually boost public support for moderate climate groups. This runs counter to a widespread opposition we often hear whenever these more fringe demonstrations happen, right? There’s this gut feeling that disrupting people’s lives might hurt support for social movements. But this study showed that that isn’t the case, and in fact, it can actually increase support.
This particular study looked at a case from the UK, in 2022, when the group Just Stop Oil shut down the country’s busiest motorway, the M25, for four days. They found that, within weeks of that demonstration happening, public support for more moderate environmental groups, like Friends of the Earth, increased. And scientists and activists have theorized that these radical fringes of social movements might have this type of consensus-building effect. But this is really the first time they’ve been able to test it in real time in response to an actual protest.
SOPHIE BUSHWICK: So the research was just looking at this one specific protest, not some of the other forms of disruption we’ve seen, like the people who throw soup on famous paintings?
JASON DINH: Yeah, exactly. They polled about 1,400 people in response to this particular protest.
SOPHIE BUSHWICK: And do they know why people increase their support for the environmental cause even though they had to put up with this action that might have annoyed them personally?
JASON DINH: So we can’t really point to a precise mechanism based on this study. And the reason why any individual changes their minds is probably going to differ person to person. But, in general, the finding supports this hypothesis, called the radical flank effect, where there’s a heightened awareness of an issue sparked by a radical group, and that increases solidarity with and support for the more moderate ones.
SOPHIE BUSHWICK: OK. Stepping back in time for a moment, you also have a story this week about a tiny feathered dinosaur.
JASON DINH: Yeah, what a great hook, right? This study was published in the Journal PNAS, and it analyzed these fossilized footprints that were left behind by a tiny raptor– so a relative of T-rex– that was about the size of a sparrow. And the distance between consecutive footsteps on one set of these dinosaur tracks were so far apart that the scientists who published the study said that the animal must have been flapping its wings to generate lift and lengthen its stride to be able to produce them. Some even think that this track might have been left behind as the dinosaur was taking off for flight, like a plane accelerating down the runway before it goes airborne.
And the really interesting part about this theory is that this species isn’t part of the dinosaur lineage that eventually evolved into birds. So if the theory holds up, it could suggest that flying evolved multiple times across different dinosaur lineages.
SOPHIE BUSHWICK: I have to say, this image of a tiny T-rex running at top speed while flapping its arms is extremely cute.
JASON DINH: Yeah, it would a great Pixar movie.
SOPHIE BUSHWICK: [LAUGHS] But not everyone agrees on this interpretation, right?
JASON DINH: Yeah, that’s right. There are definitely skeptics. So this is all based on a comparison between just two tracks of footprints. Some skeptics say that maybe that track has footprints from multiple individuals, not one individual. Others think that maybe they don’t actually represent consecutive footprints. Maybe some of the intervening ones were erased over time. But the study authors are pretty insistent, even though they want to be conservative, that they suspect that this is some sort of preflight run.
SOPHIE BUSHWICK: And going even further back in time, let’s look back to when the planet was largely a water world, and then an ancient asteroid came along.
JASON DINH: Yeah. So this goes all the way back 3 billion years, to Earth’s early history. And just to paint the picture for you, Earth was mostly water at the time. There were a few volcanoes and large islands that jutted out above the sea surface, and there was very little life, aside from microbes. And this asteroid that these researchers studied, named S2, was about 50 to 200 times larger than the one that killed the dinosaurs.
SOPHIE BUSHWICK: Wow.
JASON DINH: The surprising result here is that, although this asteroid was pretty devastating when it hit Earth, it may have been beneficial to life in the short to medium term. So when this asteroid hit Earth, it basically caused these massive tsunamis. It evaporated the top layer of the ocean. And it sent up up to 10,000 cubic kilometers of debris into space. And that blocked out the sun. All that debris eventually recondensed as these molten droplets that then rains back down onto the surface of the Earth.
So, as you can imagine, that’s pretty devastating. But they say that only lasted a few years, maybe a few decades. But after all of that dust settled– apparently the seas were starved for nutrients at the time– and this asteroid actually brought 360 billion metric tons of phosphorus, a really critical nutrient, from space into the oceans. And the tsunamis that it caused circulated the oceans in a way that lifted iron and other nutrients from the deep up to the surface, where primitive photosynthesizing microbes could use them.
So essentially, it was this huge extraterrestrial fertilizer for early Earth. The scientists who did this study compared it to brushing your teeth, where you wipe out a whole bunch of the microbes in the morning, but, by midday, a bunch of them are resilient and they bounce back.
SOPHIE BUSHWICK: Let’s skip back forward in time again to the time of the Silk Road. Tell us about this story.
JASON DINH: If you remember back to your history lessons, the Silk Road was this famous network of trade routes that connected Europe and China for about 1,500 years. It was really long thought that all of the major hubs in the network were these low-altitude cities that had enough water and fertile land to cope with harsh desert conditions. But now, in the journal Nature, scientists reported that they discovered a previously unknown city within the Silk Road that’s 2000 meters up in the mountains of modern-day Uzbekistan.
And this is a really major discovery because cities were rarely built at high altitudes in medieval times. There are only a few that we know of, like Cusco, in Peru, or Lhasa, in Tibet. And one expert, who wasn’t involved in this study, even told Science that the discovery of this mountain metropolis could force us to rethink what the Silk Road looked like, but it could also rewrite the history of Central Asia more broadly.
SOPHIE BUSHWICK: Wow. Do we know what people were doing up there in the mountains then?
JASON DINH: Yes. So based on the excavations that they were doing, they found that there was a pretty big foundry and a furnace and a ton of iron ore nearby. So they think that the city was a big steel manufacturer and exporter. And because there weren’t many permanent structures within the fortified parts of the city, they also think that the residents were highly mobile. So maybe they were sheep or goat herders, who pitched yurts up in the mountains during the summer but went back to the lowlands when it got cold in the winter.
SOPHIE BUSHWICK: Changing directions entirely, there’s a story this week about the people who are born without the ability to smell.
JASON DINH: Yes, this new study was published in Nature Communications. And it found that people who are born without a sense of smell breathe differently than those who have a typical sense of smell. Essentially, the shapes of the inhales and exhales differ between those two groups. And the most obvious difference was that people with a typical sense of smell tended to have a tiny inhalation peak at the top of their breath, as if they were investigating their environment for different smells and odors.
They made these conclusions based on a data set with just over 50 people. Twenty-one of them were born without smell, 31 of them had a typical sense of smell. And the researchers gave them these relatively unobstructive devices that could measure nasal breathing continuously for 24 hours. And then they sent them home, wearing this device, to go about the rest of their day.
When the researchers got the data back and were able to spot these subtle differences in breath, they could actually build a predictive model that could guess with 83% accuracy whether a person was born with their sense of smell or not, based solely on the differences in their breathing.
SOPHIE BUSHWICK: And what’s the value of knowing this? How does this help us?
JASON DINH: The authors think that this might be related to a bevy of health effects that arise when people don’t have a sense of smell, like depression or early mortality. But a lot of outside experts say that it’s way too premature to make those leaps of causality and there needs to be a lot more research done before we can start thinking about that.
SOPHIE BUSHWICK: Staying on the health track for a moment, there’s also news this week from a trial of people with depression who used a brain stimulation technique.
JASON DINH: Yeah, these results come from a phase II trial for this new depression treatment. And they were published in the journal Nature Medicine. They’re looking into this novel treatment that applies tiny currents of electrical stimulation to the brain, specifically in areas that are known to be affected by depression. Basically, patients put on this headset, wearing two electrodes that apply this current. And they wear it for half an hour at a time a few times a week over the course of 10 weeks. In this trial, the patients were actually self-administering this treatment from their own homes while they were being supervised by the researchers conducting this study.
And compared to the control group, those that received this treatment were twice as likely to have their depression go into remission. So about 45% of them did. And if this treatment goes on to get approved, it could be a game changer on a few fronts. It could be huge for the 1/3 or so of depression patients who never go into remission using current psychotherapies and medications. And depending on how well it’s implemented, it could also be a big boost to health care accessibility. The treatment can be done in your home as you go about your normal life, and there’s no need to find and go to a specialized clinic every day.
Of course, there’s some doubt, as the trials always have. But even some of the skeptics have told journalists that they agree with the authors that this could be really helpful to patients, and it’s definitely worth studying further.
SOPHIE BUSHWICK: Finally, the most important finding, in my opinion, from this week is about hornets and alcohol. Tell us about that.
JASON DINH: This new study showed that the Oriental hornet, which is a type of wasp that’s about an inch long, can drink 80% alcohol and show no ill health effects or behavioral changes. This is a level of alcohol tolerance that’s not known in any other animal.
SOPHIE BUSHWICK: Wow.
JASON DINH: And although the study sounds kind of silly, it’s actually quite important from a biological standpoint. Hornets and a lot of other animals eat ripe fruits, which can naturally ferment and produce ethanol. And ethanol has a calorie density that’s almost double that of sugar. So it can be a great nutrient source as long as you can handle the unintended side effects of it.
SOPHIE BUSHWICK: So if you are celebrating anything this weekend with a hornet, please do so responsibly. Thanks so much, Jason.
JASON DINH: Thank you.
SOPHIE BUSHWICK: Jason Dinh is climate editor at Atmos, in Washington, DC.
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