Short Wave - How did these flowers evolve to survive a megadrought?

Episode Date: March 20, 2026

A multi-year megadrought in the Western U.S. has claimed untold populations of wild plants. Amid the conditions, some have survived. Scientists have produced a stunningly complete picture about how populations of one particular flower – the scarlet monkeyflower – made it through. In a new study published in the journal Science, a team of scientists spent decades studying and sampling select populations of scarlet monkeyflowers in California and Oregon. Through genetic sequencing, the team discovered that the populations that did best went through genetic changes in a short time period. This is known as rapid evolution. The team found that three of the populations that recovered the BEST adapted their stomata to open less, so they could conserve more water. Stomata act like a plant’s pores, managing gas exchange and water loss. This allowed the scarlet monkeyflowers to hunker down in the drought and survive. Interested in more stories about rapid evolution? Email us your question at [e-mail] to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Listen to Short Wave on Spotify and Apple Podcasts.This episode was produced by Jeffrey Pierre, Rachel Carlson and Hannah Chinn. It was edited by Christopher Intagliata and Rebecca Ramirez. Aru Nair checked the facts. The audio engineers were Becky Brown and Robert Rodriguez.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, Shortwavers, Emily Kwong here. And Nate Roth, hello. Hello. And today we have our biweekly science news roundup featuring the host of All Things Considered. And here with us is the glorious Elsa Chang. Hi, hi, hi, hi. Okay, here we're going to be talking about the social lives of sharks.

Yes, and we have another story about a rapidly evolving wildflower. And another that looks at a, let's call it counterintuitive, grooming behavior in birds. All that on this episode of Shortwave, the science podcast from NPR. Okay, Elsa, which story do you want to start with? Ooh, well, I want to start with the wildflowers. Lovely. Good choice.

Yes, allow me to introduce you to the scarlet monkey flower. That is a plant with vibrant red petals whose flowers kind of look like a grinning monkey. That's amazing. It is a plant that's bright red that has all this kind of pollen up front that's really set up for a hummingbird to just kind of fly in. and drink some nectar. Plant biologist Daniel Ansted at Cornell University said that without water, these flowers will die in a few days. However, several wild populations in California and Oregon survived this intense megadrought.

Wow. Yeah, this wildflower mystery is the focus of a new paper in the journal Science. Wait, so what are the monkey flower's secrets to survival? Well, Elsie, it turns out some wild populations are able to survive this exceptional drought through something called rapid evolution. It's when populations go through genetic changes in a very short time period. So cool. Okay, so which traits did these surviving flowers have?

Yeah, the scientists found that three of the populations that recovered the best adapted their stomata to open less. Stomata? Yeah, so they could conserve more water. Stomata, yeah, that's basically like a plant's pores. And this allowed the scarlet monkey flowers to hunker down in the drought. Slow and steady, survive. Slow and steady. How did the scientists even figure this out? Well, so they looked at the same populations of scarlet monkey flowers for over a decade.

They hiked out to these, like, remote populations of monkey flowers checking which plants lived, which died, and they collected their seeds for genetic sequencing. And Daniel hopes this work will continue for decades, just like the long-term studies on Charles Darwin's famous vincers in the Galapagos. That's what we hope to build with this study, is this long-term study, because, yes, rapid evolution has. happen. Great. Those populations did good in one time point. But what are the longer decado consequences? Like, so what if an insect comes along or there's a prolonged period of rain? Well, the survivors have enough genetic variation within them to respond again? That's kind of the role the dice that evolution brings, and this is the kind of science that shows how it all goes down. Fascinating. But I am still

processing how a flower can look like a grinning monkey. Anyway, next topic, bathing birds? Tell me more. Yeah, so Elsa, it's not the kind of bathing that you might be thinking of. This study looks at the mechanics of something called dust bathing, which I'm embarrassed to admit. I didn't even know it was like a thing. Me neither. Sounds like a great spa treatment. Go ahead, Emily. I did it this morning.

I highly recommend. No, dust bathing ostriches do it. Some species of songbirds, turkeys and chickens. Patricia Yang and assistant professor at National Singhua University in Taiwan says a bath for a chicken involves dirt and sand. Ouch. And the chickens start, like, digging themselves into the mud and start, like, wiggling their wings and then put the sand on them. Sand does not sound comfortable to me at all. Right.

It sounds a bit counterproductive, but scientists have actually known for a while that it's a pretty useful behavior. Because it helps birds maintain the right amount of oil on their feathers, kind of like a dry shampoo, right? You might do that, Elsa. And it helps them get rid of parasites. Tiny little bugs like feather mites, which can. can burrow into a bird's plumage and cause itching, scabbing, anemia, and all sorts of other bad things. Wait, but how does taking a dirt or sand bath help a bird get rid of all those gross parasites and bugs? So, yeah, so that's what Yang really wanted to find out with this new study, which published in the proceedings of the National Academy of Sciences.

And to do that, she ran an experiment where she collected sand and that a bunch of mite-covered chicken feathers from a farm on Taiwan. And then they vibrated those feathers in the sand at a rate of furrowing. four to five times per second. The same frequency, chickens usually reach shaking their wings during dust baths. And almost all of the mites fell off. I wonder if this would work with humans who have lice. Can you imagine? You're welcome to try it out.

In a sandbox. You make some sand. The next time I get new fistic, guys. I mean, yeah, so to put it another way, what happened here? I mean, basically what the birds are doing is sandblasting themselves. That's Andrew Dickerson, a mechanical and aerospace engineer at the University of Tennessee, Knoxville. And he was not involved in this new study, but he has researched the frequency at which dogs shake their body to rid themselves of water. And he says the new paper backs up one of the things that he's found that animals have some pretty finely tuned ways of getting rid of contaminants like mites or water, be it shaking off or agitating sand.

And maybe there's something that engineers and technologists can learn from those behaviors. Wow. Okay. Now for our final topic, sharks? That is correct. And as a surfer, this paper totally caught my eye because bull sharks have friends. Oh, wait, what's it bull shark again? Bull sharks, they are found worldwide in warm, shallow waters, and they're really big.

Like, females can grow about three meters or 11 feet. And what's cool about this paper is they, yeah, they're really social and they like hanging out with each other. Wait, they're like friendly. They're like gregarious sharks. Well, what the paper is saying is basically individual sharks seem to have a distinct preference for some sharks over others. Yeah, Natasha Morosi is a shark scientist, and she and her team looked at 184 bull sharks over six years in the shark reef marine reserve in Fiji. They observe sharks by tagging them and through video recordings of dives. And get this also, Natasha can actually tell who's who just by like looking at their wounds or scars.

And sometimes just by the way they swim. And as far as the shark's social lives, the researchers saw some sharks consistently hang out with each other over the course of the study. Like these perfectly named three pals. Chunky and mogul and shark bite were like the boys club. Chunky, mocal and shark bite the boys club. I love it. Wait, wait, but these sharks are just like swimming near each other, right? Like, how do we know that is evidence of the sharks actually being social? Yeah, so in this study, Natasha says they looked at specific behaviors to,

see if sharks are making active choices about who to hang out with. So that meant if they swam parallel to one another or if they changed direction to join or follow another shark. Yeah, and the team found that a shark's age made a difference in who they associated with. Middle-age bull sharks tended to be at the center of social networks with more connections than younger or older sharks. Interesting. Yeah, and a shark researcher who didn't work on this paper, Catherine McDonald also cautioned against too many comparisons to human friendship, since we don't really know what these interactions mean. The results are. in the journal Animal Behavior, and Elsa, just a reminder that scientists do have a sense of humor.

The title of this paper is Rolling in the Deep. Nice. Elsa, so fun to have you on. So fun. I love hanging out with you guys. Yeah, come back anytime. Thank you to both of you. You can hear more of Elsa on Consider This, NPR's afternoon podcast about what the news means for you.

And for more science stories, just like this one, follow Shortwave on whatever. you're listening to. This episode was produced by Jeffrey Pierre, Rachel Carlson, and Hannah Chin. It was edited by Christopher Inteliata and Rebecca Ramirez. Aruneyer checked the facts. Becky Brown and Robert Rodriguez were the audio engineers. I'm Emily Kwong. And I'm Nate Rot.

Thanks for listening to Shortwave. Later. Later, Gaitas. Peace.