How did these flowers evolve to survive a megadrought?

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 https://www.science.org/doi/10.1126/science.adu0995, 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 [email protected] mailto:[email protected]. Listen 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 http://plus.npr.org/shortwave. Listen to Short Wave on Spotify https://n.pr/3HOQKeK and Apple Podcasts https://n.pr/3WA9vqh. 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 https://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 https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:00Speaker 00

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• 0:15Speaker 01

  You're listening to Short Wave from NPR.

• 0:20Emily Kwong?

  Hey, Shortwavers. Emily Kwong here.

• 0:22Speaker 03

  And Nate Roth, hello.

• 0:24Emily Kwong?

  Hello. And today, we have our biweekly Science News roundup, featuring the hosts of All Things Considered. And here with us is the glorious Elsa Chang.

• 0:32Speaker 01

  Hi, hi, hi. OK, I hear we're going to be talking about the social lives of sharks.

• 0:37Emily Kwong?

  Yes, and we have another story about a rapidly evolving wildflower.

• 0:41Speaker 03

  And another that looks at a, let's call it, counterintuitive grooming behavior in birds.

• 0:46Emily Kwong?

  All that on this episode of Short Wave, the science podcast from NPR.

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  Stay tuned for the following announcements and messages from our sponsors. This message comes from Capella University. You know that feeling when there's a spark building inside you, that you were meant for more? That's your own drive, pushing you towards what's next. Capella University gets that. With their FlexPath learning format, you can set the pace and earn your degree without putting life on pause. You've built experience and know what you're capable of. Now, this is your time to turn that momentum into more. The only real question is, what can't you do? Learn more at capella.edu.

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• 2:00Speaker 01

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• 2:15Emily Kwong?

  Okay, Elsa, which story do you want to start with?

• 2:17Speaker 01

  Oh, well, I want to start with the wildflowers.

• 2:20Emily Kwong?

  Lovely.

• 2:21Speaker 03

  Good choice.

• 2:22Emily Kwong?

  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.

• 2:30Speaker 01

  That's amazing.

• 2:31Speaker 05

  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.

• 2:41Emily Kwong?

  Plant biologist Daniel Anstett 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 mega drought.

• 2:54Speaker 01

  Wow.

• 2:54Emily Kwong?

  Yeah, this wildflower mystery is the focus of a new paper in the journal Science.

• 2:58Speaker 01

  Wait, so what are the monkey flower's secrets to survival?

• 3:03Speaker 03

  Well, Elsa, 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.

• 3:14Speaker 01

  So cool. Okay, so which traits did these surviving flowers have?

• 3:18Emily Kwong?

  Yeah, the scientists found that three of the populations that recovered the best adapted their stomata to open less.

• 3:25Speaker 01

  Stomata?

• 3:25Emily Kwong?

  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 survives.

• 3:36Speaker 01

  Slow and steady. How did the scientists even figure this out?

• 3:40Speaker 03

  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.

• 3:52Emily Kwong?

  And Daniel hopes this work will continue for decades, just like the long-term studies on Charles Darwin's famous finches in the Galapagos.

• 3:59Speaker 05

  That's what we hope to build with this study, is this long-term study. Because, yes, rapid evolution happened. Great, those populations did good in one time point. But what are the longer-decado consequences?

• 4:13Speaker 03

  Like, so what if an insect comes along? Or there's a prolonged period of rain? Will the survivors have enough genetic variation within them to respond again? That's kind of the role of the dice that evolution brings, and this is the kind of science that shows how it all goes down.

• 4:26Speaker 01

  Fascinating. But I am still processing how a flower can look like a grinning monkey. Anyway, next topic. Bathing birds? Tell me more.

• 4:35Speaker 03

  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 was like a thing.

• 4:45Speaker 01

  Me neither. Sounds like a great spa treatment. Go ahead, Emily.

• 4:48Emily Kwong?

  I did it this morning. I highly recommend. No, dust bathing ostriches do it, some species of songbirds, turkeys and chickens. Patricia Yang, an assistant professor at National Singhua University in Taiwan, says a bath for a chicken involves dirt and sand.

• 5:03Speaker 01

  Ouch.

• 5:04Speaker 06

  And the chickens start like digging themselves into the mud and start like wiggling their wings and then put the sand on them.

• 5:13Speaker 01

  Sand does not sound comfortable to me at all.

• 5:17Speaker 03

  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.

• 5:31Emily Kwong?

  Tiny little bugs like feather mites, which can burrow into a bird's plumage and cause itching, scabbing, anemia and all sorts of other bad things.

• 5:39Speaker 01

  Wait, but how does taking a dirt or sand bath help a bird get rid of all those gross parasites and bugs?

• 5:47Speaker 03

  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 then a bunch of mite-covered chicken feathers from a farm on Taiwan.

• 6:01Emily Kwong?

  And then they vibrated those feathers in the sand at a rate of 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.

• 6:13Speaker 01

  I wonder if this would work with humans who have lice.

• 6:16Speaker 03

  You're welcome to try it out.

• 6:18Speaker 01

  In a sandbox. Give me some sand, the next time I get infested, guys.

• 6:22Speaker 03

  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.

• 6:58Speaker 01

  Wow. Okay, now for our final topic, sharks?

• 7:03Speaker 03

  That is correct. And as a surfer, this paper totally caught my eye because bull sharks have friends.

• 7:09Speaker 01

  Oh, wait, what's a bull shark again?

• 7:11Emily Kwong?

  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, um, they, yeah, they're really social and they like hanging out with each other.

• 7:26Speaker 01

  Wait, they're like friendly?

• 7:27Emily Kwong?

  Mm-hmm.

• 7:28Speaker 01

  They're like gregarious sharks.

• 7:30Emily Kwong?

  Well, what the paper is saying is basically individual sharks seem to have a distinct preference for some sharks over others.

• 7:38Speaker 01

  Ooh.

• 7:38Emily Kwong?

  Yeah, Natasha Marosi 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 observed sharks by tagging them and through video recordings of dives.

• 7:52Speaker 03

  And get this also, Natasha can actually tell who's who just by like looking at their wounds or scars and...

• 7:57Speaker 00

  Sometimes just by the way they swim.

• 8:00Speaker 03

  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.

• 8:09Speaker 00

  Chunky and Mogul and Sharkbite were like the boys' club.

• 8:14Speaker 01

  Junkie Mokel and Shark Bite the Voice 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?

• 8:25Speaker 03

  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.

• 8:38Emily Kwong?

  Yeah, and the team found that a shark's age made a difference in who they associated with. Middle-aged bull sharks tended to be at the center of social networks with more connections than younger or older sharks.

• 8:48Speaker 01

  Interesting.

• 8:49Speaker 03

  Yeah, and a shark researcher who didn't work on this paper, Catherine McDonald, also cautioned against too many comparisons to human friendships, 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."

• 9:08Speaker 01

  Nice.

• 9:10Emily Kwong?

  Elsa, so fun to have you on.

• 9:13Speaker 01

  So fun. I love hanging out with you guys.

• 9:15Speaker 03

  Yeah, come back anytime.

• 9:16Speaker 01

  Thank you to both of you.

• 9:18Emily Kwong?

  You can hear more of Elsa on Consider This, NPR's afternoon podcast about what the news means for you.

• 9:25Speaker 03

  And for more science stories just like this one, follow Short Wave on whatever app you're listening to.

• 9:30Emily Kwong?

  This episode was produced by Jeffrey Pierre, Rachel Carlson, and Hannah Chin. It was edited by Christopher Intagliata and Rebecca Ramirez. Arun Iyer checked the facts.

• 9:39Speaker 03

  Becky Brown and Robert Rodriguez were the audio engineers.

• 9:42Emily Kwong?

  I'm Emily Kwong.

• 9:43Speaker 03

  And I'm Nate Roth.

• 9:44Speaker 01

  Thanks for listening to Short Wave. Later.

• 9:46Emily Kwong?

  Later, gators.

• 9:47Speaker 03

  Peace.

• 9:52Speaker 04

  Stay tuned for the following announcements and messages from our sponsors. This message comes from Capella University. You know that feeling when there's a spark building inside you, that you were meant for more? That's your own drive, pushing you towards what's next. Capella University gets that. With their FlexPath learning format, you can set the pace and earn your degree without putting life on pause. You've built experience and know what you're capable of. Now, this is your time to turn that momentum into more. The only real question is, what can't you do? Learn more at capella.edu. This message comes from Mint Mobile. Ditch overpriced wireless and get premium wireless for less.

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