SACHA PFEIFFER, HOST:
It's time now for our regular science news roundup with our friends at NPR's Short Wave podcast, Regina Barber and Rachel Carlson. Hi to both of you.
REGINA BARBER, BYLINE: Hey, Sacha.
RACHEL CARLSON, BYLINE: Hey, Sacha.
PFEIFFER: So how this works is you've brought us three science stories that caught your attention this week. What are they this week?
BARBER: The invasive Joro spider spreading across the East Coast...
CARLSON: ...A fungus that's turning cicadas into sexed-up zombies...
BARBER: ...And a new atlas on what spaceflight does to the human body.
PFEIFFER: Ok. All right. So the spiders - now, you might think I'm scared to hear about this, but I'm in the camp that spiders are our friends.
CARLSON: OK.
PFEIFFER: So tell us about...
BARBER: Great.
PFEIFFER: ...These invasive spiders apparently making homes around the East coast.
BARBER: Yeah. So I'm going to tell everyone that, yeah, let's not worry about these Joro spiders. They're not dangerous. They do have these, like, really big webs. The females do have inch-long bodies, and the legs make them up to almost 4 inches long. Well, OK, and they're black, and they're electric yellow, and they're venomous.
PFEIFFER: Now we see why people don't like spiders so much.
CARLSON: Not helping so much, Gina. Let me give this a try. So Joro spiders rarely bite, and even if they did, their fangs are super small. They'd have a really hard time even getting through your skin. And if they did bite you, it's easily treated just like a normal bug bite and even less painful than a beesting.
PFEIFFER: Again, spiders not so bad, right?
BARBER: Exactly.
CARLSON: Yeah.
PFEIFFER: How did these spiders get here?
BARBER: So they most likely got here through shipping containers from East Asia, and now they have this big population in Atlanta. And it's a big port of entry, so that makes sense. And it's also - like, has a similar humidity and temperature to their natural habitat in Asia.
CARLSON: And the spiders can die if it gets too cold, so with climate change warming our planet, researchers think that warmer winters are going to help Joros establish populations in more places farther north.
PFEIFFER: You mentioned that these spiders are invasive, and obviously, oftentimes, invasive species can be very bad for ecosystems. Do we know if this is going to be bad for the East Coast in any way?
BARBER: We actually don't know yet. There needs to be more research on how Joro spiders are affecting their environment and other native species. But one of the researchers I talked to said that spiders are a prime example of two trends that are helping a lot of other invasive species spread, and that's global shipping routes expanding and a warmer climate.
CARLSON: And, Sacha, we can all help researchers by tracking Joros. So if you see one, you can log it on community sites like iNaturalist, Project Joro or Joro Watch.
PFEIFFER: They have their own websites, wow.
CARLSON: Yep.
PFEIFFER: OK. So your next story keeps us on the critter beat. It's about a fungus that is turning cicadas into what you described as sexed-up zombies?
BARBER: Yes. Yes. So you've probably heard about this huge cicada phenomenon happening this year, right?
PFEIFFER: I have, yeah.
BARBER: OK. So, yeah. So there's these two groups of periodical cicadas, and they're emerging at the same time. One comes out every 17 years in the Midwest, and the other emerges every 13 years in the Midwest and the Southeast.
PFEIFFER: And where does the zombification come in?
CARLSON: OK, yeah. So our colleague Rachel Treisman recently reported on this. It's the fungal parasite Massospora cicadina, which has been observed in these cicadas in about half a dozen states now. It fills an infected cicada's abdomen and then emerges out of its back end like this chalky white gum drop. Or at least that's how Matt Kasson described it. He's a fungi scientist.
PFEIFFER: I have never liked gum drops. Now I definitely never will eat gum drop.
CARLSON: Absolutely not.
BARBER: Yeah, it's a horrible visual. OK, so Matt told NPR that this fungus is unique because it keeps the cicada alive even after a third of its body has been replaced by this fungal tissue. And it's not just alive. It makes the cicadas hypersexual in an attempt to spread its spores.
PFEIFFER: Ah. So is it kind of like the fungus hijacking the cicadas for their own gain, and then the zombified cicadas spread the fungus even farther?
CARLSON: Yeah, that's exactly it. So infected male cicadas will try to mate with healthy females and then also other males. And they're really just flying around and raining down spores like flying salt shakers of death. That's how Matt put it.
PFEIFFER: This guy is good at phrases.
BARBER: Yeah.
CARLSON: I know. He has some really good language. And if that weren't enough, Matt says this fungus produces a stimulant that likely means all of these cicadas are high out of their minds while this is all going down.
PFEIFFER: Is it known how widespread this fungus is in the cicadas?
BARBER: So Matt says the incidence of infection is pretty low, maybe below 5%, although he's encountered some areas where it's as high as 20- to 30%. And if you happen to come across one yourself, don't worry. This fungus is specialized to cicadas, according to scientists at Chicago's Field Museum of Natural History. So safe to handle, but you might want to wash your hands after that.
PFEIFFER: A good rule for life in general.
BARBER: Yes.
PFEIFFER: Last topic - totally different. This one's really interesting. I saw an article about this just today - understanding how spaceflight affects human health.
CARLSON: Yeah. OK, so as we know, humans have evolved to thrive here on Earth, which means spaceflight and microgravity are, to put it simply, rough on the body. We've known that astronauts lose bone density in space. Blood and bodily fluids are redistributed in microgravity, which really just means that without the effects of Earth's gravity, these things are all pushed upwards from the legs and abdomen to the heart and the head.
BARBER: But we haven't known much about what's happening inside human cells during spaceflight. And as spaceflight becomes more common and astronauts set out on longer missions, this other piece of the puzzle is crucial.
PFEIFFER: And are these new findings getting at that, about what happens at the cellular level in space?
CARLSON: Yeah, so that's the goal because right now we don't know that much. But a huge collection of papers released this week in Nature and its companion journals is starting to fill in some gaps about what's going on inside cells. I talked to one researcher, Eliah Overbey, who told me about this one finding - telomeres, or markers of aging at the ends of chromosomes, seem to get longer during spaceflight as opposed to generally getting shorter like they do here on Earth.
PFEIFFER: And if telomeres get longer, do we know if that's a bad thing?
CARLSON: OK, yeah. So Eliah said we don't really know the implications of this yet, which is kind of the whole problem. But she does hope that a new database, the Space Omics and Medical Atlas, is going to help answer this question. It's the largest of its kind to date and includes data from a bunch of different space missions.
BARBER: Yeah, astronauts gave samples of things like blood, saliva and even skin biopsies before spaceflight, and then researchers compared those samples to ones taken after they returned to Earth.
PFEIFFER: Is the idea that now that we have more data, we'll be able to take better care of astronauts?
CARLSON: Yeah. Both Eliah and a space physician I talked to, Emmanuel Urquieta, talked about personalized medicine. And Eliah said the SOMA database helps us get closer to that kind of care for individual astronauts and for civilians who are interested in things like commercial space travel.
ELIAH OVERBY: Instead of, you know, it being a shot in the dark, a completely exploratory exercise and figuring out what's going on in the human body, they now have something to point them towards for novel scientific questions that they didn't have before.
BARBER: Right now, they only have that data for a small number of people, but Emmanuel and Eliah both say data like this will help usher us into a new era of space exploration.
PFEIFFER: Interesting. That is Regina Barber and Rachel Carlson from NPR's science podcast Short Wave. Every Tuesday this summer, you can hear their Space Camp series, looking at all things outer space, including what it's like for astronauts to live out there. Thanks to both of you.
CARLSON: Thank you.
BARBER: Thanks, Sacha. Transcript provided by NPR, Copyright NPR.
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