SCOTT DETROW, HOST:
It's time now for our science news round up from Short Wave, NPR's science podcast. I am joined by the show's hosts, Regina Barber and Nate Rott. Hey to both of you.
REGINA BARBER, BYLINE: Hey.
NATE ROTT, BYLINE: Hello.
DETROW: Nate, that's the first time I've introduced you that way. That's exciting.
ROTT: Yeah, man. It's going to be fun - doing it till the end of October.
DETROW: All right. So as always - Regina, you know how it works.
BARBER: I do.
DETROW: You have brought us three science stories that caught your attention recently. I assume at least one is about space. Tell me what they are.
BARBER: There is one about space. But the first story is about how many different types of insects there are on the planet. And spoiler alert, it may be way more than you thought.
DETROW: Ooh, OK.
ROTT: Our second story is about space, Scott, and it looks at quasars, which are these super bright lights from ancient galaxies that can tell us more about the formation of the universe.
BARBER: And the final study looks at the unfortunate eating habits of California wolves.
DETROW: Let's start with the insects, the many, many, many insects.
ROTT: Yes, bugs - so this study starts in a protected area in Costa Rica, and it looks at a very specific subset of insects called parasitoid wasps.
MELISSA GUZMAN: And they're really diverse. There are these, like, tiny wasps, like, really, really tiny.
BARBER: Like millimeters tiny, says Melissa Guzman, an entomologist at Cornell University.
ROTT: And these itty-bitty wasps are called parasitoids because they lay their eggs in or on other species, like caterpillars.
DETROW: Can I say something? I saw a wasp do this to a cicada in my backyard, and it was horrifying.
ROTT: What?
DETROW: It was like "Alien" in real life. It was like - it was...
BARBER: Oh, my gosh.
DETROW: It blew my mind.
ROTT: Life finds a way.
BARBER: But don't worry. These are not hatching out of human chests.
DETROW: Good. OK, OK.
BARBER: It's going to be OK.
DETROW: OK.
ROTT: Yeah, yeah, for now - but because these wasps are so small, it's, like, really hard to tell one species from another. So the scientists looked at a specific sequence of DNA from these wasps, and using that and some fancy modeling, they estimated there are 3,400 different species of one subfamily of parasitoid wasps in this one nature reserve.
DETROW: What?
ROTT: A lot.
BARBER: Yes, a lot - but scientists wanted to take it a step further to get a sense of how many types of all insects there were in the reserve in Costa Rica. So they used that modeling and a larger sample of insects to get a number.
ROTT: And then they used that number to try to solve this big scientific mystery, Scott.
DETROW: I love myself a good big scientific mystery. Which one was this?
BARBER: So scientists wanted to know how many species of insects existed on the entire planet. And the best estimate to this point, based on studies of beetles, is that there are roughly 6 million.
ROTT: And for perspective, Scott, even the most generous estimates of how many bird species there are on the planet suggest only about 20,000.
DETROW: OK, so it's more than 6 million, I'm assuming is where this is heading.
(LAUGHTER)
ROTT: Yes. So this new study published in the Proceedings of the National Academy of Sciences suggests that that 6 million number - you are right, Scott - is a huge undercount.
DETROW: How many insect species are there on Earth?
BARBER: Yeah, between 14 and 20 million at minimum, so up to three times as many species as previously believed. Here's Melissa again.
GUZMAN: There's so much that we don't know, right? And I think it's humbling just to get a sense of how much we have yet to discover.
DETROW: That's wild. Like, but what do you do next?
BARBER: Yeah.
DETROW: Do you have, like, an insect census? How do you try and verify this in any way?
ROTT: I mean, yes, there's a lot of uncertainty with this kind of modeling. And, you know, we've only taxonomically described about 1 million insects so far. So, you know, do the math. It would take a lot, a lot, a lot of work.
DETROW: OK, next topic - quasars, fun word to say, cool thing - remind us what they are.
BARBER: Yeah, so they are blazing bright centers of galaxies, and at the center of that is a supermassive black hole, millions of billions of times the mass of our sun, and dust and gas is spiraling into that black hole. It heats up, and it starts to glow. So when astronomers see these quasars, the light that they see is...
DAMING YANG: A supermassive black hole caught in the act of feeding.
DETROW: What an amazing thing to think about.
BARBER: Yeah, so that's Daming Yang. He's the first author of the study out this week in the Journal of Astronomy and Astrophysics (ph), which reports the discovery of 31 quasars. And these are among the oldest quasars ever found. And before this study, astronomers only knew a handful of quasars this old.
ROTT: Yeah. And, Scott, something that's kind of cool about this is that these were all found with a space telescope that not a lot of people know exist. It's called Euclid. The European Space Agency launched it in 2023, and although it isn't as powerful as the Hubble Space Telescope or James Webb, it was designed to scan large swaths of the sky, which makes it really awesome at finding rare objects.
DETROW: I mean, this is a cool thing to think about and envision. But I assume astronomers need a little more than this is cool for doing this work. Like, what is the practical value...
ROTT: (Laughter).
BARBER: Yeah.
DETROW: ...Of spending time trying to ID these?
BARBER: Yeah, so these quasars are from, like, soon after the big bang. They're much bigger and brighter than astronomers would expect them to be that early in the universe. So Daming says there's a lot of questions about how they got so big so fast.
YANG: Like, what are they grown from? How did they grow? Like, these questions - by only collecting more of these quasars, we can answer this.
ROTT: And these ancient quasars might tell scientists more of the era when stars were born from the primordial hot goo that occurred after the big bang.
DETROW: We will save the primordial hot goo for another day.
ROTT: (Laughter) Fair, fair (ph).
BARBER: Yes.
DETROW: And let's move on to topic three, wolves.
ROTT: Yes, an animal that is often controversial...
BARBER: Yeah.
ROTT: ...Wherever it is cohabitating with people, you know, whether that's in the western U.S., where I am, the Midwest or Europe, you name it.
BARBER: Yeah, and a new study out this week in the journal PLOS One is not going to soothe any of that hate some people feel about this predator.
DETROW: Why is that?
ROTT: So this study's focus is specifically on wolves in California, which have migrated here from Oregon. And it looks at the impact they're having on cattle and, consequentially, people, ranchers.
BARBER: Yeah, and researchers at UC Davis did a DNA analysis of the scat - you know, their poop - from two wolf packs in 2022 and 2023 to see what they were eating.
ROTT: In both years, Scott, they found that the primary food source for these packs was cattle.
DETROW: I mean, I guess my reaction, I'm not super surprised by that - right? - because that's the particular reason that ranchers have such stark feelings about wolves. Like, what am I missing?
BARBER: That's reasonable to think, but it's uncommon for livestock to be the primary food for these wolves. So Tina Saitone, the study's lead author, says in most states, wolves predominantly eat wild game.
TINA SAITONE: But when wolves come to a human-dominated landscape like California with very little prey, you're going to see a very different composition of prey.
ROTT: So in other words, you know, California doesn't have big populations of elk like Montana or Wyoming. We don't have as many deer as there are in the Midwest or the northwest.
DETROW: So the wolves just don't have a choice then. Is that it?
BARBER: Yeah, that's right. So Neil Carter, who studies wolves at the University of Michigan, says this study, which he wasn't involved with, underscores how complicated it is for carnivores to come back to places that have fundamentally changed.
NEIL CARTER: If you want to have these animals on the landscape, you know, you have to start kind of building back the full ecosystem.
ROTT: Which in California would mean boosting mule deer populations, which are currently declining because of habitat loss, boosting other game species like elk that the wolves can eat. And look, that's not something that could happen overnight, but I think this study does give the people that manage wildlife and want to see fewer conflicts between wolves and humans something to think about and to aim for.
DETROW: Nate Rott and Regina Barber from NPR's science podcast Short Wave - thanks as always.
BARBER: Thank you.
DETROW: Yeah, thank you.
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