Fungi Create Complex Supply Chains | A Rookie Robot Umpire Takes The Field

Fungal networks in the ground ferry crucial nutrients to plants. But how do brainless organisms form complex supply chain networks? Also, in this year’s baseball spring training, the new Automated Ball-Strike System is helping settle challenges to home plate pitch calls.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Speaker 00

  WNYC is supported by Bayer. Science is about asking questions, testing, trying again. It's not easy, but it's relentless. It evolves, and that's why science delivers. Learn more at sciencedelivers.com.

• 0:18Ira Flatow?

  This is Science Friday. I'm Ira Flatow.

• 0:20Flora Lichtman?

  And I'm Flora Lichtman. Today on the podcast, we'll take a look at how AI might be coming for baseball. But first, how does a brainless fungal thread make decisions?

• 0:31Speaker 03

  If that doesn't keep people up at night, I don't know what does.

• 0:38Flora Lichtman?

  As the leaves start to pop out, it is natural to look up and admire the trees. But actually, there's a lot of action happening underneath your feet. Beneath you is a complex network of fungal trade routes, carrying essential nutrients to the roots of plants mined from the soil by fungus. It is a subterranean supply chain. But how exactly do these complex networks form? How does the fungus decide where to ship which resources or where to build roads? Basically, how does a brainless thread make decisions? Here to help us leaf through these questions is Dr. Toby Kiers, professor of evolutionary biology at Free University in Amsterdam and executive

• 1:22Flora Lichtman?

  director of the Society for the Protection of Underground Networks. Toby, welcome to Science Friday.

• 1:28Speaker 03

  Such an honor to be here.

• 1:30Flora Lichtman?

  OK, I read a quote from you that said, this is the kind of research that keeps you up at night. Please tell me why fungal networks keep you awake.

• 1:40Speaker 03

  Well, we really wanted to understand the inner lives of these fungi. We studied a group of network-forming soil fungi, and these are known as mycorrhizal fungi. And they're really defined by their trading relationship with plants. And it's not just some plants, but it's 80% of all plant species form trade relationships with these mycorrhizal fungi. And you just have to think about what they do to create these trade infrastructures. They have to actually grow out into the soil and create this very complex network to collect the resources. But then they have to evaluate like where and when to transport those resources back to the root. And then they have to collect payoffs for those resources.

• 2:23Speaker 03

  So that's what I'm talking about, staying up late at night. How does an organism that has no central nervous system, no brain, how does it achieve that?

• 2:32Flora Lichtman?

  Well, OK, so take me underground. If I am standing, you know, on my lawn, in front of my garden or underneath a tree, what should I be imagining as happening beneath me?

• 2:44Speaker 03

  That is such an amazing question, because this is what we're trying to bring to light. So you can imagine a network growing, and it's a very complex network with lots of different junctions. And this network, it's sort of like an open tube, meaning that inside the network, there's this flow of nutrients. All of the cellular contents in the network is flowing through this open pipe tube.

• 3:08Flora Lichtman?

  What, wait, what's flowing? What are the things that are actually, what are the packages going back and forth?

• 3:13Speaker 03

  Well, all the cellular contents, so all of the mitochondria, the nuclei, but really the nutrients too. So the plants are feeding carbon to the fungi in the form of sugars and fats. And the fungi are collecting these through very intricate structures that actually penetrate into the root cell. So the carbon is flowing from the plant down into the network and has to go all the way to the growing tips to build more network. But the network is also, at the same time, foraging and collecting resources like phosphorus and nitrogen and water and bringing that back, all the way back to the plant root system. So if you think about these tubes, they actually have streams of nutrients moving in two directions simultaneously.

• 3:58Flora Lichtman?

  That sounds complicated, just physics wise.

• 4:01Speaker 03

  That's why we work with biophysicists, because this is something they had never seen before.

• 4:06Flora Lichtman?

  Really?

• 4:07Speaker 03

  And that's what's so exciting about it, is we really just have to visualize what they're doing, test different hypotheses and see how they react.

• 4:15Flora Lichtman?

  You built a robot to do some of this work. Tell me about the robot.

• 4:19Speaker 03

  So the robot is really cool. You know, all of this happens underground, as you said, out of sight. So it's nearly impossible to study. And that's why we built a robot. And then we started imaging the network with this robot 24 hours a day. And so the robot with this data, we could actually extract the physical topology of the network and give every junction in that network a unique number. Now, this is the crazy part. This allowed us to track about half a million of these nodes, of these fungal highways, at any given time. So we're keeping track of the physical coordinates of the network. But then we zoom in at specific coordinates to look at the traffic flows within these highways. And the traffic flows, that's what I mean by the nutrients, the carbon, the water,

• 5:04Speaker 03

  the phosphorus, all moving through that.

• 5:07Flora Lichtman?

  I mean, the videos are amazing that you produced with this robot.

• 5:11Speaker 03

  The videos were really exciting to make because I don't think people imagine just how dynamic these systems are underground. And when we show these videos of the nutrient flows, these are in real time. So these flows are actually moving very fast. And it's very dynamic. So not only are the two streams going in, let's say, anti-parallel directions, so two directions at the same time, but sometimes they switch directions. So a stream will be going very fast one direction, and all of a sudden it'll switch directions and start going the other way.

• 5:42Flora Lichtman?

  OK, I think this gets to one of the essential questions. Who's making the decisions? How does a brainless thread make a decision?

• 5:51Speaker 03

  Exactly. Like, if that doesn't keep people up at night, I don't know what does. And that's really where we're just starting on this journey of figuring out how it works. Mike or Isol fungi, what we started to learn through this work is that they use very simple local rules. These local rules allow them to prevent, let's say, overbuilding. And when I talk about a local rule, it's something as simple as when two roadways meet, they fuse, they physically connect those traffic flows of nutrients.

• 6:19Flora Lichtman?

  Every time they meet, they fuse.

• 6:21Speaker 03

  Exactly. Now, what's cool is that this actually confers two advantages. It removes dead-end streets, which are really bad for supply chains. But it also improves the traffic flows across the network, so really efficiently moving the resources to and from the route.

• 6:36Flora Lichtman?

  What was your biggest aha from these findings?

• 6:40Speaker 03

  Well, that's a good one. There were so many ahas during this project that I can't even begin to list them. I think for me, it was this idea that these organisms, they've been really shaped by natural selection for hundreds of millions of years. And to be able to physically observe these type of strategies is really incredible because like we use as humans, we use AI to solve very complex problems. And so it started making us think, well, what can we learn from these living algorithms that we're watching in real time?

• 7:12Flora Lichtman?

  Hmm, living algorithm. I like that. I mean, is it permanent carbon capture?

• 7:17Speaker 03

  So really, when we talk about carbon, no carbon is really permanent in that sense. So these fungi are important parts of the carbon cycle. But what we want to do is make a big enough sponge that they keep that carbon down under there for longer. And so, of course, the fungi are respiring, they're using the carbon, some of that is released. But the fungi also make these secondary compounds that are very hard to degrade. And so if the carbon goes into that form and really form these sticky substances that hold the soil together, then we can keep the carbon down underground longer.

• 7:52Flora Lichtman?

  Which of course is useful if you're trying to draw CO2 out of the air, right?

• 7:56Speaker 03

  Exactly. So this is like the physical infrastructure that allows us to bring the carbon below ground. I mean, in many ways, we think of these networks as really one of Earth's circulatory systems.

• 8:08Flora Lichtman?

  Okay, I'm gonna, I'm gonna take a chance here and wade into deep thoughts territory.

• 8:13Speaker 03

  I'm ready.

• 8:14Flora Lichtman?

  So you can bat it away if you want. You know, when you see these brainless tubes making decisions, and I know they're, they're following rules, they're not making decisions, but you know, does it make you think differently about sentience, or intelligence, or any of these sort of big squishy ideas?

• 8:35Speaker 03

  I'm vigorously nodding my head because what we see is that, you know, we're so, as a society, we are so concentrated on the brain as a way to process information. And I get goosebumps just thinking about other options for processing information and making decisions. And that's what we're seeing in real time is just how that can happen. And it really opens up, I think, a brand new field of research into how organisms without brains process information and how we can actually understand the strategies that they've evolved to solve complex problems.

• 9:14Flora Lichtman?

  You know, I want to ask you about something else that I think is related. I remember when research bubbled up years ago that suggested trees communicate and cooperate through these fungal networks. And some people called it the wood wide web. And there was a ton of interest and also pushback about it. How do you think about that? And does your research help us understand that any better?

• 9:43Speaker 03

  There's one really important issue to think about with what research has been done on trees and networks. And it's really always taken a very plant focused view. And that is, how do these plants, how are they using fungi to, let's say, talk or get resources? And what we're trying to do is actually turn that research on its head and ask a different question and say, what is in it for the fungi? What are the fungi doing? Where are they moving their resources?

• 10:11Flora Lichtman?

  The fungi eye view.

• 10:13Speaker 03

  Exactly. So we're really taking a fungal eye view. And so it's not that we're weighing in so much on the research about what's happening with trees and how they communicate, but we're really trying to understand from a fungal lens, why and how are they moving resources? And then if that happens to help the tree, it's fantastic. But first, we really have to understand that living infrastructure underground and how it grows and what benefits it as it grows.

• 10:40Flora Lichtman?

  Your team fungi is what I'm hearing.

• 10:42Speaker 03

  I'm totally team fungi.

• 10:44Flora Lichtman?

  Toby, thank you so much for taking the time to chat with us today.

• 10:47Speaker 03

  It was really fun. Thanks so much.

• 10:49Flora Lichtman?

  Dr. Toby Kiers is the Executive Director of the Society for the Protection of Underground Networks, and you can check out a video of these fungal highways in action at sciencefriday.com/fungus. You don't want to miss it. The videos are awesome. sciencefriday.com/fungus.

• 11:09Ira Flatow?

  After the break, are we entering the age of the robotic umpire?

• 11:14Speaker 04

  It is more accurate. There's no way for a human eye to be as good at this as a series of high-speed cameras.

• 11:27Speaker 00

  Science Friday is supported by PBS, presenting Going Wild. If you love learning about the natural world and meeting the scientists who help us understand it, be sure to check out the new season of Going Wild with Dr. Ray Win Grant. It's the chart-topping and Webby Award-winning podcast from the folks at Nature on PBS, now with a video companion series. In this season of Going Wild, host acclaimed wildlife ecologist Dr. Ray Win Grant heads out into the field to explore the animals, people, and stories that make nature worth saving. Stops include a hibernating black bear den in Arkansas and an underwater shipwreck site off the Florida coast. If you're looking for a place to start, check out the season's debut episode, where Ray joins beloved biologist and influencer Jordan King in the Florida Everglades to learn

• 12:11Speaker 00

  about his unlikely journey into science and how to study a wetland when it's not very, well, wet. So don't miss out. Follow Going Wild with Dr. Ray Win Grant on Apple Podcasts, Spotify, YouTube, or wherever you get your podcasts. WNYC is supported by Bayer. Every day in America, science delivers, not just in the headlines, but in the moments that matter most. Science is a journey, one of curiosity, persistence, and progress. It's about asking questions, testing, learning, and improving again and again. Science delivers harvests that feed families, tools that help farmers grow more with less, and new ways to protect land for generations to come. Let's keep asking, keep testing, keep discovering, so

• 12:55Speaker 00

  science can keep delivering. Learn more at sciencedelivers.com.

• 13:00Speaker 05

  Support for Science Friday comes from the Hyacinth Simons Foundation, unlocking knowledge, opportunity, and possibilities. More at hsfoundation.org.

• 13:20Ira Flatow?

  There is one certain sign that spring has sprung, and I'm talking baseball. If you listen to this show, you know how much I love baseball. And the geek in me loves to understand the science and the technology behind it because the beauty is in the details. I bring all of this up because in addition to the new rules in baseball, like the pitch clock, the ghost runner in extra innings, now comes another wrinkle, the AI umpire. In some spring training games, baseball has been testing a robotic system to verify calls made by the home place umpire. Was it a ball? Was it a strike?

• 14:01Ira Flatow?

  Well, here to explain the tech and how it might change the game is Davey Andrews, a musician and baseball writer. He's contributing writer for Fangraphs. Welcome to Science Friday.

• 14:12Speaker 04

  Thank you very much for having me, Ira.

• 14:13Ira Flatow?

  Let's talk about explaining this. How does the system work? It doesn't call every pitch, does it?

• 14:19Speaker 04

  No, although they have tested that in AAA. And right now, it's a challenge system that uses Hawkeye cameras, which are the same technology that's used to challenge line calls in tennis. When a batter, or a catcher, or a pitcher disagrees with the umpire's call, they have the chance to tap their head, which has become the signal, and they quickly check to see if the ball hit the strike zone according to those Statcast Hawkeye cameras.

• 14:46Ira Flatow?

  Yeah, I've watched some of the spring training games, and what happens is there is a white computer-generated strike zone put up on the screen, and you look to see whether the ball touches the white area or not, just like it touches the line in tennis or not, right?

• 15:02Speaker 04

  Exactly.

• 15:03Ira Flatow?

  And the thing I have about it that bothers me is that this strike zone is two dimensional, but the real strike zone is three dimensional, right?

• 15:10Speaker 04

  Absolutely. The rulebook strike zone, which is the one even now in spring training that umpires are calling, is the area over home plate, which is pentagonal. And it's between the player's knees and the midpoint between their belt and their armpits. And so it's a pentagonal prism. It's a volume as opposed to just a two dimensional rectangle, like you said. So there's a little disconnect here.

• 15:36Ira Flatow?

  Does this get in the way of calling balls and strikes?

• 15:39Speaker 04

  I mean, the answer is yes and no. So they have tried, previous iterations were three dimensional, and they found that the strike zone was a little too big. And, you know, sometimes there are pitches that, you know, every pitch drops on its way to home plate because of gravity, and many of them also because of the spin that the pitcher imparts onto the ball. And so there are ways for the pitch to dip and touch the back of home plate, or maybe the front of home plate, or the sides, but to exit the strike zone before it hits that one rectangle, which is located right in the middle of the plate.

• 16:11Ira Flatow?

  Right.

• 16:12Speaker 04

  So technically, the umpires and the robots are calling two completely different zones. They just overlap a great deal.

• 16:19Ira Flatow?

  Oh, is that right?

• 16:20Speaker 04

  Well, so the rulebook zone, like I said, is knees and the midpoint between belt and armpit. The robots are doing it, it's a percentage of the player's height. So it's actually just over a quarter of their height. It's no longer, you know, your knees or your shoulders or anything like that. All the players in AAA last year, hundreds of players shrank by several inches.

• 16:42Ira Flatow?

  You mean, they leaned over to make their strike zone smaller?

• 16:45Speaker 04

  You can't do that anymore. I'm sure people remember Ricky Henderson or Pete Rose were crouched like into a ball, basically, to give themselves the smallest possible strike zone. The robo-zone doesn't appreciate that. So in the minors last year, hundreds of players magically got much shorter because they didn't want to be charged for a bigger strike zone when they didn't actually have one.

• 17:06Ira Flatow?

  Oh, that is funny. A lot of purists are not going to like this.

• 17:09Speaker 04

  Absolutely.

• 17:10Ira Flatow?

  Is there a lot of talk, a lot of disagreement about it being accepted?

• 17:14Speaker 04

  I think there are places where even if you're not necessarily a hardcore purist, there are parts to argue with. There are certain players who don't like it. And the reason I ended up writing about it is because Max Scherzer, who is a very respected player and a Hall of Famer, or will be a Hall of Famer five years after he retires, he brought it up and he made a very real point that, you know, we're humans and maybe it just makes sense to be judged by humans. That said, the challenge system has gone over remarkably well because it's quick and it's accurate. It seems fair and it doesn't cut out a lot of the things that people like. The thing that I worry about is that there's a huge value in framing for a catcher and catching the ball in such a way that you make a ball look like a strike.

• 17:59Ira Flatow?

  Right.

• 17:59Speaker 04

  Or you just keep a ball that is a strike from appearing like a ball. It's not necessarily fooling the umpire, but it's a very important part of catcher's job and it's a very important part of the game traditionally. And if they were just to switch over to a full automatic zone, that would disappear and catcher's job wouldn't really matter anymore. And that seems a lot less fun to me.

• 18:19Ira Flatow?

  Yeah, we've had challenges, you know, where you can challenge ruling on the field and then they have to go away, the ups huddle, they get their headsets on. How is this different than that?

• 18:29Speaker 04

  Well, so this is different because, you know, it's done all by cameras. It's technology making this decision. And then according to Hawkeye's press releases, it's accurate down to like just over two millimeters. So it's not perfect. And I would ask people to keep in mind that normal umpires, according to MLB's data, get the call right 93% of the time. And even on balls that are close to the edges of the zone within one baseball's width, they're still right 82% of the time. So they're already very, very good. But this is a little more impartial and objective and it is more accurate.

• 19:10Speaker 04

  There's no way for a human eye to be as good at this as a series of high-speed cameras.

• 19:16Ira Flatow?

  How soon do you think until we see it every day?

• 19:18Speaker 04

  I mean, it's not going to happen this season. I think it's possible that it will be as early as next season. I think it's more likely that the collective bargaining agreement is up after the 2026 season. So I suspect that it will be rolled in once in the 2027 season after all those changes happen.

• 19:37Ira Flatow?

  Well, I'm, as a baseball fanatic, I'm very much in favor of this because, you know, especially in critical areas and critical times, critical pitchers in the game, right? You want to be able to get it right.

• 19:48Speaker 04

  Sure. Well, I know, I was told that you're a Mets fan.

• 19:51Ira Flatow?

  Yes.

• 19:52Speaker 04

  And I'm sorry, I actually just have an article coming out. Your catcher, Francisco Alvarez, who just went down with an injury, but he is an excellent framer. And so if you're hoping that the Mets do well, once they get him back, he's the kind of guy who would make you not want a robo zone because he is good at making pitches look like strikes and getting those borderline calls.

• 20:12Ira Flatow?

  Well, thanks a lot again for putting another stab into my Mets fandom, like everyone else does. Thank you, Davey, for taking time to be with us today and good luck in your writing.

• 20:24Speaker 04

  It was my pleasure. Thank you very much, Ira.

• 20:25Ira Flatow?

  Davey Andrews is a musician and baseball writer, a contributing writer for Fangraphs. He's based in Brooklyn.

• 20:34Ira Flatow?

  That's about all the time we have for now. A lot of people helped make this show happen. John Dancoski. Annie Nero.

• 20:42Speaker 05

  Jason Rosenberg. Rasha Ridi.

• 20:45Ira Flatow?

  I'm Ira Flatow. Thanks for listening.