Speaker 1: Welcome to Stuff to Blow your Mind from how Stuff
Speaker 1: Works dot com. Hey you welcome to Stuff to Blow
Speaker 1: your Mind. My name is Robert Lamb and my name
Speaker 1: is Julie Douglas, and we are rounding up the Trilogy
Speaker 1: of Slime. Here we have. We started off with an
Speaker 1: episode tital Trilogy of Slime, where we talking about the
Speaker 1: natures of the nature of slime and organisms and all
Speaker 1: the important roles that it serves. Then we did a
Speaker 1: little Valentine special about the sex life of slugs, which
Speaker 1: is also very slimy but also a little stabby. And
Speaker 1: then finally we are discussing the slime mold, which is uh,
Speaker 1: taking it in a in a different direction, but a
Speaker 1: really really deceptively mind blowing direction, because when you just
Speaker 1: talk about the word mold itself is kind of boring.
Speaker 1: Mold is something that grows somewhere that you don't think about,
Speaker 1: you know, It's like it's it's that's the stuff that
Speaker 1: grows in the tub, it grows in the corner, grows
Speaker 1: under the house maybe and unless you think about it
Speaker 1: the better. Yeah. Um, but slime mold is actually something
Speaker 1: that is helping is to redefine intelligence and we'll talk
Speaker 1: a bit more about that in a moment. Um. But
Speaker 1: when we talk about slime mold and we say mold,
Speaker 1: we actually are not talking about any sort of fungus here, right,
Speaker 1: We're talking about mainly when we talk about slime old
Speaker 1: is something called phi serum polycephalum, and that that name
Speaker 1: actually means many headed slime mold. Slime is not a
Speaker 1: slime mold is not a plant or an animal. It's
Speaker 1: not a fungus, though it sometimes resembles one structurally. Yeah,
Speaker 1: it's a single, single celled creature, brainless, brainless, No, no
Speaker 1: brain and that's important here, no nervous system to speak of.
Speaker 1: And yet it's intelligence. It's what fascinates us. Yeah, I
Speaker 1: mean it ultimately makes us really think hard and deep
Speaker 1: about what intelligence is and what it can be, especially
Speaker 1: when we're trying to think about what what life could
Speaker 1: be like elsewhere in the in the universe. Um. And
Speaker 1: when you say in the universe, you should consider that, Uh,
Speaker 1: these guys go back in evolutionary history history about a
Speaker 1: billion years. And according to Dr Baldolph, who is a
Speaker 1: Swedish biologist studying the DNA of slime mold species, she
Speaker 1: says that they might be tightly linked to the development
Speaker 1: of soil on land, which is very cool to think
Speaker 1: about when you think about slime mold. Yeah, it's kind
Speaker 1: of triggy to to to really look at our history
Speaker 1: of fly mold because it's not something that really lends
Speaker 1: itself well to the fossil record. Yeah, exactly. We do
Speaker 1: know that there are nine hundred known species of slime mold,
Speaker 1: but they're really only about two that are studied in earnest.
Speaker 1: Slime mold's live in moist terrestrial habitats like decaying wood
Speaker 1: or fresh captung nice and once the mold has found food,
Speaker 1: such as a piece of decaying vegetation or a micro organism,
Speaker 1: it grows over it and it secretes digestive enzymes. So
Speaker 1: something like polycephalum then construct an elaborate network of interconnections
Speaker 1: between foods sources which allow it to shuttle nutrients around
Speaker 1: and get the full form of the organism fully fed. Um.
Speaker 1: Slime molds then devour many parts of bacteria, and then
Speaker 1: this releases those nutrients for other organisms to grow on.
Speaker 1: So it's a huge part of the ecosystem. So what
Speaker 1: does it look like, Um, it does not really so
Speaker 1: much look like slime per se like, it doesn't look
Speaker 1: like Nickelodeon bucket of slime falling on someone's head. And
Speaker 1: it has more of a yellowy consistency to it. It It
Speaker 1: doesn't particularly look viscous. Yeah, a lot of people have
Speaker 1: lined it to dog vomit. Um. That's a that's the
Speaker 1: usual thing that people spot. UM. But it actually comes
Speaker 1: in nearly every color of the rainbow except green because
Speaker 1: it lacks chlorophyll um. Some resemble honeycomb lattice structures, others
Speaker 1: kind of look like BlackBerry configurations. UM. And then of
Speaker 1: course there's the dog vomit, which is the classic thing. UM.
Speaker 1: Some remain microscopic to the eye, but others grow large,
Speaker 1: and you can form boldest masses as long as ten
Speaker 1: to thirteen feet long. So in the second we're gonna
Speaker 1: we're gonna get into the idea of what happens when
Speaker 1: you put slimold in a maze. But but imagine you
Speaker 1: have a slime mold working its way down a corridor
Speaker 1: and what happens when it encounters another slime mold coming
Speaker 1: down the corridor from the opposite direction. You probably want
Speaker 1: to do they do they fight each other? Do they
Speaker 1: is there a war of slime mold that takes place here? Well,
Speaker 1: if food is scarce is what's interesting is they do
Speaker 1: essentially team up into it like a single communicating mass. Yeah,
Speaker 1: it's really cool. Um. This is from a New York
Speaker 1: Times article, Can answers to evolution be found in slime mold? Yeah?
Speaker 1: The organisms do respond to starvation by rushing together by
Speaker 1: the thousands into a single blob. And the blob stretches
Speaker 1: out into a slug shaped mass about one millimeter long,
Speaker 1: which is about one inch, and then it begins to
Speaker 1: crawl along like a worm toward light. Wow, like like
Speaker 1: a caravan of line. Really yep yep. And then once
Speaker 1: it reaches the surface surface of the soil, the slug,
Speaker 1: this the slug configuration undergoes another transformation. Some of the
Speaker 1: cells turn into a stiff stock, while the others crawl
Speaker 1: to the top inform a sticky ball of spores and
Speaker 1: they stick to the foot of an animal and travel
Speaker 1: to a hospitable place. So inside the slug. And this
Speaker 1: again is according to the article, about one percent of
Speaker 1: the miba's turn into police. This is really cool. They
Speaker 1: crawl through the slug in search of infectious bacteria and
Speaker 1: then they vanquish it. Really, they find this pathogen and
Speaker 1: they devour it. And then these sentinels drop away from
Speaker 1: this slug configuration of slime mold, taking the pathogen with it,
Speaker 1: and then they die of the infection, while the slug
Speaker 1: itself remains healthy, the colony of it remains healthy. So um,
Speaker 1: this is so amazing to me. This is all going
Speaker 1: on at this microscopic level. This these acts of altruism. Really. Yeah,
Speaker 1: all right, we're gonna take a quick break and when
Speaker 1: we come back, we will enter the maze with the
Speaker 1: slime mold and discuss exactly how it finds its way out.
Speaker 1: All right, we're back. So the maze. We we did
Speaker 1: a whole episode on mazes, and we discussed what they
Speaker 1: are and what they symbolize for us humans. Essentially, you're
Speaker 1: talking about uh binding, confusing pathway corridors that end in
Speaker 1: dead ends while other corridors take you ever closer to freedom.
Speaker 1: So we often use these in science experiments. Put a
Speaker 1: mouse inside of a maze. See what happens when it
Speaker 1: gets stressed out? See if it can find its way out?
Speaker 1: What happens when you put a slime mold into a
Speaker 1: maze is really fascinating because now, for one thing, you
Speaker 1: do have to sort of um. You have to create
Speaker 1: a situation where the slime old quote unquote wants out,
Speaker 1: the slime mold wants to find its way to food.
Speaker 1: So that becomes the the idea here um for a
Speaker 1: dead end. To be a true dead end, it needs
Speaker 1: to not have something that the slime old can eat
Speaker 1: at the end of it, whereas they dad end with
Speaker 1: food at the end of it is essentially kind of
Speaker 1: an exit. So they found that if you put a
Speaker 1: Researchers have found it that if you put a slime
Speaker 1: mold inside of this maze, it will start off by
Speaker 1: mapping its environment out. It will send out these uh,
Speaker 1: these tendrils, and they will follow every course in the
Speaker 1: maze to its end. And if they find a true
Speaker 1: dead end where everything just ends and there's no food there,
Speaker 1: then it will retract, but it will leave a trail
Speaker 1: of slime that kind of works as an external memory
Speaker 1: of where it has been, and that is a that
Speaker 1: is a hallway that it need not go down again
Speaker 1: because there's no food down there, and then it will
Speaker 1: concentrate its efforts on the pathways that do lead to food. Yeah,
Speaker 1: it's really cool. As you say, it's like this externalized
Speaker 1: spatial memory and um. And again no brain. Creature does
Speaker 1: not have a brain, and it is not intelligent in
Speaker 1: the larger sense of the word. But it is is
Speaker 1: using a certain amount of matt making intelligence. It's using
Speaker 1: that chemical scent to figure out where it's been and
Speaker 1: then not expend the effort on searches that won't pay off. Right,
Speaker 1: So it's saying, I've been down that hallway, there's no
Speaker 1: no reason I need to redouble my efforts on this.
Speaker 1: Another cool thing is that the five serum slime mold
Speaker 1: sends these tendrils of protoplasum out search for food. And
Speaker 1: it's but but it's not just hey, wholesale everybody find food.
Speaker 1: What they do is they say, okay, this one over
Speaker 1: here to the left has found some food. These guys
Speaker 1: over here on the right have not. All right, everybody
Speaker 1: reconfigure and now let's bolsh for our efforts to that
Speaker 1: food to the left. So they reorganize themselves to then
Speaker 1: sort of go in and effectively cover that food spectrum
Speaker 1: that they did find, which is amazing. So not only
Speaker 1: are they making sure that they're not going into areas
Speaker 1: they've already been, but when they do find food, they're
Speaker 1: able to to sort of say, all right, troops, here
Speaker 1: we go, We're now going to some trade on this.
Speaker 1: All right. All of this is really amazing when you
Speaker 1: look at it in the context of engineering problems that
Speaker 1: we humans try to solve every single day. Yeah, particularly
Speaker 1: um it's it's interesting when you take the slime mold
Speaker 1: and you put it over a major city, and then
Speaker 1: you distribute the food in a way that resembles uh,
Speaker 1: major population points, major points of interest, places that you
Speaker 1: need to say, a public transportation system to reach. So
Speaker 1: if it were a map of Atlanta, for instance, you
Speaker 1: would have like central Atlanta, Midtown, you'd have the Bucket
Speaker 1: area where we are, and and various other important places.
Speaker 1: Um well, several of those in both places are probably
Speaker 1: not gonna reach by public transportation down here as far
Speaker 1: as the train goes. But that's a whole another story.
Speaker 1: But you put the slime mold in there and you
Speaker 1: let it figure out the best ways to get to
Speaker 1: its food sources, and researchers have found that the paths
Speaker 1: that the slime mold creates are comparable to the major
Speaker 1: public transportation system in those cities. You know, we've seen
Speaker 1: this again and again. It's not just Okay, there's just
Speaker 1: one set of researchers doing this. But I think the
Speaker 1: standout in this is the Tokyo railway system. Um, it's
Speaker 1: a two excuse me. In two thousand and ten, mathematical
Speaker 1: biologists toshi Yuki naga Aki and his colleagues observed how
Speaker 1: this networking behavior could translate into efficient city planning. So
Speaker 1: they drew a map of Japan. They put oat flakes
Speaker 1: on the map to represent cities, and then they let
Speaker 1: the five serum loose on the area that represented Tokyo, Okay.
Speaker 1: So key to this is that they're obviously going to
Speaker 1: be obstacles in city planning, like waterways that you can't
Speaker 1: you have to make sure that you didn't try to
Speaker 1: transverse long standing buildings and areas that you're just not
Speaker 1: going to bulldoze to build your right. So what they
Speaker 1: did is they took bright lights in these areas and
Speaker 1: which slim olds will avoid they do not like, and
Speaker 1: so those represented those areas that they knew that you
Speaker 1: couldn't do any sort of public transportation around. And then
Speaker 1: what bloomed in front of the researcher with the FI
Speaker 1: serum network that produced interconnections just that were strikingly similar
Speaker 1: to the layout of the Tokyo railway system and um
Speaker 1: in the ways that they differed from the actual Tokyo
Speaker 1: railway system. It turns out that their methods of reaching
Speaker 1: uh net networked UM places was much more effective that
Speaker 1: than what was already in place. So what we're saying
Speaker 1: here is that slime molds are solving engineering problems. I mean,
Speaker 1: this is amazing. This is stuff that we spend a
Speaker 1: lot of time on. This is these are computer programs,
Speaker 1: are modeling that's going on, and you just let a
Speaker 1: sly old loose and they can help. It'll equal or
Speaker 1: exceed human production on those of those same trade routes
Speaker 1: are same public transportation routes. Because another one that I
Speaker 1: ran across what was they were actually able to get
Speaker 1: up of the serum to um to reproduce the silk
Speaker 1: road in various other global trading routes. Put it on
Speaker 1: a map of the Earth and you'll see, oh, it's well,
Speaker 1: there's a silk road right there. It's thinking along the
Speaker 1: same lines as uh as as as humans did when
Speaker 1: they were trying figure out how to get from a
Speaker 1: point A to point B in the most effective manner possible, right,
Speaker 1: And when they took that globe to they configured it
Speaker 1: so that again there were certain places that that mold
Speaker 1: couldn't try to transfer because of the configuration of the
Speaker 1: continents and the continents of that time. And so they
Speaker 1: tried to reproduce that and that is amazing that the
Speaker 1: silk road came up. That popped up. Another example I
Speaker 1: think it's really cool is this is by Andrew Adamatzki,
Speaker 1: and he's a researcher at the University of West England.
Speaker 1: He wanted to figure out what would happen in the
Speaker 1: nuclear disaster. In other words, if a reactor melted down,
Speaker 1: what would be the best course of action for citizens
Speaker 1: to flee from it. So he took those ice eilier
Speaker 1: modes that um that are used for highway like patterns,
Speaker 1: and they grew a slime mold network of highways for Canada.
Speaker 1: And then they placed a crystal of salt which repels
Speaker 1: slime molds on the map where the Bruce nuclear power
Speaker 1: plants located in Canada. And then what they found is
Speaker 1: that the slime mold abandoned its tendrils near the salt
Speaker 1: and then grew a new highway pattern that efficiently re
Speaker 1: routed food across Canada and also showed different paths that
Speaker 1: you could leave obviously this area. So it sheds some
Speaker 1: sort of light on what can happen in disaster situations. Yeah,
Speaker 1: that's it's just amazing to think about slime mold is
Speaker 1: that is, being capable of doing this um and again
Speaker 1: it ultimately makes us rethink what intelligence is, um is
Speaker 1: as we we look at possible models for extraterrestrial life. Yeah.
Speaker 1: Adam Rogers, he's a senior editor at Wired. He has
Speaker 1: a really interesting riff on this, so if you want
Speaker 1: to see his video, check that out on Wired dot com.
Speaker 1: I believe the column is observation Deck Intelligent slime Molds
Speaker 1: and the applications here with slime molds, I mean, aside
Speaker 1: from possible shooting scenarios that were in addition to UH
Speaker 1: their biophysicist in Germany and Singapore who think that the
Speaker 1: mathematical models that they were agam based on sly mold
Speaker 1: behavior might lead to new ways to starve tumors of
Speaker 1: blood and essentially to a fight cancer, Yeah, which is
Speaker 1: because what they found is that again there's this mathematical
Speaker 1: similarity in the ways that a tumor tries to gain
Speaker 1: nutrients from the body and the way that slim mold grows.
Speaker 1: So taking those those two um examples, they can actually
Speaker 1: try to figure out ways that they could try to
Speaker 1: starve that tumor. As you say, yeah, I mean it
Speaker 1: all comes down I think to the idea you think about, Okay,
Speaker 1: what is what is mathematics? What is our what is
Speaker 1: our spatial understanding? What is what is the the ability
Speaker 1: to create a map on a piece of paper as
Speaker 1: a as an intelligent human like, it all comes down
Speaker 1: to our ability to navigate the physical world. Um, it's
Speaker 1: just kind of a an ability that has grown, uh
Speaker 1: for more robust with the passage of time, with our
Speaker 1: evolution and then with our the building of our culture.
Speaker 1: But at it's at the very like base level, something
Speaker 1: even without a brain, has to be able to do
Speaker 1: this to some level. And the and the slime mold
Speaker 1: does a fantastic job. So if you ever find yourself
Speaker 1: lost wandering about, think about, yeah, I think about the
Speaker 1: serum polysphal um, and take take heart in saying that
Speaker 1: this uh, this organism that goes back a billion years
Speaker 1: can find a way and so too can you. All Right, well,
Speaker 1: there's slime Mold for you, and that finishes out our
Speaker 1: three episodes on slime. If you missed it any of
Speaker 1: the other two, do check them out. There's a lot
Speaker 1: of cool data in there, and it really really made
Speaker 1: me rethink what slime is. And really, as I mentioned before,
Speaker 1: a long time fan of slime loved slimy monsters, slimy
Speaker 1: things even as I hated slugs, and uh, and there's
Speaker 1: just so much more there, uh, not only understanding how
Speaker 1: slime works, but but slugs as well. I mean, they're
Speaker 1: I think, to slug like monsters that have appeared in
Speaker 1: various uh forms of fiction and even once where they
Speaker 1: do a pretty good job of making the creature monstrous, like,
Speaker 1: they really don't dive into all of the just weird
Speaker 1: and fascinating biology of a slug. So just putting that
Speaker 1: out there, are there any potential filmmakers and fiction weavers
Speaker 1: in the audience, Well, let's call the robot over and
Speaker 1: do one quick listener mail this when it comes to
Speaker 1: us from Catherine and she has a book recommendation for us,
Speaker 1: She says, Robert and Julie, your most recent podcast made
Speaker 1: me think of one of my favorite books by my
Speaker 1: favorite author. For a great book about pretending to be
Speaker 1: someone you're not, I recommend Mother Night by Kurt Vonnegut.
Speaker 1: The main character is an American playwright who has spent
Speaker 1: most of his life in Germany. As an adult, during
Speaker 1: World War Two, he was recruited by the US government
Speaker 1: to help transmit messages to the Allies. He does this
Speaker 1: via code inserted into his Nazi propaganda radio show. He
Speaker 1: is so good at pretending to be a Nazi that
Speaker 1: he has respected as a leader within the Nazi Party.
Speaker 1: He also managed to get on the list of wanted
Speaker 1: war criminals. The problem is that he entered this knowing
Speaker 1: that the U s would never recognize his work, nor
Speaker 1: would they come to his defense. So really, the only
Speaker 1: people invested in keeping him alive or the nazis a
Speaker 1: group he does not truly want to be a part of.
Speaker 1: There's a movie made of the book starring Nicknolty. Read
Speaker 1: the book. Thanks as always for the entertainment and education.
Speaker 1: I hate the term entertainment. Yeah, I don't think we
Speaker 1: really use entertainment either. But let's got a bit of
Speaker 1: a musty ring to it. Yeah, but we hit the idea.
Speaker 1: But we're we're glad that we're providing some interesting tidbits
Speaker 1: for you guys. That's an awesome book recommendation, something I
Speaker 1: definitely want to follow up on. Yeah, I've I've only
Speaker 1: read a couple of Vonnegut stories of read Slaughterhouse Five
Speaker 1: and The Sirens of Titan. Good stuff, especially Slaughterhouse Five,
Speaker 1: one of my all time favorites. So hey, if you
Speaker 1: want to reach out to us, you want to share
Speaker 1: some stuff with us, you want to see what we're
Speaker 1: up to, what we're blogging about, what links we're looking at,
Speaker 1: maybe get an idea of what future episodes will consist of.
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