Lex Fridman Podcast
#325 – Michael Levin: Biology, Life, Aliens, Evolution, Embryogenesis & Xenobots
01 Oct 2022
Michael Levin is a biologist at Tufts University working on novel ways to understand and control complex pattern formation in biological systems. Please support this podcast by checking out our sponsors: - Henson Shaving: https://hensonshaving.com/lex and use code LEX to get 100 free blades with your razor - Eight Sleep: https://www.eightsleep.com/lex to get special savings - LMNT: https://drinkLMNT.com/lex to get free sample pack - InsideTracker: https://insidetracker.com/lex to get 20% off EPISODE LINKS: Michael's Twitter: https://twitter.com/drmichaellevin Michael's Website: https://drmichaellevin.org Michael's Papers: Biological Robots: https://arxiv.org/abs/2207.00880 Synthetic Organisms: https://tandfonline.com/doi/full/10.1080/19420889.2021.2005863 Limb Regeneration: https://science.org/doi/10.1126/sciadv.abj2164 PODCAST INFO: Podcast website: https://lexfridman.com/podcast Apple Podcasts: https://apple.co/2lwqZIr Spotify: https://spoti.fi/2nEwCF8 RSS: https://lexfridman.com/feed/podcast/ YouTube Full Episodes: https://youtube.com/lexfridman YouTube Clips: https://youtube.com/lexclips SUPPORT & CONNECT: - Check out the sponsors above, it's the best way to support this podcast - Support on Patreon: https://www.patreon.com/lexfridman - Twitter: https://twitter.com/lexfridman - Instagram: https://www.instagram.com/lexfridman - LinkedIn: https://www.linkedin.com/in/lexfridman - Facebook: https://www.facebook.com/lexfridman - Medium: https://medium.com/@lexfridman OUTLINE: Here's the timestamps for the episode. On some podcast players you should be able to click the timestamp to jump to that time. (00:00) - Introduction (06:40) - Embryogenesis (14:08) - Xenobots: biological robots (27:55) - Sense of self (37:27) - Multi-scale competency architecture (48:58) - Free will (58:27) - Bioelectricity (1:11:44) - Planaria (1:23:33) - Building xenobots (1:47:08) - Unconventional cognition (2:11:39) - Origin of evolution (2:18:42) - Synthetic organisms (2:25:27) - Regenerative medicine (2:29:14) - Cancer suppression (2:33:15) - Viruses (2:38:28) - Cognitive light cones (2:43:03) - Advice for young people (2:47:47) - Death (2:57:17) - Meaning of life
Chapter 1: What is discussed at the start of this section?
The following is a conversation with Michael Levin, one of the most fascinating and brilliant biologists I've ever talked to. He and his lab at Tufts University works on novel ways to understand and control complex pattern formation in biological systems. Andre Karpathy, a world-class AI researcher, is the person who first introduced me to Michael Levin's work.
I bring this up because these two people make me realize that biology has a lot to teach us about AI, and AI might have a lot to teach us about biology. And now, a quick two-second mention of each sponsor. Check them out in the description. It's the best way to support this podcast. We got Henson Shaving for a great razor and shave. Eight Sleep for e-commerce. Element for on-the-go electrolytes.
And Insight Tracker for biological tracking. Choose wisely, my friends. And now, on to the full ad reads. Never adds in the middle. Those suck. I try to make these ads here interesting. So they're worth listening to perhaps, mostly because a lot of them don't have anything to do with a sponsor. They're almost like inspired by the sponsor. But if you still must skip, please check out the sponsors.
They're the reason I'm able to do this podcast. So please support them in any way you can. I enjoy their stuff. Maybe you will too. This show is brought to you by Henson Shaving, a family-owned aerospace manufacturer bringing precision engineering to your shaving experience. You had me at engineering.
If there's any word a person can state to me that, you know, I was going to say turns me on a little bit, but that would be very inappropriate to do an ad read, so I would never say a thing like that. But anyway, I find engineering just... in all of its forms. Materials engineering, mechanical engineering, civil engineering, all of it. I love it.
They're using aerospace grade CNC machines and because of that are able to make metal razors that extend just 0.0013 inches, which is less than the thickness of a human hair. And And the precision of it is the reason you can have a safe, clean, smooth shave. Check them out at hensonshaving.com to pick your razor and use code LEX and you'll get 100 free blades with your razor.
You must add both the 100 blade pack and the razor for the discount to apply. This episode is also brought to you by Eight Sleep and its new Pond3 mattress. It is a source of happiness for me. Naps bring joy to my heart. They put to rest all the anxiety, the uncertainty, the sadness, the melancholy that I have on my heart. They let that fade and the phoenix rises from the ashes of the nap.
And a cool surface of the bed with a warm blanket. I just love it. It's usually going to be about 20 to 30 minute nap. Cures all ills. I can have so much uncertainty, so much fear, so much anxiety about the world. And just a little nap. Or insecurity. All of it. A nap can cure it. And maybe that's a gift. Maybe that's a chemical gift for me.
I'm so fortunate not to suffer from sort of chemical depression that can hold you down for many days, weeks, or months. For me, a nap can cure so much. And it's beautiful. I mean, sleep is so, so important. So I highly recommend Eight Sleep. It's been, like I said, a source of a lot of happiness for me. Check it out and get special savings when you go to eightsleep.com slash life.
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Chapter 2: How does embryogenesis transform physics into cognition?
Meaning that, oh, I see, in order to take this action, here's the information that got processed via this
chemical mechanism or whatever immediately people say oh well then that's not real cognition that's just physics and i think this is this is fundamentally flawed because if you zoom into anything what are you going to see of course you're just going to see physics what else could be underneath right that's not going to be fairy dust it's going to be physics and chemistry but that doesn't take away from the magic of the fact that there are certain ways to arrange that physics and chemistry and in particular the bioelectricity which which i like a lot uh
to give you an emergent collective with goals and preferences and memories and anticipations that do not belong to any of the subunits.
So I think what we're getting into here, and we can talk about how this happens during embryogenesis and so on, what we're getting into is the origin of a self, with a capital S. So we are selves, there are many other kinds of selves, and we can tell some really interesting stories about where selves come from and how they become unified.
Yeah, is this the first, or at least humans tend to think that this is the level at which the self, with a capital S, is first born. And we really don't want to see human civilization or Earth itself as one living organism. Yeah. That's very uncomfortable to us. It is, yeah. But, yeah, where's the self born?
We have to grow up past that. So what I like to do is I'll tell you two quick stories about that. I like to roll backwards. So as opposed to so if you start and you say, OK, here's a paramecium and you see it, you know, it's a single cell organism. You see it doing various things and people will say, OK, I'm sure there's some chemical story to be told about how it's doing it.
So that's not true cognition. Right. And people will argue about that. I like to work it backwards. I say, let's, let's, let's agree that you and I, as, as we sit here are examples of true cognition, if anything is, if there's anything that's true cognition, we are, we are examples of it. Now let's just roll back slowly, right?
So you roll back to the time where you're a small child and used to doing whatever, and then just sort of day by day, you roll, you roll back and eventually you become more or less that paramecium. And then, and then you sort of even below that, right. As a, as a, as an unfertilized OSI. So, um,
It's no one has, to my knowledge, no one has come up with any convincing discrete step at which my cognitive powers disappear, right? It just doesn't, the biology doesn't offer any specific step. It's incredibly smooth and slow and continuous. And so I think this idea that it just sort of magically shows up at one point and then, you know, humans have true selves that don't exist elsewhere.
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Chapter 3: How do planaria demonstrate regenerative abilities?
You guys don't be the head. And so it'll amplify symmetry breaking amplification. You get one embryo. There's some neural tissue and some other stuff forms. Now, now you say, OK, I had one egg and one embryo and there you go. What else could it be? Well, the reality is and I used to I did all of this as a grad student.
If you if you take a little needle and you make a scratch in that blastoderm in that in that disc such that the cells can't talk to each other for a while, it heals up. But for a while, they can't talk to each other. What will happen is that both regions. will decide that they can be the embryo and there will be two of them.
And then when they heal up, they become conjoint twins and you can make two, you can make three, you can make lots. So the question of how many selves are in there cannot be answered until it's actually played all the way through. It isn't necessarily that there's just one. There can be many.
So what you have is you have this medium, this undifferentiated – I'm sure there's a psychological version of this somewhere that I don't know the proper terminology – but you have this ocean of potentiality. You have these thousands of cells and some number of individuals are going to be formed out of it, usually one, sometimes zero, sometimes several.
And they form out of these cells because a region of these cells organizes into a collective that will have goals, goals that individual cells don't have. For example, make a limb, make an eye. How many eyes? Well, exactly two. So individual cells don't know what an eye is. They don't know how many eyes you're supposed to have, but the collective does.
The collective has goals and memories and anticipations that the individual cells don't. And the establishment of that boundary with its own ability to pursue certain goals, that's the origin of selfhood.
But is that goal... in there somewhere? Were they always destined? Are they discovering that goal? Where the hell did evolution discover this? When you went from the prokaryotes to eukaryotic cells, and then they started making groups, and when you make a certain group, you make it sound And it's such a tricky thing to try to understand.
You make it sound like the cells didn't get together and came up with a goal. But the very act of them getting together revealed the goal that was always there. There was always that potential for that goal.
So the first thing to say is that there are way more questions here than than certainties. OK, so everything I'm telling you is cutting edge developing stuff. So it's not as if any of us know the answer to this. But but here's here's here's my opinion on this. I think what evolution I don't think that evolution produces solutions to specific problems.
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Chapter 4: What are xenobots and how are they created?
He rediscovered gap junctions. But when I visited him in Woods Hole maybe 20 years ago now, he told me that he was writing, and unfortunately he passed away, and I think this book never got written. He was writing a book on gap junctions and consciousness. And I think I think it would have been an incredible book because because gap junctions are magic. I'll explain why in a minute.
What happens is that just imagine the thing about both these ion channels and these gap junctions is that many of them are themselves voltage sensitive. So that's a voltage sensitive current conductance. That's a transistor.
And as soon as you've invented one, immediately you now get access to, from this platonic space of mathematical truths, you get access to all of the cool things that transistors do. So now when you have a network of cells, not only do they talk to each other, but they can send messages to each other and the differences of voltage can propagate.
Now to neuroscientists, this is old hat because you see this in the brain, right? There's action potentials that, you know, the electricity, You can you can they have they have these awesome movies where you can take a zebra like a transparent animal like a zebrafish.
You can literally look down and you can see all the all the firings as the fish is like making decisions about what to eat and things like this. Right. It's amazing. Well, your whole body is doing that all the time, just much slower. So there are very few things that neurons do that other cells, that all the cells in your body don't do.
They all do very similar things, just on a much slower timescale. And whereas your brain is thinking about how to solve problems in three-dimensional space, the cells in an embryo are thinking about how to solve problems in anatomical space. They're trying to have memories like, hey, how many fingers are we supposed to have? Well, how many do we have now? What do we do to get from here to there?
That's the kind of problems they're thinking about. And the reason that gap junctions are magic is, imagine, right, from the... from the earliest time. Here are two cells. This cell, how can they communicate? Well, the simple version is this cell could send a chemical signal. It floats over and it hits a receptor on this cell, right?
Because it comes from outside, this cell can very easily tell that that came from outside. Whatever information is coming, that's not my information. That information is coming from the outside. So, I can trust it, I can ignore it, I can do various things with it, whatever, but I know it comes from the outside. Now imagine instead that you have two cells with a gap junction between them.
Something happens. Let's say this cell gets poked. There's a calcium spike. The calcium spike or whatever small molecule signal propagates through the gap junction to this cell. There's no ownership metadata on that signal. This cell does not know now that it came from outside because it looks exactly like its own memories would have looked like of whatever had happened, right?
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Chapter 5: What are xenobots and how do they relate to robotics?
non-essential kind of surface uh limitations of of technology and imagination that were true before but they've got to go and so and so we call them xenobots so so xeno for xenopus lavis it's the frog that these guys are made of but we think it's an example of of of a biobot technology because
Ultimately, once we understand how to communicate and manipulate the inputs to these cells, we will be able to get them to build whatever we want them to build. And that's robotics, right? It's the rational construction of machines that have useful purposes. I absolutely think that this is a robotics platform, whereas some biologists don't.
But it's built in a way that all the different components are doing their own computation. So in a way that we've been talking about. So you're trying to do top-down control on that biological system.
And in the future, all of this will merge together because, of course, at some point, we're going to throw in synthetic biology circuits, right? New transcriptional circuits to get them to do new things.
Chapter 6: How do cells communicate and coordinate during embryogenesis?
Of course, we'll throw some of that in. But we specifically stayed away from all of that because in the first few papers, and there's some more coming down the pike that are, I think, going to be pretty dynamite. that we want to show what the native cells are made of. Because what happens is, you know, if you engineer the heck out of them, right?
If we were to put in new, you know, new transcription factors and some new metabolic machinery and whatever, people will say, well, okay, you engineered this and you made it do whatever and fine. I wanted to show and the whole team wanted to show the plasticity and the intelligence in the biology. What does it do that's surprising before you even start manipulating the hardware in that way?
Yeah, don't try to over-control the thing. Let it flourish. The full beauty of the biological system.
Chapter 7: What is the significance of the Xenopus laevis frog in biological research?
Why Xenopus laevis? How do you pronounce it?
The frog. Xenopus laevis, yeah.
Yeah, it's a very popular- Why this frog?
It's been used since I think the 50s. It's just very convenient because- You know, we keep the adults in this very fine frog habitat. They lay eggs. They lay tens of thousands of eggs at a time.
Chapter 8: How can understanding biology lead to advancements in regenerative medicine?
The eggs develop right in front of your eyes. It's the most magical thing you can see because normally, you know, if you were to deal with mice or rabbits or whatever, you don't see the early stages because everything's inside the mother. Everything's in a petri dish at room temperature.
So you have an egg, it's fertilized, and you can just watch it divide and divide and divide and all the organs form. You can just see it. And at that point, the community has developed lots of different tools for understanding what's going on and also for manipulating it, right? So people use it for understanding birth defects and neurobiology and cancer immunology also.
So you get the whole embryogenesis in the Petri dish.
Yep.
That's so cool to watch.
Is there videos of this?
Oh, yeah. Yeah, yeah. There's amazing videos online. I mean, mammalian embryos are super cool too. For example, monozygotic twins are what happens when you cut a mammalian embryo in half. You don't get two half bodies. You get two perfectly normal bodies because it's a regeneration event, right? Development is just the kind of regeneration, really.
And why this particular frog? It's just because they were doing in the 50s and
It breeds well in, you know, it's easy to raise in the laboratory. And it's very prolific. And all the tools, basically for decades, people have been developing tools. There's other pieces. Some people use other frogs. But I have to say, this is important. Xenobots... are fundamentally not anything about frogs.
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