The search for alien life (on Earth)

The following is a conversation with Michael Levin, his second time on the podcast. He is one of the most fascinating and brilliant biologists and scientists I've ever had the pleasure of speaking with. He and his labs at Tufts University study and build biological systems that help us understand the nature of intelligence, agency, memory, consciousness, and life in all of its forms here on Earth and beyond. This is the Lex Fridman Podcast. To support it, please check out our sponsors in the description, where you can also find links to contact me, ask questions, give feedback, and so on. And now, dear friends, here's Michael Levin.

You write that the central question at the heart of your work, from biological systems to computational ones, is how do embodied minds arise in the physical world, and what determines the capabilities and properties of those minds? Can you unpack that question for us and maybe begin to answer it? Well, the fundamental tension is in both the first-person, the second-person, and third-person descriptions of mind. So in third-person, we want to understand how do we recognize them, and how do we know looking out into the world what degree of agency there is, and how best to relate to the different systems that we find. And are our intuitions any good when we look at something and it looks really stupid and mechanical, versus it really looks like there's something cognitive going on there? How do we get good at recognizing them? Then there's the second-person, which is the control, and that's both for engineering but also for regenerative medicine, when you want to tell the system to do something. What kind of tools are you going to use?

You said this about physics before. Can you just linger on that and expand on it, what you mean, why physics is not enough to understand life, to understand mind, to understand intelligence? You make a lot of controversial statements with your work. That's one of them because there's a lot of physicists that believe they can understand life, the emergence of life, the origin of life, the origin of intelligence using the tools of physics. Yeah.

Okay. So if there's no line, is it still useful to talk about things like the origin of life? That's one of the big open mysteries before us as a human civilization, as scientifically minded curious homo sapiens. How did this whole thing start? Are you saying there is no start? Is there a point where you could say that invention right there was the start of it all on Earth? My suggestion is that it's much better than trying to define any kind of a line, okay? Because inevitably I've never found, and people try to... You know, we play this game all the time when I make my continuum claim. Then people try to come up, "Okay, well, what about this, you know, what about this?" And I haven't found one yet that really shoots that down, that you can't zoom in and say, "Yeah, okay, but right before then this happened, and if we really look close, like here's a bunch of steps in between," right? Pretty much everything ends up being a continuum, but here's what I think is much more interesting than trying to make that line.

Can you actually explain briefly what a xenobot is and what an anthropod is? So one of the things that we've been doing is trying to create novel beings that have never been here before. The reason is that typically when you have a biological system, an animal or a plant, and you say, "Hey, why does it have certain forms of behavior, certain forms of anatomy, certain forms of physiology? Why does it have those?" The answer is always the same. Well, there's a history of evolutionary selection, and there's a long, long history going back of adaptation, and there are certain environments, and this is what survived, and so that's why it has. So what I wanted to do was break out of that mold, and to basically force us as a community to dig deeper into where these things come from.

Another pothead question. Is it possible to look at, speaking of unconventional organisms and going to Richard Dawkins for example with memes, is it possible to think of things like ideas? Like how weird can we get? Can we look at ideas as organisms then creating barriers for those ideas, and seeing are the ideas themselves... If you take the actual individual ideas and trying to empathize and visualize what kind of space they might be operating in, can they be seen as organisms that have a mind? Yeah. Okay, if you want to get really weird, we can get really weird here. Think about the caterpillar-butterfly transition, okay? So, you've got a caterpillar, soft-bodied kind of creature, has a particular controller that's suitable for running a soft body, you know, kind of robot. It has a brain for that task, and then it has to become this butterfly, hard-bodied creature, flies around. Okay. During the process of metamorphosis, its brain is basically ripped up and rebuilt from scratch, right? Now, what's been found is that if you train the caterpillar, so you give it a new memory, meaning that if the caterpillar sees this color disc, then it crawls over and eats some leaves. Turns out, the butterfly retains that memory.

So this is a good place to talk about the increasingly radical weird ideas that you've been writing about. You've mentioned it a few times, the Platonic space. So there's this "Ingressing Minds" paper where you described the Platonic space. You mentioned there's an asynchronous conference... ... Happening, which is a fascinating concept because it's asynchronous. People are just contributing asynchronously. So what happened was this crazy notion, which I'll describe momentarily, I have given a couple talks on it. I then found a couple papers in the machine learning community called the Platonic Representation Hypothesis, and I said, "That's pretty cool. These guys are climbing up to the same point where I'm getting at it from biology and philosophy and whatever. They're getting there from computer science and machine learning." We'll take a couple hours, I'll give a talk, they'll give a talk, we'll talk about it. I thought there were going to be three talks at this thing.

You've got to tell me more about this behavior that is observable, that is unrelated to the explicitly stated goal of a particular algorithm. So you looked at a simple algorithm of sorting. Can you explain what was done? Sure. First, just the goal of this study: there are two things that people generally assume. One is that we have a pretty good intuition about what kind of systems are going to have competencies. So from observing biologicals, we're not terribly surprised when biology does interesting things. Everybody always says, "Well, it's biology, you know, of course it does all this cool stuff." And yeah, but do we have these machines? And the whole point of having machines and algorithms and so on is they do exactly what you tell them to do, right? And people feel pretty strongly that that's a binary distinction, and that's what we can carve up the world in that way. So I wanted to do two things.

What was the thing you mentioned with the anthrobots that they can reverse aging? There's a procedure called an epigenetic clock where what you can do is look at particular epigenetic states of cells and compare to a curve that was built from humans of known age. You can guess what the age is, okay? So we can take now... And this is Steve Horvath's work, and many other people, that when you take a set of cells you can guess what their biological age is, okay? So we make the anthrobots from cells that we get from human tracheal epithelium. We collaborated with Steve's group, the Clock Foundation. We sent them a bunch of cells and we saw that if you check the anthrobots themselves, they are roughly 20% younger than the cells they come from.

Going back to the Platonic space, I have to ask if our brains are indeed thin client interfaces to that space, what does that mean for our mind? Can we upload the mind? Can we copy it? Can we ship it over to other planets? What does that mean for exactly where the mind is stored? Yeah. Couple of things. So we are now beyond anything that I can say with any certainty. This is total conjecture, okay? Because we don't know yet. The whole point of this is we actually don't really understand very well the relationship between the interface and the thing.

Let me ask you more explicitly on the SETI, the Search for Unconventional Terrestrial Intelligence, what do you hope to do there? How do you actually try to find unconventional intelligence all around us? First of all, do you think on Earth there is all kinds of incredible intelligence we haven't yet discovered? I mean, guaranteed we've already seen in our own bodies, and I don't just mean that we are host to a bunch of microbiomes or any of that. I mean your cells, and we have all kinds of footwork on this, every day they traverse these alien spaces, 20,000-dimensional spaces and other spaces. They solve problems. I think they suffer when they fail to meet their goals, they have stress reduction when they meet their goals. These things are inside of us, they are all around us. I think that we have an incredible degree of mind blindness to all of the very alien kinds of minds around us, and I think that, you know, looking for aliens off the Earth is awesome and whatever.

What advice would you give to scientists, PhD students, grad students, young scientists that are trying to explore the space of ideas given the very unconventional, non-standard, unique set of ideas you've explored in your life and career? Let's see. Well, the first and most important thing I've learned is not to take too much advice, and so I don't like to give too much advice. But I do have one technique that I've found very useful, and this isn't for everybody, but there's a specific demographic. There's a lot of unconventional people reach out to me, and I try to respond and help them and so on. This is a technique that I think is useful for some people. How do I describe it? You need to... It's the act of bifurcating your mind, and you need to have two different regions. One region is the practical region of impact. In other words, how do I get my idea out into the world so that other people recognize it? What should I say?

I agree with you. I think it's incredibly beautiful. I lied, there's an even more ridiculous question. So it seems like we are progressing towards possibly creating a superintelligent system, an AGI, an ASI. If I had one, gave it to you, put you in the room, what would be the first question you ask it? Maybe the first set of questions? There are so many topics that you've worked on and are interested in. What is there like a first question that you really just, if you can get a solid answer, what would it be? I mean, the first thing I would ask is how much should I even be talking to you? For sure. Because it's not clear to me at all that getting somebody to tell you an answer in the long run is optimal. It's the difference between when you're a kid learning math and having an older sibling that'll just—