Ep #28 Transcript | Lee Cronin: Life's Origins, Alien Biochemistry, Discovering Life Beyond Earth
Full episode transcript (beware of typos!) below:
Professor Lee Cronin, thank you for joining me.
Lee Cronin 3:47
It's great to be here. Can you do a brief intro for people in terms of who you are and what you do at a very high level.
I'm an academic at the University of Glasgow in a School of Chemistry, although I'm trained as a chemist, but really I would say that I am an theoretician that can only do theory by doing experiment, which seems a bit weird. And my medium of choice, through happenstance happens to be chemistry and stuff like in touch. And I'm interested in control of matter from the top down, and like human beings and how life got going. So from the bottom up, and how information gets processed in the universe.
Nick Jikomes 4:34
Interesting. So you do a lot of theoretical work, you do a lot of chemistry work. I want to get into some of that. But a lot of it does center on this very broad, very deep question of what is life? And I thought maybe we could start by having you maybe paint a brief picture for people of the intellectual history of this question, who are some of the major thinkers and ideas that have grabbed Hold with this question that have perhaps influenced your own thinking.
Lee Cronin 5:04
Okay, yeah, that's a huge question. And it goes back to antiquity, right? When people were trying to figure out what the, you know, the ancient Greeks were thinking, the Bible, of course. So I won't go to the Bible, the ancient Greeks, because I'm just not a very good scholar of ancient history. But I would say that in terms of who have influenced me, I think that I'm incredibly, I've been influenced by I suppose Charles Darwin, if you read his book, it is really interesting the way he kind of this this state this thing that's evolution just become self evident. After a while, I think some physicists have influenced me in terms of shining, Einstein strutting around but bit more curious because he thought that he understood what an unsolved problem life is. And then I suppose coming on to today, and Freeman Dyson, I found really inspiring, a very interesting lady at the Weissman is still alive and kicking it on us, who she got the crystal structure of the rhizome. And she has influenced my thinking a lot. Sarah Walker, ASU, Arizona State University has influenced my thinking on that life is more than just stuff, there's something else but it's not magical. It has to do with information or what we might call information. Yeah, there's lots of I suppose Newton actually, for just being basically a very odd person, clearly very lonely intellectually, and just playing around with reality and himself. And I think that, you know, Newton kind of isn't that was an alchemist who happened to do some physics. But he was a pretty nasty person by if you look in the history book, so he didn't, he has influenced me, not because of his nastiness, but just because he is the way he framed it, you know? And so, yeah, but in really, right now, there's a lot of interesting people interested in this problem, but they are all I would say, not seeing the elephant in the room if maybe we don't either or the or the life in the universe.
Nick Jikomes 7:18
And so I want to maybe start to talk about what maybe let's talk about first what all life forms have in common on Earth. So what are the core features of life as we know it on Earth? And how does that maybe tie into how you start to think about how life arose?
Lee Cronin 7:36
Yeah, so let's start from a very basic materialistic point of view, all life on Earth. As we look at it, it has carbon in it. So if you were, so that's one thing, there are common elements. So I think you could say, you know, my periodic table, mark here, so. So, you know, having carbon, nitrogen, oxygen, sulfur, and phosphorus, and some chlorine is important. But I think that if you were looking at life, on earth, from it, as from a naturalist point of view, and you had a microscope, and you had a video camera, you would be able to say a number of things about life is that some things move around. And, and some things don't. But if you look at the things on the microscope, you can see a cellular structure. And if you're fast enough to capture the things that moved around, you will also find they have a cellular structure. And if you looked at seawater, or even river water or anything, and you looked in the microscope, you would see cells, so that you would I suppose just from looking through your eyes, you'd say, well, the stuff going on, there's these things that look like capsules, or packets or whatever, and they appear to be doing stuff. So I think that that is kind of the starting point, isn't it from a very phenomenological point of view that life appears to be these things. And if you wait some time, these things move, divide, and appear to look like they're warm, right? They give off heat. So and if you take away the fuel, or what we might call fuel, they no longer give off heat, and they no longer move, and they no longer replicate. So there's something odd going on with this matter, this thing is able to autonomously wander around and take resources from the environment that doesn't look like itself, and then manufacture more of itself. And if you think about it like that, that's kind of weird, isn't it?
Nick Jikomes 9:29
Yeah, just the basic idea that you've got matter. And it's got a particular shape, essentially. And somehow it's reproducing itself. It's causing more stuff to look like it. You've talked in some talks online about this notion of selfish matter, just sort of generalizing the the term, the famous phrase from biology that there's a selfish gene that genes are the sort of units of replication, perhaps the smallest units of replication, and I'm wondering if you could talk a little bit about it. Your idea of selfish mattered and whether or not genes are the smallest unit of replication, or what the smallest unit of replication might actually be in principle?
Lee Cronin 10:09
Yeah, I think selfish matter's a good one. And also, I mean, not just selfish. But in, you know, some matters lucky because it's animated, right? It gets to go places other matter doesn't go. And just to give you a segue, before I answer that question, I always, I wasn't really that fascinated by biology. Growing up, I was fascinated with physics and chemistry and mathematics and computers. But now and then when I stop and look, and I look at a wall, and there's made of a piece of grass or something growing up and you think, and you know, what's there, right, there's replicating machinery, there's ribosomes just growing there, you just, for me, it's like a source of wonder that I don't think I'm ever going to shake it is so incredibly interesting, that there are ways that that life is kind of characterized by these little capsules of matter, that a minimally, no, they're islands in their own right, they can go away and just TerraForm their surroundings. And so, so yeah, going to selfish matter. I suppose that all math, if you think about what evolution is doing, and I suppose that by calling it selfish, a man prefer more fighting, and I suppose actually, it's not selfish matter, there happens to be matter that's able in the current environmental conditions to be successful. And what and we don't even there that sound for more for more fighting. So what are you meaning is so selfish, successful, we can't do that, okay, let's say persistent or persistent, it's kind of, okay, just there and able to reproduce itself and say, what you do is you go from this selfish to this kind of functional object, and you can start to realize that through time, this matter is able to maintain its form, repair itself, and reproduce. And so there is some processing going on. And I think it's fascinating that that, then that, where that matter is, if you're almost acts like a singularity in space, where it's drawing fuel and stuff through that points, and something's happening in that point, there's some information that there's something going on, where it's able to take this dead stuff, and literally, you know, make make a living soul of it. So actually, I shouldn't say living. So we know, give it the essence of life, right. And we don't know what that we didn't know what that was hundreds of years ago, we now know what that is in terms of, you know, producing cells. And in those cells, there's DNA and RNA and stuff. So that's kind of my notion is that you have this inanimate stuff, which has maybe some chemical wealth to it, it's got the right bonds, that you need the right elements. And then I can procure that and extract resources. And those resources I can use to build more of myself. And to also kind of do something interesting, I've got, you know, I've got this resource, I'm going to consume this resource, I'm going to metabolize it, build with it. But then when I go through the process of replication, I'm going to allow there to be not a faithful, all I'm going to do is the best I can, and making a proper copy. But it's some errors come in, and I'm going to tolerate that because maybe those errors will act as a probabilistic program to make my my new offspring, better, fitter, more able to survive in the environment that may or may not be changing. And so you have this really interesting search algorithm, that animated matter with selection is able to basically record what's going on in environment over time. And that may be arguments be argumentative, it might be the all animate matter. You know, if you pick one of your atoms that's animate. So at what level does that atom become animated? Around inanimate well, is in the network of surrounding objects? So that's a rather complex answer to the question, but I think it would provides us a lot of points to get in and dig in and really explore what we mean by the living state. Because if I took one of, you know, one of your carbon atoms and ran away with it, that wouldn't, you wouldn't be that unhappy because you have a lot of carbon atoms. So we know that the life isn't just in the atom, it's in some other aspect. And I love to play games with chemists and biologists and physicists and say, Well, you know, if we all agree, that's the same atom. Where is where is the life?
Nick Jikomes 14:31
What, what is the importance? It seems like one of the most important features of these self replicating patterns that we call life is their encapsulation, that there is a cell there's a separation of an internal environment from the external environment. Could you speak a little bit about just some of the basic biology there for people who might not know about, you know, lipid bilayer 's and things and what do you think the importance is of having that bilayer Are that that cell that separates an internal from an external environment? And is that strictly necessary?
Lee Cronin 15:07
Yeah. So it kind of also amplifies what you're saying. And last question, I realized I didn't answer entirely like the mote the minimal unit of of life. And so you you suggested, is it a gene? And let me answer. So let me just carry on and then go on to the cell. So a gene is not a minimal unit of life actually is not the minimum thing that selected upon that people. It is a unit. But as you're alluding to, right now, objects, molecules are not alive. Genes are not alive. It may look like they're alive, I can as a biotechnologist, I could evolve that gene in the laboratory, is that the minimum unit? No, because the gene needs me to be enslaved to it, moving my syringes around doing stuff, and you're like, oh, gosh, so if the gene isn't selfish, what really is selfish? And I think that then we've got to do is zoom out and say, what is the minimal viable unit of biology on it? If and that's what you've just kind of said, well, you know what, let's talk about a cell. So a cell is, so what is it that say the minimum viable human bodies appears to be a cell? And what is a cell a cell is literally an object which has an ID, which has an inside, which is to some degree protected from the outside world? So what does that mean? Well, that mean, the contents of the inside has a fairly good memory cell was a bit like a book. But it's a bit more than a book because the book, a reader has to come and read it, but the cell can read it. So that a book, a cell is a book that can read itself. You see what I mean? So you have the contents of the book. And if the book could read itself, and then act on it, with the information in suddenness, well, the cell can do. And so and the reason why the cell needs a boundary, so it could be a lipid bilayer. And the lipid bilayer is simply a bit of soap, if you like, there's a head and there's a tail. And the water loving heads will basically gather together to make a kind of make one type of leaflet or they'll do the go the other way around, depending on when you've got reverse micelle or, or micelle. And, and the greasy part or just form this lovely layer. And so will act as a barrier between the inside and the outside. But not only does it act as a barrier, it allows some movement of staff from the outside world to the inside world. And the inside of the cell has an elaborate control mechanism, which has been involved to basically respond to the outside world, but not too quickly. So you can get stuff in now. So really, the cell is the most minimal viable unit of, of evolution. But it's not quite that because not everything can survive. And it's all a bit on its own because what it means to have an individual cell, Is it viable? Yes. But maybe you need to give it some amino acids, maybe it needs some oxygen, maybe it needs some co2, maybe some sugar, where does that come from? And then you start kind of getting this really weird mind bending, well, what is the minimal unit? And then, and then you come to the conclusion? Well, there is no minimal unit. But there are different types of object which are more autonomous than others. So a bacterial cell is very autonomous on Earth, it can go anywhere, find food, viruses are not so autonomous, they have to get in the cell to do their thing. And I think that the cell is characterized by a number of objects, so I'm actually answering your questions because I realized there was a tendency it's not. So there are some genetic material in the cell, which is, you know, explicitly written down and what something we will call a code. People claim as a digital code, I don't think it actually is. But okay, we can talk about what that means. There is a metabolism that goes on, which is able to basically provide
open up and close ion channels, there's literally a pump, I should view the cell a bit like a one, those bouncy castles that you have to have a pump keeping blowing up so the kids are happy. And basically, for the bouncy carpet castle to remain viable, you have a pump that blowing air into a continuously. So a cell is a bit like a bouncy castle, it remains inflated, but as long as the machinery is keeping it inflated, and that requires glucose or some kind of sugar. So you've got so you've got it needs to be in places there needs to be ions going in, there needs to be raw materials going in. And then the cells also responding to signals from the outside. And then as a response to signals from the outside, it may change its internal mechanism. So it may go defensive, or it may start to say, hey, there's plenty of food, I'm going to replicate now. So I'm going to make another copy of me because times are good, and why not? That's what you know, that's what's supposed to happen and they will make a copy of itself. It may be that it's a liver cell. So it was an organ in me it would be got a drug to detoxify. It will do his job as a liver as a liberal do which we detoxify that make it water soluble and do its thing. So I think that the cell really has a role in its in the function. And there's also a support system to keep that cell viable. So it can repair itself as well, or copy itself. So they're kind of all the different things that can happen. But the interesting thing is the lifecycle of the cell, the cell when it copies itself, that process in populations, where is where you read information from the environment, into the cells and cell very slowly learns about the environment over time. And that's kind of the mechanism of evolution that we can discuss.
Nick Jikomes 20:44
And how closely how closely tied to the notion of of what it is for something to be alive, is the concept of Darwinian evolution, I think it seems like most modern thinkers today would, would pretty much say that those two things can't be separated that if something is alive, it is capable of undergoing Darwinian evolution, do you? Do you view it that way? And
Unknown Speaker 21:07
yeah, I would, I would say that everything alive has come through a causal chain of evolution. Or everything that maybe is living so there's so my friend Sarah Walker, and Michael Lachman wrote a really nice piece called we should describe, which, which is a beautiful piece, but it's still confusing, because they talk about life, and the live, and I would rather talk about living and evolving. So, you know, I would say to you, alright, Nick, have you got kids? Do you have to intend to have kids? Are you having, you know, Keeper, you might say, well, I want to know if you're just simply living or if you are evolving. Yeah. Okay. So the so really, living things are capable of evolving, but not all, living things have to evolve, there are dead ends right in, you know, there are some people that choose not to have children, there are some species that are the product of a union of two, I always get the donkey and the mule mixed up. But But But basically, there are some things that are no longer fertile. And therefore, you know, you wouldn't say you have no animal rights for that object, you wouldn't abuse that object more because it was wasn't capable of evolution any longer, you would treat that with the same respect, because it's a sentient being of well, sentience. It's a conscious animal. Right. And I have to be very careful my terminology here. Yeah. So I think
Nick Jikomes 22:32
so I suppose to if you think about, like, the very beginning that we'll talk about the origins of life, there could have been many dead ends that sprung up before something sort of
Unknown Speaker 22:40
took. Oh, yeah, absolutely. And so I think that really, evolution doesn't care about what is living, it cares about and what is evolving. As I said, as I say to some people, when I'm playing those, like I said, Look, you know, life is difficult, you know, what you we evolve together, you die alone, right? So you know, what I mean by that is that evolution doesn't really care about your death, per se, other than your loss to the population. But what evolution does care about is how you contribute to the population in the environment, selecting going forward. So obviously, the act of death can be important, because you might release resources, you might do something else. So I think there is this chain, well, I'm really interested this causal chain going back to Luca, where you are acting in that and the information that you've gathered, you push into the future, but you could build artifacts in your life, these podcasts even right, that they will go on and influence other people. Right, that wouldn't in a certain way that they wouldn't, they may do things as a result of hearing your podcast that he would not have done otherwise, and affect the very future of humanity. And so in a way that we are now transcending, we are above that type of evolution, because we're in this technological world, we can communicate in lots of different ways. So evolution is very good for biology. But as far as technology is another layer on top of that, and can have influence global influence in a different way. So And technology is alive, it is living, and people don't. And this is where the integrated information people when the talking about consciousness, confused everybody else because everything conscious well, actually consciousness is also distributed phenomena we can talk about later if you want. So it's really important to understand that chain of reasoning and that chain of data. What really interesting to me at some point, we may be able to produce some informational artifacts that we get off Earth that we can send to Mars, and there may be a terraform Mars and put life on Mars. That's got nothing to do with the physical, biological causal chain of life on Earth. Even though if it wasn't for us, there would be no Martians, but that's going off a totally different times. Maybe for later.
Nick Jikomes 24:49
Yeah, I do think I want to circle back to this connection. I think that that maybe many people don't make but some have between questions like the origin of life. Questions like the origin of mind or consciousness? Because there is this replicative quality to mental activity that that is really interesting to think about, by analogy with things like genetic evolution. You mentioned a term that I want to unpack for people, though you mentioned Luca. And so I'm wondering if you could just describe for people, what is Luca? And why do we think there was one single origin of life? For life forms on Earth?
Unknown Speaker 25:27
Yeah, that's good. So let's, let's answer that precisely. And I'll tell you what I think so Luca stands for the last universal common ancestor. And it's a really beautiful notion, because if you look at all the cells on Earth, let's just say, all the cells we know of, we look at them, and we were able to look inside, we would see some really important things, we all seem to share the same type of building blocks in proteins in, in our functional parts in the cell, and our memory of the cell and the DNA and RNA, it seems to be quite similar. And obviously, there's different sophistication. So some cells have more complex proteins, and others. And what you can kind of do is put all these in the line, and kind of infer a kind of tree of life, not not just tax them on it Taksin, I can't even say taxonomy tonic, but I can say that you can, but also genetic, so you can go back. So now you can say, right, you can imagine going back back back, it's almost like in ancestry, things you can do now, right? In our mitochondrial DNA, we know that our mitochondrial DNA came from my mother's from their mothers and their mothers, and it's a really good way you can use to trace how human beings have moved around the world. So we go back, and there's less and less and less of us. And you can imagine back just at the origin of life, that there is this first cell that springs up that has all these bits and bobs ready, just is the seed that gives rise to all of biology. Now, that's a one out rather wonderful term. But I don't think there was one Luca, I think that I think that's rather, I don't think that's even neat required, because I think what we mean on earth is that there's lots of environments on Earth, which are kind of similar, and there's chemistry that's kind of similar. And there's lots of competition through phases, where Luca, like objects are coming. And it's almost like, you know, like Luca, or the LUCA idea is the first expression of global democracy. And that basically, once I, I've got this really important, you know, I've got this better RNA than you, but I can die occasionally. And so that doesn't work. Right. So as a catastrophic, therefore, I've got this better, I want to use 25 amino acids, but I can't encode it properly, because the error correction goes. And so there's kind of like there was all these pre Luca technologies fighting it out. And in the end, you it's a bit you all solve the problem in the same way. Like it's like saying there's a Luca was like saying there was only one point where human being invented fire. Clearly not. It was just the conditions were right. So I think Luca is more of expression in da logical time. And chemistry on Earth, where basically conditions were right, for the minimal viable cell to emerge. And it might have happened over 10s, if not hundreds of years, because you got to the point a little bit of wire where suddenly you had you know, I don't know if you remember video, you look young to me via Betamax and VHS fighting it out and which one would survive, and then arbitrary decision was made. And suddenly, everyone has adopted the paradigm. So I think that Luca is merely a term that should be given as an umbrella. And I wouldn't be surprised if we find some cells on Earth deep in the Earth's crust that are slightly splitters just before Luca and they were like, you know, no, this is our form of biological democracy, we're only going to have this signature. And because they were in a very special niche isolated from the rest of the earth, they could survive, it'd be really interesting for us to find those we are searching, but as of yet, we haven't really found many concrete examples, if any, kind of find some little bit. So. So I think lewco is really a state of biologic pre biological democracy. I just made that up. Sounds quite good. I'll take a note of that for later.
Nick Jikomes 29:12
So let me reiterate that to see if I'm following. So you're almost saying basically, the idea of Luca is essentially, if you just look under the hood, and you look at every cell, whether it's an animal, cell or a plant cell, there's differences, but they're all basically doing the same basic stuff. We're all using DNA with the same basis, we all have the same core cellular machinery, and therefore we must be descended from a thing that had those core components. One
Unknown Speaker 29:39
day I was gonna say also, though, it is, it is correct to say that using a process of bioinformatics and probability, you can trace for sure, in some species, the sequence space going back so you'll know for sure that this species of animal gave rise to this one because the combinatorial space of genetic code is just too large. I won't want to just add that in there. So to be entirely correct, got
Nick Jikomes 30:04
it. And then you're basically also saying that there was certainly at least the potential or the plausibility for a kind of convergent emergence of life. So just because we, we infer this thing called Luca, because the biochemistry is very similar across different life forms present today, that may have simply been that, you know, to use your fire analogy, people, and this happens a lot in evolution, right, similar constraints and different locations will allow the independent origin of traits. And so maybe, maybe life did originate multiple times, but it merely looks like it came from a single origin, because the same set of constraints were applied at different time points at different places of the earth.
Unknown Speaker 30:46
Yeah, exactly. And I think that not only that, what we might be able to see, if we were able to replay the tape all the way back, we might find that in our own cells, we have three or four different origin of life, since a common common date, so our mitochondria probably came from one origin of life, you know, our other organelles came from other origins of life and then just got mismatch together. It's a bit like, you know, when people are copying technologies, oh, that's a good idea, I'll steal that here. I'll horizontally transfer it here and here. And probably the VAR, the space of viruses that exists on earth, may help us replay that, but the information is so vast, we're going to do a lot of computing, a lot of bioinformatics, a lot of sequencing to even get a hint of that. But my guess is that we are not just the sum of one or two origins of life, but many 10s if not hundreds, or 1000s.
Nick Jikomes 31:42
And so I think related to that notion, is the question of how easy it is for life to evolve, is it? You know, you seem to be implying by saying that there could be many origins so that, in some sense, it's made, perhaps more likely than we once thought for life? To actually get started? How do you think about the question of how easy it is for inorganic matter to actually become living?
Unknown Speaker 32:09
So I think it's ridiculously easy. And we're just looking at it entirely wrongly. I think that the, the, so I think the process that we're looking for, I call it is selection. So there's a selection in the universe without before biology, biology speeds it up. And I think selection is as prevalent as gravity, right? Where there's massive gravity, where there's master selection, okay, now you need to think about that. In other terms, they will, okay, there's no selection going on on the moon, well, maybe there was, but the selection is a very productive. So selection needs some processing to go on. But I think that we have missed it. And we've been so obsessive about the complexity of life on Earth, we haven't understood the mechanism, which gives rise to the information storage, of happenstance from the environment. That is really what life is, life is the ability to store what happened in the past, play it again, and use that to your advantage to add up to basically animate yourself, if I was to put rather crudely. So I think that the process of selection, everyone says it's vastly hard, one of my big Gamble's in my academic career, and I love taking them my Gamble is the selection, the process that gives rise to the origin of life is as common as the process of that gives rise to planets and black holes and stars. So it must be staring us in the face, they must find it in the lab.
Nick Jikomes 33:41
So would you say that, in your view, life is inevitability that it's sort of just a natural extension of the same process of evolution going all the way back to the Big Bang, that it's just simply going to crystallize out of matter. If you let the universe cool down for long enough, basically, yeah,
Lee Cronin 34:01
that life is merely I would say, making fun of the physicists today. The physicists today think that physics is this very small field or very big field, but very fundamental, you know, forces, behavior phenomena and lifelike name. Um, you know, I can break the laws of physics or I make new laws of physics that are consistent with the old ones. So as of I would say, life is like the blockchain of physics. The blockchain is like the is all out there. You can go back to the beginning and understand it and look at all the processes of proof putting stuff in there. And what life does is it forks, that chain of possibilities and just plays with matter? And I think that that's something that's hiding in plain sight, and we just haven't been able to see it. So there will be a revolution I predict in my lifetime. I'm trying to start it. I think I'm onto something along with a few other colleagues. It's probably about 20 of them in the world. You see this way. And that we see that selection is a very, very simple thing that happens everywhere. Selection naturally gives rise to evolution and evolution to be efficient and just make cells on Earth, the most efficient way to make life is to make cells. Now, it might be on other planets where there's higher pressures and densities, there are other ways to do selection. And life looks a little bit different. Who, you know, one of the things that worries me is that we're so off on the causal chain. We're so forked, if you like from the main, you know, I Okay, you know, let's use the Bitcoin analogy that blockchain of matter or physics, that we wouldn't actually recognize other forks. So what we've got to try and do is think more open mindedly about what the processes are, and then go, oh, maybe that's an alien. We just haven't recognized it before. Because we're so we departed from that mode of matter understanding such a long time ago. But I to ask you a question. I think I'm there hints in my own lab, that selection is easy to see. But we're really at the limits of, of analytical chemistry right now. Because the way of scales and doing it. And also, I'm finding a huge amount of bias, not because and this is not bad bias. This is not bad. Well, there is I mean, there's bad bias ever. What I mean is that, as a scientist, you're taught by your teachers, and you're taught by the literature. So you can call that information, or you can call it bias. Okay? Now, when that basis bias is useful, it's information, right? When that bias is kind of not necessarily proven, it's more a narrative, then it stops you from doing more work. And there is a huge narrative and chemistry about origin of life, which has stopped the field from doing anything for more than 50 years. That's why I do not work in origin of life. I work in artificial life. The origin of life is a very good discipline, but it is rife with narrative, and ego. Like all science, we all have egos. I mean, I have an ego too. But I but my curiosity is a little bit bigger than my ego, just a little bit. And but that's not maybe the case for all areas of science.
Nick Jikomes 37:12
You hinted at something that I think we'll return to, which is, you know, in order to remove certain biases, in terms of how you would identify signatures of alien life, say, one would want a technique that is completely agnostic about the mechanics of that life, you want to sort of just see, see some afterglow or after a fact of life, no matter what it actually looks like, before we get to that stuff. I wanted you to riff a little bit more on what are some of the major hypotheses that people take seriously today about the kinds of environments on Earth, either now or in the past where life might most plausibly have arisen? So things like deep sea vents and things like this, are there? Is there sort of a shortlist of candidate terrestrial environments for where we think life may have arisen?
Unknown Speaker 38:02
Sure, there's a shortlist as long as the kind of the individual cults, if you like, in the field, right. But that but let's try and be as agnostic as possible. So Darwin's warm pond seems quite good. Under the ocean, a deep sea event seems quite good people are fascinated by these, these volcanic growths under where you've got these black smokers, these chimneys, where you've got rocks and porous materials, and high temperature and all sorts of stuff happening. You could imagine life occurring in aerosols in the air. I mean, it's harder to believe, but you know, it could even occur in ice, there are some people seeing that you can have interesting chemistry going on in ice. So you have these environmental constraints. So in the sea, on on on the earth, in a cave, lot. There's lots of these conjectures, but people say, Oh, no, no, there was no possible near because there was no, there was, you know, it had to happen in the sea, because all the earth was there, you know, covered in this in this in water, or whatever. And then you have all these other things going on. So it's very difficult, you know, you can pick your hypothesis. But what then happens away from these environments, then breaks into various chemical hypotheses were yours people say the RNA world, which is the hypothesis that the chemistry produced the building blocks of RNA, and these could self assemble in some way. And because RNA can act as a functional molecule can do stuff, as well as store information, you got two purposes for the for the price of one and RNA was the, you know, did something special. Some people think that lipids came first, and that somehow you had lip, you had this lipid world. Some people think that proteins came first. And so and some people think that chiral molecules came first so chiral molecules and molecules or have had they're left handed or right handed and a chiral molecule is we've got two identical molecules and you can't superimpose them. They're inanimate so it's a bit so there There's a whole bunch of them. And and actually, it's quite funny because people like to argue about which one is the most pre biotic li plausible? And, and I find that very amusing, because of the prebiotic be plausible is like, well, it's like a lawyer, right? You know, trying to go to the supreme court and say, what is the demand precedent here? What do you think? And then it keeps changing. So there's lots of I would say there's three or four environmental hypotheses. Okay, on ice grains as well, by the way, in crystals in rocks, there's three or four chemical hypotheses, and then there's a mixture of all of those together.
Nick Jikomes 40:37
So there's really a lot of scenario that sounds like and, you know, it could be any one or all of the above. What about a slightly different question, which is, if you sort of give us maybe a very abridged chemistry, one on one education, if we're thinking about the periodic table, how much constraint is there on the kinds of chemistry that could even conceivably result in life? So obviously, we've got carbon based life here on Earth. People often speculate about silicon based life because silicon is similar to carbon in certain ways. I imagine there's actually a relatively small space of elemental possibilities in terms of which atoms could actually serve as that kind of backbone of life. How should we think about this? And how it relates to the question of how alien alien life would actually be and how it might have similar similar chemistry.
Unknown Speaker 41:32
You I think if we can go all the way back you need so I mean, as long as you can prescribe describe a configuration in matter, you might have the possibility for evolution, I'm not saying you're going to get life neutral living neutron stars, that doesn't seem very plausible, can't store enough bits. So I guess what I'm pulling back a bit, because I just don't know, I'm a really poor chemist, I only know about the chemistry of life on Earth, why where's my bias come from? My bias is coming from one atmosphere, one bar, one atmosphere 25 degrees C, okay, you know, tonight, Kelvin, and then the composition of material I find around me on earth. And so all I would merely say at the moment is that chemists the life biology on Earth, is merely a reflection of the chemistry that was available at the origin of life, and also could provide us with the right evolutionary dynamic. So and this about available matter. Now, you look up in our sources, you say, well, Mars, Mars looks like, you know, a red planet is maybe lots of iron, lots of inorganic stuff doesn't look very alive, ergo, iron is not very good for life. We just don't know enough about the environmental conditions and how life, how fragile life is in that regard about radically changing environments, it could be that life is a phenomena that is coupled to an planetary environment. And as long as the environment is stable, for a long enough period of time, you get to you get to homeostasis on a planetary scale. And then as soon as a planet flips out for some reason, so Mars lost its atmosphere, because the sun just drifted away having a magnetosphere, but there's no plate tectonics and anything like that, that basically life just naturally died. And so but that's kind of one take, if you look at the periodic table, go your planet of choice, the element, if you've got elements that are abundant, or capable of covalent bonds, and you've got reasonable temperature and reasonable pressure, then carbon is good, because it just is able to form molecules that can store information easily. But I can imagine all sorts of other things under pressure. I mean, gosh, what, what could a chemist do under 200, atmospheres and a lot of temperature, they can make all sorts of phosphorus, oxygen, phosphorus, boron, you know, what we call main group compounds, you can make, you can make interesting compounds with metals and hydrogen, it we just don't know. And Titan, that people are gonna we're going to go to Titan in a few years. That's interesting, because it's cold. There's lots of liquid alkanes in there. And gosh, what could happen in liquid alchemy, you might use a different type of very weak bonding, not strong carbon carbon bonds, that bonds that we would call Supra molecular interactions. So you might just have these kind of very weak bonds that could maybe our evolutionary dynamic to occur. So it really, I would say two things about the limitation on life. You need elements. And you need configurations, and unit where there's bonding, there's hope. So what I mean when I say life, when there are bonds, there's hope. I don't care how strong the bonds are. If the bonds are really weak, but the planets really cold. Knock yourself out, you can still have life. If the planet's really hot, but the bombs are really strong. Knock yourself out. You can still have life. We should stop obsessing about our Goldilocks zone, because our Goldilocks zone He's a anthropomorphize just by us.
Nick Jikomes 45:03
So it sounds like you would actually say that, you know, traditionally, when we think about the search for life elsewhere, people are looking for exoplanets earth like planets that have the environment that's like ours. But it sounds like you're saying that we should even be much more open minded that that that in a completely different environment, Chemically speaking, you could have chemistries that give rise to life, potentially, that we would think of is terrible for giving rise to life in the context on Earth. But different temperatures, different pressures could allow for the use of other atoms to just do things that are almost unthinkable if we're, if we're not. If we're not thinking outside the box or outside the planet, literally,
Unknown Speaker 45:43
outside PV equals nRT. We just got it. We just got to step out of that. I think it's fascinating. I mean, if you think about it, the fascinating thing is, you look at there are only four types of exoplanet. There are dead ones. That is there ones that maybe will always be dead. But let's know that it's not let's, let's not say all exoplanets. They say all exoplanets have the right to life one day, but there's just no there's dead ones. There's living ones, there's ones that are technological, and they're ones that are much living, but now dead, you think about only four types of exoplanets out there. So when you look at these exoplanets, they will fit into one of those four categories. So we should start thinking about them being in those four categories and try and statistically map them. With that in mind, let's stop worrying about whether we exist a lot. Let's pretend that out of all the exoplanets we see then that one of those categories. And then, you know, it doesn't mean that there are other categories, I suppose you could have like pre life, but you know what I mean, broadly speaking, dead, alive, technological, always dead or dead so far. I think that's a good set.
Nick Jikomes 46:47
In terms of the origin of life on Earth, the the story that you typically hear in like middle school or high school biology in the US, is the Yuri Milner experiment, where essentially, you just take a soup of stuff, you zap it with electricity, or whatever, and you look to see, do you get living things swirling around in there more or less? Can you describe that for people who don't know it and, and maybe start to talk about today, experiments that you're doing or other people are doing, where, you know, are people doing modern day Yuri Miller experiments to try and create?
Unknown Speaker 47:22
We are in my lab, I keep trying to forgive the pun, kill the experiment, but it keeps living. I'll tell you why in a minute. So familiar is a really simple experiment, say, Hey, we're going to take a reaction. So it takes some gas and some water. So we'll take let me see if I can remember, ammonia. So that's NH three in the source of nitrogen, hydrogen, h2, h2o, and methane, CH four. Okay. And we'll put them all together, we'll have a couple of tungsten electrodes. And that tungsten electrode is actually which I think is quite interesting. I will add 50 KKV to those electrodes, and this spark will go across will be refluxing. refluxing means to boil the all this stuff boiling up and condensing around past electrodes. And there's a cycle so it's a natural kind of stuff boils goes up, as it falls down, it falls through electrodes get zapped on its way down. And you make basically you just given enough energy to make any Oh, crap, if you forgive the, I don't know if you want swearing on the podcast, but there's not too much more than that. So you make this stuff. And after some time, the solution changes color. Milan, your Mila. Mila Yuri did this. And, and after a few days, they were surprised when they will, maybe a few weeks actually, they took it out. And they analyzed and they found evidence amino acids. But, you know, in a way I was like, it's kind of like, yeah, of course, you think about it. Anyway, glycine, Glycine has nitrogen, oxygen, carbon and hydrogen in it, you've just taken the sorts of things and you blast them together. It's very simple molecule is easy to imagine. And yes, they made everything else as well. Really simple. It's like a combinatorial kind of card game, you know. So, but at the time, it was a seminal experiment. It got lots of people excited. But what it didn't do is it didn't produce any complexity in just cracked open the gases and made some organic molecules combinatorially. So just a bit like literally, if you if you're one of these people, I used to make no cars or yachts, or matchsticks or you've got your matchsticks and put them together and they clump into likes twos and threes, maybe four or five note, there's no car. No, you're nothing just boring matchsticks come together. So then people worked on it a bit more sophisticated to try and get more stuff to happen. And they didn't really see much more. There was even a paper where everyone was so desperate to see well they reanalyze the old samples 50 years on with modern technology and what they found way for you sitting down they found more amino acids. I mean, I was like no shit Sherlock Of course you could find More amino acids. I mean, it's a convent or explosion, do you not understand? And but, you know, it's a question of lack of ideas. So what was missing in the military was selection. It was just a glass bowl. Right? So what I've been trying to do in my, in my lab is to say, Hey, guys, let's now put some inorganic Earth's crust in it. Well, the first one we did actually, is Milan URI. And URI actually got the Nobel Prize, but he got the Nobel Prize for the discovery of deuterium, which is an isotope of hydrogen. And, and so I thought, were hilarious. Just make fun of the community to do the Miller Urey experiment, but do do tolerate it. See what happens on Planet deuteron. And Mike Groover, like, really, I was like, Come on, let's just buy some details. Oh, that's heavy water, and do it. But when we did it, we got different results. What we showed is when the water was heavier, you basically move around in a different way different speeds, and you get different compounds, which was mind blowing obvious to me afterwards, but before I was like, oh, okay, yeah, you change the way the stuff you have different isotopes, yet different compounds. So that was quite humble and quiet. Great. So we did that. And what we're doing now is we're trying to put different amounts of the Earth's crust in and say, if we have Earth's crust, and we can vary it, can we start to go from the soup that's on sculpted, just a mess. And can the minerals, select the crystal select some of the soup, and trap that somehow, and select it over time, and we're seeing evidence of that? I think we've seen the first evidence of environmental selection in a miller Urey type experiment. We're moving away from it because we're doing more sophisticated ones. But that's kind of where we are there. Other people do milah URIs as well, similar lines, but but maybe they have a different angle where they may be changing some of the chemistry or some of the pressure or something like that.
Nick Jikomes 51:57
So I know that this isn't a precise question. But is it your intuition that, you know, in terms of the ability to create life, literally, someone in a lab somewhere creating life in a beaker? Is that something that you view as relatively plausible, in the sense that it could very well happen within say, our lifetimes? Or how do you sort of think about the probability there you go into the lab every morning, wondering Is today the day where I walk in and there's something swimming around in there?
Unknown Speaker 52:29
Um, I want to but it's a big sociological problem with a PhD students trying to get them to do these experiments, because it's kind of I think it's, I thought it was gonna be easy to make a simple life form in the lab. And hasn't that been happening that easy? Not because it's that hard. But because doing long term experiments difficult to set up, we have to set up all the technology, we're building almost like a large hadron collider for origin of life right now. And so now, if you say that oh, no, your life or must have a ribosomes? How long would that take? I'll say, well, probably as long as it took the life on Earth, you know, maybe a few 100,000 few million years, because the ribosomes complicated, is only so much time, you know, the information, you can almost calculate how much time it would take on a causal chain, which I'm doing right now, actually, which is one of the reasons why I was inspired by adda your mouth. And I think thanks for her discovery, and we can count the subunits. And I think I know how long it takes to or how many selection steps you have to go through to make a ribosomes in the inorganic world, which is mind blowing. Because then you can work out how much mass how much time wishes like, gosh, but let's go back to your other point, if you make so if so, the quick answer is yes, I expect to make life in my lifetime pretty quickly. But I don't think anyone will believe me, because it's gonna be too simple. And everyone's gonna be arguing about is that life or not? So what I'm trying to do is break the problem down. And what I should do is try and break everyone's expectation down and say, Well, look, let's not call it Life, let's call it evidence of selection, and increase the sophistication and start to see a place where we can get selection. And then if the system starts to create a crude genetic system, where you can store information and read it out functionally, from nothing, then I think that I will start to convince people that this is the route to biology. But you can see how that's less satisfying than, you know, putting a load of stuff in a bell jar. Frankenstein moment, turn it on and come back the next day, and some blob good yo, hi, Cronin. I'm akoni Nice, you know, whatever.
Nick Jikomes 54:46
So thinking about what you mentioned briefly, something that on the one hand is pretty intuitive, I think but but I know that there's there's more to it that you've been working on this notion of chemical complexity, right. So I think on the one hand You know, anyone can understand that if a molecule is smaller and has fewer kinds of atoms and another molecule, it's obviously simpler. You can layer on the idea of the the 3d configuration that the molecule has. But can you talk a little bit about the notion of chemical complexity and how that's relating to some of your ideas about how we detect signatures of life, irrespective of the chemistry that that life actually has?
Unknown Speaker 55:23
Yeah, yeah. So in trying to going back to the definition of life, I think everyone was getting there. They're kind of literally getting themselves overly confused by arguing about what is life, everyone would have a new definition, right. And everyone would have a smarter definition, their definition of life. And it really, I really found the whole thing very amusing, and a little bit infuriating. And I said, Well, let's not argue about what because people say, you know, is a flame alive is a virus alive, is a politician alive, either less intelligent, or conscious, pick your take a bit. And then you and you get your round circle. We're arguing about what life may or may not be. And I was thinking, Well, look, what is it the life tends to do and require that makes it different to background processes in physics and chemistry? And then you get you're looking at sophistication and molecules and and how big and complex they are. And the problem with the word complexity is the mathematical physicists and computer scientists have been making complexity calculators for many, many 10s of years. And they're kind of not really, they're really cool abstractly, but they don't really tell us anything about reality. Because their complexity calculators are complex and not computable. So I found it really infuriating. Because I went to mathematicians, I was a chemist willing to cross over into a new field and say, Hey, I realize there's a problem in origin of life, we're not counting complexity properly, can you help and there were no boring, or we don't care, your, your way of doing it. Just use this method, use my method. So I went away. And I thought, right, I'm a chemist, I know about chemistry. What is it is interesting. And what I noticed is that if you do random military type experiments, you get a whole explosion of stuff. Easy, because there's just the atoms are bonded into each other. And I say, Okay, what, how far do I have to go before the molecules become so big? But complex? Not big like that, but not big and just a tar or a mess? But like, and I will say that molecule is not randomly produced? Is it even a worthwhile as a thought experiment? And I played with this for a good couple of years? And everyone said, no, no, of course, you can get complex random molecules. It just happens by chance. I said, Okay. But what about a Tesla or back then it's probably a jumbo jet. What about a jumbo jet? Is a jumbo jet, just a random? No, no, no, of course not. a jumbo jet was made by Boeing as jumbo jet. So Okay. All right, then what about protein? Well, of course, not a protein is a very complicated molecule made by evolution. So okay. So you do agree that there are some molecules that can form that are are, and then people start saying, Well, now, even protoid, even some proteins could be formed by chance, we just wouldn't know it's a protein. And we were calling protein noids. And so I kept pushing and pushing and pushing. And I realized that there was this blind spot in mathematics and computing science and chemistry in combinatorics. That because I know enough computer science, chemistry, mathematics and probability theory, I was able to work out that there are indeed, molecules that are so complex that can't form on Earth without the help of life. So I flipped it around another way and said, Okay, this rhizome is not strictly a molecule Rosen is really complicated thing, you would say, a molecular ribose. And people would tell you off this co2 molecule, which one is most complicated once a year, right, was that great? So okay, let's go down a bit. This molecule of glucose, is it more complicated than co2? Sure. But could it rise on its own? Probably glucose probably could. So then I said, Okay, where's the sliding rule between your co2 and your Reiber zone? And I think then you just pick your point where, okay, if I found this molecule, so I kept pushing and pushing and pushing. And that's where I started to kind of realize that there was a new theory of complexity. In fact, the first ever Theory of Complexity in any discipline that is actually computable and measurable. And I was like, because also people say, Oh, no, we can measure complexity. But they can't really, because it's not it has to go through an observer is not objective, they have to make some assumptions. So it's quite technical for here. But but we've been playing with that. And we realized we came up with a measure of molecular complexity. Now why is that account? Well, my hypothesis for life is don't worry about what defining life life as the process
Unknown Speaker 59:51
can create complex artifacts in abundance with multiple copies that no other process can do. That's my working thesis. So it's a bit like, you know, a bit like, I don't know, Rembrandt or, or, you know, Van Gogh, you know, the Van Gogh's Van Gough, whatever you'd say, basically, he would you know, the style. So when you found 10 paintings from that artist, you know, it's that artists because you recognize a configuration. So that's kind of a quite an elaborate answer to your question. But it's super important because it starts to remove the bias, because you don't need to know anything about the chemistry, we could dig deeper into that in a moment.
Nick Jikomes 1:00:31
So I do want to try and explain this on a very basic level. And this is related to what you're calling assembly theory, this idea that you can quantify quite precisely whether or not life is present based on the bouquet of molecules that you find, you know, somewhere in some environment, and in particular, the distribution of complexities that you measure, you know, in that soup of molecules. And when you say complexity and how you quantify it, it has something to do with the number of steps that it would take to construct any given molecule from the elemental, you know, Lego building blocks that that you have at your disposal. Is that accurate? How would you think about it?
Unknown Speaker 1:01:17
So what we tried to do is to define assembly theory, what assembly theory says you take a given object, you say, say take two objects, A and B, if you want it to basically work out which one was more complex, you were the one that took takes more steps to make it and the object is made out of bonds, you could basically break up or there's the making, take the molecule and break all the bonds. And then you say, right, I'm allowed to form all these bonds, again, what is the minimum number of steps from being super lazy to do it? Now, you go for what it will just be equal to the number of bonds in the molecule. But come on, let's take a shortcut, when you've made one type of bond or one motif once, you've already got that in your memory. Okay, so suddenly, so I've made this, I made this bond once, and if I need it, again, I can put it on my bucket. So if I put two bonds or three bonds together, and I got the that exact shape again, I can do it. But without incurring a penalty other than one step, not the three steps. So that allows you to compress the information into a causal chain of events. It's a bit like, if you imagine taking making a Lego, either no Millennium Falcon, or whatever Star Wars thing, I like Star Wars at the moment, my son does, your there are certain boring bits, we just have to add the bricks together and some intricate bit bits. But when you add the bricks together, that could be in this part or another part, whatever. So you've got that part already at your disposal. So it's a bit like those breaking down. So assembly theory is a probabilistic theory to say I took a hammer to my Lego bricks it all apart, it would, it would tell me the worst case scenario, or sorry, the best case scenario, the minimum number of steps I would need to take to get to that object probabilistically. And that seemed really nice, because then allowed us to then assess a molecule based upon the number of steps to get there.
Nick Jikomes 1:03:06
So literally, if we were to put this in terms of Legos for people, literally all this is, is if you look, if you had a tub of Legos, literally Legos, you've got blue ones, you've got red ones, all of the little individual Lego blocks. And you saw a pirate ship built out of Legos, you could say, Okay, there's 1000 different ways to put these blocks together to make that pirate ship. But it takes at least x number of steps, 500 Steps site to put things together to make the pirate ship. But for a simple, you know, rectangle, it only takes three therefore the pirate ships more complex.
Unknown Speaker 1:03:38
Exactly. So if you were able to see so the pirate ship, I would say, is a clear evidence of life and the sail. But hang on, there's only one pirate ship. So let's say we look at Mars and you see a pirate ship. And you and you think okay, it could be a one off. But now the beautiful thing about life and living systems, it doesn't just make one pirate ship. There's zillions of identical pirate ships. So when you say, ah, that's one pirate ship, and I can break it down. That's not life, you say, but hang on. Look at my 10 billion pirate ships are identical. And you're like, Whoa. So there has to be the so there has to be a process that's producing this pirate ship. And each of these steps is that information has to be encoded somewhere. Because why form the pirate ship? Why not form a racing car, Lego Santa or whatever? I must say that when I explained this to chemists and chemists still said, No, you're the pirate ship is somehow magic. And it's really interesting how in a discipline, when I was trying to play, get people socialized to this, they just would not accept the probability theory. They said there's something special but I'm like, Okay, if I write a book, at what point do you determine the book is written by me and not just a random type keys on typewriter so there's different like, Well, okay, but, you know, it is very interesting to kind of calibrate people into probability space. It's okay if you're a mathematician. Are you a statistical statistician, but a chemist somehow believing magical pirate ships?
Nick Jikomes 1:05:07
So, when you are calculating these numbers, I want to I want to paint a short picture of how you guys do this for people who are not chemists, and then talk about, like, how you would actually apply this to search for and find alien life on another planet. So you guys use mass spectrometry? And you've got a way to calculate this number for any given molecule. Can you just briefly explain for a non chemist? What is mass spec? And basically, how does this machine work?
Unknown Speaker 1:05:34
Yes. So if you want, I can take a step back and say, how'd you do for molecules, how my spec works, and I think of them fits more naturally. So the pirate ship, we're talking about the Lego bricks coming together encounter, you're talking about bonds holding the atoms together. So when when you have a bond in the molecule, that bond basically is a is a specific interaction that when you look at some colors, and you look at heat, you know, when you look at infrared, that's evidence of these bonds moving. Now, if you were to take a photograph of some molecules using infrared radiation, you've got lots of different colors coming out. And roughly speaking, each color corresponds to every different bond. So a different bond has a different energy, that means it vibrates at a different place. So the vibrations of the molecule give you the colors. So when if you have lots of colors associated with one molecule, you know, it's more complicated, count the number of Moloch count the number of color colors, you get exactly the complete the assembly number. Now there's got a mass spec was mass spec to well, in the particular version of mass spec, they use mass spec as a way of wearing a molecules, you put them all on the gas phase, and you basically have a big electromagnetic field and the mount Michael route moves around a curve. And you basically can calculate how massive it is. But there's more to it, what you can then do is you can then hit the molecule with some energy, and the molecule falls apart. And so the number of parts it falls into, give it number of fragments. So if you take a molecule, it's really simple. Excuse me, it could break into two equal parts. And you only see one part in your aspects that you mentioned the difference. So the more part different parts you see, the more complex it is. Now, in our mass spec experiment, you don't image one molecule, it's not possible, you have to image many millions at once you basically select them all, so they get partitioned. So you get through your one pirate ship versus a million pirate ships instantly. In the mass spec experiment, what you do is you can always see a minimum of 1000 pirate ships, 1000 molecules. So you basically do the mass spec, you see the molecular weights, you see the peak the molecule, so it's heavy, so it's like a heavy molecule, then you hit that heavy molecule. And you know that you only selected that one molecule, it's a special surgical instrument. And then you count the fragments. And the number of fragments is roughly equal to the assembly number. So that sounds really complicated. But simply mass spec sample in cm molecule hit the molecule doesn't molecule have more than 15 fragments, it's more than 15 fragments looks like it could be from life. So that's really the kind of detector that with the living detector system that we built.
Nick Jikomes 1:08:15
So it is really conceptually it's as simple as if you took your LEGO pirate ship. And then you just took a small block of just red Legos that were just red Legos in a rectangle, and you throw them against the wall, the pirate ship would break into pieces, and it'd be more different types of pieces that you'd see. Because it's more complex. It's got more components.
Lee Cronin 1:08:36
Yeah, exactly that, and then you just detect that. So that's, that's literally it. I mean, you could also you the nice thing about assembly theory is you can use it to see if people are cheating. So if you got someone who's playing cards, and you're able to count number of cards, you could actually see when these motifs come together, or when people are writing text you can see because the pattern in the text has a minimum number of steps to make the you know the word you can use it to see if it's got a common origin. Because the more copies, the more conspicuous it is. So I'm actually using assembly theory to look for plagiarism because what does life do very well plagiarizes itself makes copies of itself. And that's all it does. It tells you about those free variables in the information in there. But yeah, your analogy, we're breaking up a Lego is perfect and spot on is exactly how it works.
Nick Jikomes 1:09:27
And so it sounds like, it's obviously much more complicated than it's gonna sound. But you could take a machine like this, put it on a Mars rover, put it on a spaceship, send it somewhere. And you could do this type of experiment. And using assembly theory, you could detect whether or not life was present indirectly, without having to make any assumptions on what exactly that life looks like. You would simply be looking for the right distribution of highly complex molecules that you see over and over again.
Unknown Speaker 1:09:58
Yeah, I mean, I mean, there aspects on Mars right now sadly, they don't have quite the resolution, and quite the ability to hit a single molecule. But but we're sending an aspect of Titan soon on dragonfly that should be. And I think it's very easy to imagine an experiment that NASA have already sent rovers and ships with aspects, it's very easy to do it again and modify them and look for life agnostically. And what I'm saying is that if we are able to find a suitable The nice thing about the experiment, sorry, it's the way that the mass, but you can view it like a nose. So the mass spec basically draws molecules in to the lungs, if you like springs them in through the nose, and the lungs are where the detection occurs. And, and you really just have to get sample in the air in the air from space into the into the mass spec and just work out what you've got. And so what you can do is you can then look at the complexity by sniffing, sniffing the number of fragments, and just then follow the increasing complexity to to go and look for more and more interesting, you know, the source of molecules, and Nasser are going to do this now I think they it took me a while to convince them of this, because at the beginning, when I developed the technique, they said it was like, impossible. And then it was ludicrous. And now it's obvious. So I think they're the three stages of you know, a new idea, impossible, ludicrous, ludicrous and obvious, if you see what I mean. And so that's really exciting, because I think we will know for sure. Because we have the scale. We will be saying the machine to Mars to Venus, to Enceladus to tighten to IO, wherever we want to go. And we will be able to take molecules. And if their complexity is high, the higher the complexity of the assembly number. And notice I use the word assembly and not complexity, because it's within comparing them within classes. But it's just like, what molecule was the most assembled? How much information did it need to get there? And the more information, the more unlikely it is, that came from a biotic source. And yeah, if you're a real skeptic, you can say I need an assembly number of 1000. If you're really, you know, by going by what we have on Earth, and assembly number 15, if he didn't want to be in the Middle East, I'd say 30. And so what we're doing right now is checking that doing the measurements in the lab. But the nice thing about it is you do not need to know anything about the chemistry on the planet. You don't need to know anything about the history. It's all self consistent. There's no assumptions, no labels, your only assumption is that there are molecules present. And like that life can make complex molecules. And one of the
Nick Jikomes 1:12:49
one of the things I wanted to ask and I'll still ask it, even though it sounds like you've, you've sort of switched my my thinking on this, I was going to ask how many earth like planets are out there? Because I know that over the years, they've become more and more common, we've discovered more and more. But it sounds like you're saying we don't need we shouldn't be biased to thinking about life must be in a planet that's like Earth, we can actually potentially find it in a very different type of planet nonetheless, can you give people a sense for how many reasonably earth like planets are out there? And how common we think this is today? Oh, wow,
Unknown Speaker 1:13:25
I mean, that off the top of my head. I mean, the numbers are changing all the time. But actually, I'm gonna I don't think your question is a bad one. Because I'll come to why that isn't. Let me ask you a question. So if we can say that most stars that are similar to our sun have solar systems associated with them, and it would be that we see and they're say, I don't know, there's a few billion stars in, or at least a few 100 million, if not a few billion stars in the Milky Way, then and let's just say that say I know that say 25% of them are like our Sun. So let's say a few 100 million, and then a few and then at least 50% of those have solar systems and when there's so it's those solar systems, let's just say another 10% of those can have a few talking about at least 10 million Earths in the Milky Way, if not more. Now, why is that? Interesting? Why you know you're pulling back? Well, I like the idea of looking for us because what I meant what I think you mean by earth, water, carbon, Goldilocks zone quite because life on Earth with carbon and this gravity to this trajectory. It might be easier to talk to aliens from Earth like planet than aliens from another planet because our metabolism, the timescale on which we're interacting are going to be similar. It might be that life on some other planets may take them you know, a few 1000 years even to go through a metabolic you know, second for them. It just is I know it might that might seem insane, but who sets the time constant? Well, the time constant must be set by the reaction rate Right, and what what we know how we're able to move stuff around our pressure and temperature. So I would say looking for earth like planets is a good idea if we want to find intelligent life that we can communicate with. But I'm just I've just made that up just now in response to your self criticism, because I think it is a valid question. But I mean, I just made up numbers for Earth. But I think I've heard estimates in the Milky Way alone, that there are potentially hundreds of 1000s, if not millions of candidate, but that that's making some pretty, you know, wide assumptions. And they're going to get narrower, the aerobars. And those will get narrower with observation.
Nick Jikomes 1:15:40
Yeah. But for someone like me, who doesn't really know much about astronomy, and these things, you know, we're not talking about a handful, we're talking about a much, much higher order of magnitude.
Unknown Speaker 1:15:49
Yeah. I mean, there's and there's also lots of things about solar system dynamics, right? It wants it all also systems that really important because we've got these heavy planners in the outer atmosphere, our solar system that cleaned up everything, so earth wasn't bombarded and all this stuff. And, you know, so there's all these kind of everyone's looking at contingent reasons why Earth is special in the center of the universe. And I don't think that necessarily, that's you no problem, but we need to assess if we are rare, then you know, we have to, we have to cope with the possibility that maybe we are the only intelligent life form in our galaxy, but we just don't know enough.
Nick Jikomes 1:16:31
Couple other topics I'd like to hit in the time remaining. One of them is the origin of complex life. So given that life exists, you know, it took I don't remember how many billion years to go from single celled organisms to multicellular organisms? Can we think about that transition using the same framework you're using to think about the origins of life? Because I mean, I would presume that the types of molecular artifacts that a multicellular organism produces are quantifiably, more more complex than the ones that a bacteria produces, say, Do do you think about the transition from unicellular to multicellular life at all? And there's and is there anything you can say about about that transition?
Unknown Speaker 1:17:10
Yeah, I'm not as negative on it as you are. Yeah, I mean, I would, I probably shouldn't use the word quite like this, because has negative connotation connotations. But, you know, Earth might just be retarded with respect to its ability to go from single cell to multi zone. And what do I mean? I don't mean retarded and pejorative, I mean, think about it, our pressure on our temperature, required a mess, ink and ability to take in information to kind of change the way we store information in the cell. And then we then took a metabolic change as well, because we put oxygen in the atmosphere. But what about if there been oxygen in the atmosphere? What about had we already there was a natural source of oxygen, so life didn't have to evolve in the absence of oxygen. And so we are kind of there might be a wind might be quite a wide window on there. So you know, it may be that on some planets, you can get to intelligence really quickly. And other planets are just a bit slower, like I say, retarded, but I mean, that from a planetary point of view. And from an NF equals one, you know, observations, we can't say anything, or we can comment on is like, isn't it where the earth was quite happy, you know, in one domain, until it was tipped into another domain, I think the hint is this, you need a changing environment to challenge the life form for it to then kick up a level kick up a level kick up a level. So Earth was good, and that it was stable enough for life to emerge. But it was too stable for life to make the kick up, life had to actually pollute the environment for things to happen, which I think is kind of interesting. And maybe people saying, well, actually you're, you're Miss evaluating life on Earth, life on Earth is not you shouldn't be counting the IQ of life on Earth, you should be counting the ability of life to just form and cope with its environment. And maybe arguably, climate change that it's coming, everyone's worrying about is going to be another increase in our collective IQ as a species, because we might have to we have to out evolve it or our technological lead competed.
Nick Jikomes 1:19:15
Yeah, so I didn't actually think about this before, you're basically saying that you could almost think about a transition in complexity unicellular to multicellular life, say, as having an activation energy. Yeah, to borrow a concept from from chemistry and perhaps at on Earth, we actually had a very high activation energy for multicellular life simply because we didn't have oxygen other things around.
Unknown Speaker 1:19:37
Yeah, Earth was too distant. That's not used a negative connotation. Let's say Earth was a bit boring. Right? And then and so it took a while for things to happen, but maybe there are other planets are maybe smaller, have different conditions. And maybe it's the smaller planets, the less boring they get to intelligence quicker because the planet is going to burn out or something's going to happen. And those you might find clustering of technological civilizations on earth like planets that might be a little bit smaller, that have been kicked into that trajectory quicker. But, I mean, I've just made this up. But it's fun to think about, right? Because I think that we just say, Oh, it took this time on Earth, therefore, therefore, nothing, we don't know anything. All we can say is, it's, it's interesting, it took this amount of time, it could be depressing if we're demanding intelligence to be the pinnacle. But I wouldn't be down on it, I think we just have to be as open minded as possible in our search.
Nick Jikomes 1:20:31
And so I guess this is a good place to talk about the the next stage of the next step up, which is, you know, life starts. That's interesting. It's a very interesting transition. Life goes from relatively simple unicellular to multicellular, also a very interesting transition. And then at some point on Earth, you get what we would call minded life life that is aware. And it's, I'm not gonna use the word pinnacle, but its most complex. exemplar is ourselves. And I'm wondering what your general thoughts are on how deep the connection is between thinking about the problem of life's origins and thinking about the origin of consciousness. I know that, for example, I've had Terrence Deacon, on the podcast before and we didn't really get to this specifically. But someone like him would argue that understanding the origin of life is actually very deeply connected to understanding the origin of consciousness. And it's not merely a kind of metaphor. Do you think a lot about that stage of complexity and where consciousness comes from?
Unknown Speaker 1:21:34
Yes, and no, I mean, I think that maybe Terence thinks consciousness is more special than it is. I think consciousness is not really that special per se there at well, we're it isn't it isn't. So I but I would agree that I think that the same transitions and information or the same lack of understanding of physics of the new physics of chemistry and biology, that drives the origin of life is also responsible for the for consciousness. And I would say origin of life is probably a few colleagues. I think Michael Lachman has said this, and Sarah Walker and a few others said, Hey, we think that the origin of life is the easiest of the hard problems with consciousness being one of the hardest ones. So yes, I do think they're similar because there's transitions and information. Because I think that, you know, we really have no understanding about information in the world assembly is that first scraping that says, hey, actually, there is information out there that is not, doesn't have to be user dependent doesn't have to go from you as a god. It assembles itself, when the chain of events can remember what happened, it can make another series of steps, so the informations when they match chain. And if you think about it, consciousness, as a phenomena probably didn't emerge with a single individual, it occurred in a network, and we then infected each other, super important to understand that consciousness probably happened that way. And then, and that's also about then how life is literally searching space, for correlations, because all consciousness allows us to do is remember the past would be aware of the present. And imagine the future, I mean, imagining the future. It's one of the biggest hacks that biology has ever made. Because suddenly, I can imagine what would happen if I built a bridge did this direction, or built a skyscraper, or a computer program, these kinds of things that then cause material effect in the world, liberate me from just evolution, I can do many other things. And I think, from that degree, consciousness is a super important tool for life to be causal. In a non evolutionary or be a little bit above the layer of evolution, it doesn't be evolution, because it all lives on the layer of evolution, but its effect can be faster.
Nick Jikomes 1:23:57
And so it's really interesting to think about this idea that consciousness is something that we infected each other with, that there was a time when perhaps we had the all of the biological hardware, let's just say, that allows us that sets us up to have the minds we have today. But it wasn't until some kind of social structure something emerged, that, you know, what we can refer to as consciousness arose, but it arose in parallel in many locations and sort of spread from person to person almost like an actual virus. Do you think that's? Do you think that's merely a metaphor? So when people start talking about mimetics, and ideas, replicating like genes, is there something deeper than a metaphor there?
Unknown Speaker 1:24:40
Yeah, it's no it's mostly in face the mechanism. The thing is, why would a single way think about it? Why would a caveman cavewoman suddenly Oh, I'm now we're gonna think that doesn't make any sense. Caveman and cavewoman interacting and trying to oh, there's food over there. There's danger over there. I'm annoyed because I woke up today and I'm wet because it's raining because I live in salt. And, or I'm too hot, because I'm living in this I know whatever right? It consciousness had to be driven by utility, you know, these things don't just spring out and utility is communication. So communication now doesn't mean that self awareness, self awareness is always there. But consciousness, what I mean by abstraction, the ability to then start labeling things and so on, and that was kind of must have collectively emerged. And also, I think it did shape the hardware, there was a minimal hardware where you could start, and then that we selected, so the ability for us to now create memes was entirely evolved. And so I know I don't think that's loose at all, I think we need to pay attention to it. It's really important. That's why one of the things I keep saying to be about origin of life, why do we care? Well, if you want to understand where humanity is going on Earth, we need to understand the origin of life, because we don't know what life is yet. Until we understand what life is, and how the causal chain and the information flowing from that process till now, can we even begin to shape the future and say, even understand, I even tried to convince people to understand social media today and the evolution of social media, we need to understand the origin of life. One of the things I'm trying to invent is like a future Twitter or counterfactual Twitter, I'm going to make a Twitter that's basically two months older, like that's the universe in two months time, interrogate that and use it to basically go back in time and seed Twitter now and have this link to it may seem insane, but it's not. It's about understanding how at the social levels, you get acting down on the biochemistry, and that comes up again, there's a process of causation that goes in all directions, but there is one directionality, by time, it's just about layers of, of abstraction.
Nick Jikomes 1:26:45
Yeah, it's almost in some sense, easier for me to think about. So if we come back to this notion of how important selection is, it's almost easier to think about selection at this higher level of the mind because we have to communicate with each other. And there's a very natural selection process that's determined by whether or not we effectively exchange our verbal communication in order to do something. And obviously, we either do it or we don't. Earlier, you touched on something that we didn't go fully into, I don't think, which is the imposition of selection by the physical environment in sediments or the Earth's crust say that you're using to do some of your origin of life experiments. Can you talk a little bit more about the relationship between selection? Or how selection happens at the level of life's origins? And what that has to do with the physical constraints of the environment?
Unknown Speaker 1:27:35
Yeah, so that's, that is the question. I think, when we understand this, we understand consciousness, which is kind of bizarre statement to make. So really, so first of all, I should say that I have some very strange views of time in the universe. And the way that determinism works, I'm going to compact a huge amount into about three minutes, which will probably need about three zillion podcasts if you're interested at some point in the future. But the first point is, I'm a determinist. And I the universe had to be deterministic for life to even emerge. Now doesn't mean I don't believe in well, there's no free will. But that doesn't mean I don't, but I do believe there is an unwritten future. Physicists are kind of determinists, and they think the future is written. And it's not, and explain what that isn't moment. But I need determinism to work even at the quantum level, even in the quantum realm. Because there needs to be causal effect, you don't have cause and effect, you don't have selection. So that's the point number one, you have some kind of physical laws or some kind of inter interactions happen to happen that there happens to be one hour of time. So time is not merely an add on time is more fundamental than space, the beginning of the universe, that was time, that time created space. Now, let's just leave it behind, because don't need to worry about that. It just helps you understand the causal structure. So you have time creating their events happening in that time, and say, boulders bunching into one another. So let's go now to the origin of life and geology, you've got some so you've got you have the Big Bang, create stuff, stuff crystallizes into matter. Matter crystallizes into stars, stars explode, create planets, planets have inorganic stuff on them. That's all kind of determined from the, you know, from the Big Bang, right? Okay, there's obviously undetermined things. But life does something to determinate in terms of states available. This is what it really makes us really is about to fry your brain if it hasn't already, that basically the universe is relatively deterministic, but complex, but what life starts to do is to imagine itself and abstraction space. So there is like this greater possibility through selection than the universe could get. So the reason why the universe is not deterministic is because of selection. And this is why I think when you have to understand selection goes all the way back to the Big Bang. So what do I mean if you've got a series of interacting particles You could estimate what's going to happen in the future, the basis of what's happened in the past. There is no causal structure, there's just laws. But if you suddenly have selection, where that selection is kind of contained, there's a bubble of, you know, that follows around the particle that bubble selection bubble, then suddenly things become much more undetermined, because there's so many interactions, and you can then see the objects. That's just now sound. Now, let's now go to the crystal world, I've got the crystal with a military, military's just random dunk, but the crystal has an ordered face. So suddenly, this random gunk sits on the crystal and doing random interactions but makes a molecule magically, we're not magically probabilistically. But that molecule happens to be a catalyst for itself. So suddenly, a self replicating molecule gets made on that crystal randomly. And there's more stuff that comes in this molecule goes, Hey, I'm quite good at making myself I'm now making myself hey, look at you, before you know all the gunk, it's been turned to this molecule. And in that process, name, maybe the molecule makes another accident goes into another crystal. And it makes another version of itself with another atom on because hey, I've now made another one of myself. But I've got an extra asset on my head before and this carries on and carries on and carries on. Before you know it you have a molecule such complexity, high Assembly Number can't afford by chance, but there's a series of events which have created and that was what I would call a causal genetic code. And that is the thing that really kickstart life because you're in this set of adjacent spaces is really hard to get your head around. So what am I saying? I've just contradicted my my life detector. So oh, a molecule in a in a in a piece of you know, piece of gunk in a crystal replicating itself and another crystal another crystal is a is a can having a semi Assembly Number, therefore, they have caught you out that you say that's a lie that life does that. And they'll say, you see that crystal with that molecule has made itself in that crystal and a bit of genetic information, that is a minimal life form that is selection. So what is so what I'm now saying is like, whoa, assembly theory, and counting the numbers of Moloch parts isn't just about your life or not. It identifies selection. That so assembly theory is a selection detector is not a life detector. It's a selection detector. But the more selection, the more light, the more likely you have life. And that was a mind blowing moment that I kind of realized just a few weeks ago after, you know, lots of toil. So I said a lot there. But I think I've kind of addressed your question. And I think it's really important because that selection then gives rise to higher levels. And in the end abstraction and consciousness. And we now have a history of events, we don't have freewill entirely. But we are shaped by our past, which is complex. And our future, what you're going to do next, what I'm gonna do next, no one can know, because we have all this internal structure, and we're reading out it almost like two unwritten books with to read parts, the environment is one set of chapters that are reading you and you're writing it, and you're the other half. And when you get together, you have a series of you then have to decide you basically know what decisions to make. I don't know if that makes sense. Sorry, for the very long explanation.
Nick Jikomes 1:33:26
No, no, I think this is interesting. I wonder if so when we think about selection, I'm not trying to talk about it without without using the word in its own definition. But but by definition, when there's a selection process, right, you've resolved a set of many possibilities into just one. And that seems closely related to just the basic concept of information and coding, right? It's a resolution of different possibilities into one, can you maybe connect the dots there for people? And we maybe should have done this earlier? But can you just define information from an information theory perspective? For those who don't have that background?
Unknown Speaker 1:34:07
Yeah, I mean, I think there is a there's, we're in this horrible situation with information that we keep misusing it. So there's a there's a perfect triangle, I think, where we have assembly, entropy and information. So let's take this all in one, let's take the easy one entropy. Entropy just basically tells me the amount of disorder in the system or conversely, the amount of audit tells me, you know, the amount of flux and stuff that's going on with entropy is kind of like almost viewed as evidence of a power source. In fact, entropy is just telling us that time exists, and we don't need entropy in the end, but that's heretical, will get me fired and physicists that have jobs and also but entropy is kind of a fake term that we've used to cope with the fact that we have time we had time on but don't worry about that. Entropy is very useful. So stop mechanics. So now inflammation Information, what is it so information put simply, there are a number of definitions. But information is a thing that I can tell you. Okay? So I can give you a some, some root, some opposite of some something I know which when you are encounter that same circumstance, you can act differently. So let's just say I say, Hey, Nick, that you're traveling to Idaho, a certain town, it's very busy. So don't go with your car, go on foot, park your car outside. So you could have done two things, you could have said, Mom. And as I don't know that information was going to go and get stuck in a traffic jam. Or your I know this, I'm going to park outside. And now I can walk freely to everyone that is a piece of information allowed you to act differently. So information is causal. Okay, but put a bit more a bit more generically, if you take the Shannon, electrical engineering and coding information basically says, Hey, you're playing poker with me, I've just dealt you four aces, or three aces, the chances that your four players are out all the other players around you have an ace, you know, because you have three aces, that you have reduced your uncertainty in that. So information is really at its core about reduction of uncertainty. So that's a very important thing to have, but the problem of information in our universe. Without living things, there's no information. That's really kind of messed up. What I mean by that was, there's no living stuff, there's no encoding, there's no decoding. So I can't tell you something. So that's why that assembly is lower, is more primal, more fundamental than information, because assembly is in the causal chain. And then assembly allows you to build life and build objects. And then we can communicate. And then this phenomena information kicks in, what the problem we have right now as physicists are using information theory built for communicators, to look at origin of life and systems, and it's not fit for purpose, because it's meant for something else. So you have to put yourself in the causal chain, then you get assembly theory, when you're above the causal chain, you are information theory.
Nick Jikomes 1:37:23
Or this is definitely the first podcast conversation where I want to listen to this one twice after we're done once in a sober state of mind. And once not, I'm wondering if you have any non technical artifacts like a book or anything that you've written that that people might go to, if they're unfamiliar with your work so far,
Unknown Speaker 1:37:46
non technical artifacts? No, I'm not very poor at that. I do have a I do. I suppose there are a whole variety of other podcasts out there. There is also some kind of videos as inorganica, which was made many years ago, which is fairly embarrassing, but fairly descriptive about what I'm trying to do in terms of looking for life. And there's also I suppose, you know, a kind of long set of conversations I've been having in the public domain with people on Twitter, on blogs, increasingly on clubhouse about these concepts. I am starting to write more generally now I understand how to put it in such a way that so my son, I should have texted them to say Hang on one second. I'm
Unknown Speaker 1:38:43
right, come back again. So I'm talking on I'm doing increasingly lots of discussions on blogs, on Clubhouse. I'm starting to get to the point. Now I understand what I'm talking about in a more general sense. So I'm writing some more general texts. I might even write a book or two one day, but right now I'm just trying to get this triangle of ideas, like I said in entropy information assembly, right? And then on the understand all the way back, that life is not a one off. Life is driven by selection. Selection is a fundamental objective process that occurs in the universe. Selection is the way to get to information and abstraction. But it has to go through this process we don't yet understand. And that is a really fascinating because we're just at the beginning, right? I don't have all the answers. In fact, I don't have any I just have questions, but I'm more non bias look and my the way that I'm developing my theory, as I said at the beginning, is through experiment. The assembly theory I just didn't dream up one day I thought of the mass spec experiment and thought oh gosh, I can tell complex molecules taxall which is a complex drug made by a tree bark From a random molecule that I made might find by accident dead on Mars. And when I realized those two things, and I kept obsessing about it and said, Well, maybe it could naturally occur. But but maybe I could naturally, you know, flip a coin and get 20 heads in a row, how long would it take for me to do that? Or you could calculate it, say, Oh, that's not probable. Now, let me say, I can quick flick 20 heads in a row on demand, everyone would know I'm cheating. And when I realized that my colleagues when they said are, maybe you could get 20 heads in a row, they realized, actually, when they play that to themselves, that doesn't work. So I know the theories, right. And I think that what I've tried to do is to try to help NASA because the problem that we have going back to the origin of life is we have a series of arguments based on ego and narrative, a series of definitions based on ego, a narrative, and a series of, of what is the most important way to look at it based on ego and narrative, right? I mean, of course, science is based on ego and narrative. But what I wanted to do is unify people. So I decided to do one thing is to take a leaf out of high energy physics, we have the standard model. That's a theory for matter, works brilliantly. Now, with the standard model, we can calculate where we might find particles. So we do that. Now we can build a particle accelerator, you know what we went and did, we said, okay, given the Standard Model, with our calculation, and our experiment, we expect to see a peak here, here. And here. We went to did it and found it, we even found that pigs. So here's my idea. I have an idea that the origin of life or life in general requires assembly, I can calculate roughly how much assembly we need. So now I'm going to go make a robot. And now now roughly how long to look before I start seeing selection. So I mill my robot doing starting random, and it starts random and can feed itself. So it should get non random over time, and at some point should cross the threshold where I can detect assembly, and that will be the point at which we invent life in the lab, objectively demonstratively. And that's so exciting because it will happen.
Nick Jikomes 1:42:16
Lee Cronin, I think that's a great place to leave it. Thank you for joining me today.
Unknown Speaker 1:42:21
Thanks very much, Nick. It was a pleasure.