Nick Lane: Origin of Life, Evolution, Aliens, Biology, and Consciousness | Lex Fridman Podcast #318

Nick Lane 0:00 Well, the source of energy at the origin of life is the reaction between carbon dioxide and hydrogen. And amazingly, most of these reactions are exergonic. Which is to say, they release energy. This- if you have hydrogen and CO2 and you put them together in a Falcon tube and you warm it up to, say, 50 degrees centigrade, and you put in a couple of catalysts and you shake it, nothing is gonna happen. But thermodynamically, that is less stable. Two gases, hydrogen and CO2, is less stable than cells. What should happen is you get cells coming out. Why doesn't that happen is because of the kinetic barriers. It's becau- that's why you need the spark.

Lex Fridman 0:38 The following is a conversation with Nick Lane, a biochemist at University College London, and author of some of my favorite books on biology, science, and life ever written. Including his two most recent titled Transformer: The Deep Chemistry of Life and Death, and The Vital Question: Why is Life the Way It Is? This is Lex Fridman Podcast. To support it, please check out our sponsors in the description. And now, dear friends, here's Nick Lane.

Lex Fridman 1:09 Let's start with perhaps the most mysterious, the most interesting question that, uh, we little humans can ask of ourselves. How did life originate on Earth?

Nick Lane 1:20 You could, you could ask anybody working on the subject and you'll get a different answer from all of them. They will be passionately held opinions. And they're opinions grounded in science, um, but they're still really at this point, they're opinions. Because there's so much stuff to know, um, that all we can ever do is get a kind of a small slice of it, and it's the context which matters. So I can give you my answer. My answer is from a biologist's point of view. That has been missing from the equation over decades, which is, well, what does life do on Earth? What, what, why is it this way? Why is it made of cells? Why is it made of carbon? Uh, why does it, why is it powered by electrical charges on membranes? There's all these interesting questions about cells that if you then look to see, well, is there an environment on Earth, on the early Earth 4 billion years ago, that kind of matches the requirements of cells? Well, there is one. There's a very obvious one, it's basically created by whenever you have a wet rocky planet, you get these hydrothermal vents, uh, which generate, um, hydrogen gas in bucket loads, and electrical charges on kind of cell-like pores, uh, that can, that can drive the kind of chemistry that life does. So it seems so beautiful and so, so obvious, um, that I've spent the last 10 years or more trying to do experiments. It turns out to be difficult of course. Everything's more difficult than you ever thought it was going to be. But it looks, I would say, more true rather than less true over that 10-year period. I think I, I have to take a step back every now and then and think, "Hang on a minute, where is this going?" Uh, I, I'm happy it's going in a sensible direction. Uh, and, and I think then you have these other interesting dilemmas. I mean, I'm often accused of being too focused on life on Earth, too kind of narrow minded and inward looking, you might say. I, I'm, I'm talking about carbon, I'm talking about cells, and maybe you or plenty of people can say to me, "Ah, yeah. But life can be anything. I have no imagination." And maybe they're right. But unless we can say why life here is this way, and if those reasons are fundamental reasons or if they're just trivial reasons, then we can't answer that question. Um, so, so I think they're fundamental reasons, and I think we need to worry about them.

Lex Fridman 3:40 Yeah, there might be some deep truth to the puzzle here on Earth that will resonate with other puzzles elsewhere that will, um, solving this particular puzzle will give us that deeper truth. So, what, to this puzzle, you said vents, hydrogen, wet. So, chemically, what is the potion here? How important is oxygen? You wrote a book about this.

Nick Lane 4:07 Yeah. And I actually just came straight here from a conference where I was chairing a session on whether oxygen matters or not in the history of life. Of course it matters.

Lex Fridman 4:15 Yeah.

Nick Lane 4:15 Uh, but it, it matters most to the origin of life to be not there. Um, as I see it, we have this... I mean, life is made of carbon basically, primarily. Um, organic molecules with carbon-carbon bonds. And the building block, the Lego brick that we take out of the air or take out of the oceans is carbon dioxide. And to turn carbon dioxide into organic molecules, we need to strap on hydrogen. And so we need an en- and this is basically what life is doing, it's hydrogenating carbon dioxide. It's taking the hydrogen and it bubbles out of the earth in these hydrothermal vents and it sticks it on CO2. Um, and it's kind of really as simple as that. Um, a- and actually thermodynamically, there's the, the thing that I find most troubling is that you, if you do these experiments in the lab, the molecules you get are exactly the molecules that we see at the heart of biochemistry and the heart of life.

Lex Fridman 5:10 Is there something to be said about the earliest origins of that little, um, potion, that chemical process? What really is the spark there?

Nick Lane 5:24 There isn't a spark. Um, there is a continuous chemical reaction. And there is kind of a spark but it's a continuous electrical charge which helps drive that reaction.

Lex Fridman 5:37 So literally spark (laughs) ?

Nick Lane 5:39 Uh, well, the charge at least. But yes. I mean, a spark in that sense is, um, we are, we tend to think of in terms of Frankenstein. We tend to think in terms of electricity and one, one moment you zap something and it comes alive.

Lex Fridman 5:52 Mm-hmm.

Nick Lane 5:52 Uh, and what does that really mean? You've, it's come alive and now what's sustaining it? Well (laughs) , we are sustained by oxygen, by this continuous chemical reaction. Uh, and if you put a plastic bag on your head then you got a minute or something before, uh, it's all over.

Lex Fridman 6:07 So it's some way of being able to leverage a source of energy?

Nick Lane 6:11 Well, the source of energy at the origin of life is the reaction between carbon dioxide and hydrogen, and amazingly most of these reactions are...... exergonic, which is to say they release energy. There's-- if you have hydrogen and CO2 and you put them together in a Falcon tube and you warm it up to, say, 50 degrees centigrade and you put in a couple of catalysts and you shake it, nothing's gonna happen. But thermodynamically, that is less stable, two gases, hydrogen and CO2, is less stable than cells. What should happen is you get cells coming out. Um, uh, uh, so why doesn't that happen is because of the kinetic barriers. It's bec- that's where you need the spark.

Lex Fridman 6:50 Is it possible that life originated multiple times on Earth? The way you describe it, you make it sound so easy.

Nick Lane 6:57 (laughs) There's a long distance to go from the s- first bits of prebiotic chemistry to, say, molecular machines like ribosomes.

Lex Fridman 7:05 Is that the first thing that you would say is life? Like, if I introduce you, to- the two of you to- at a party, you would say that's a living thing?

Nick Lane 7:15 I would say as soon as we introduce genes, information, into systems that are growing anyway, so I, I would s- I would talk about growing protocells. As soon as we inf- in- introduce even random bits of information into, into there, uh, I'm thinking about RNA molecules, for example, doesn't have to have any information in here, it can be completely random sequence. But if it's introduced into a system which is in any case growing and doubling itself and reproducing itself, then any changes in that sequence that a- allow it to do so better or worse are now selected by perfectly normal natural selection.

Lex Fridman 7:51 But the system...

Nick Lane 7:52 So that's when it becomes alive, to my mind.

Lex Fridman 7:54 ... that's encompassed into, like, um, uh, an object that keeps information and evolves that information over time, changes that information over time...

Nick Lane 8:06 Yes, exactly.

Lex Fridman 8:06 ... in response to the environment.

Nick Lane 8:07 So it's always part of a cell system from the very beginning.

Lex Fridman 8:11 So does your sense that it started only once because it's difficult, or is it possible it started at multiple locations on Earth?

Nick Lane 8:18 It's possible it started multiple occasions. Um, there's two provisos to that. One of them is oxygen makes it impossible, really, for life to start. So as soon as we've got oxygen in the atmosphere, then life isn't gonna keep starting over. So I, I often get asked by people, you know, "Why, why can't we have life starting? If it's so easy, why can't life start in these vents now?" And the answer is, i- if you want, if you want hydrogen to react with CO2 and there's oxygen there, hydrogen reacts with oxygen instead. It just, you know, you, you're getting explosive reaction that way as rocket fuel. So it's never gonna happen. But the other, for, for the origin of life earlier than that, all we know is that there's a single common ancestor for all of life. There could've been multiple origins and they all just disappeared. Um, but there's a very interesting deep split in life between bacteria and what are called archaea, which look just the same as bacteria. Um, and they're not quite as diverse, but nearly, and they are v- very different in their biochemistry. And so any explanation for the origin of life has to a- account as well for why they're so different and yet so similar. And that makes me think that life probably did arise only once.

Lex Fridman 9:29 Can you describe the difference that's interesting there? What, well, how they're similar, how they're different?

Nick Lane 9:34 Well, they're different in, uh, in their membranes primarily. They're different in things like DNA replication. They use completely different enzymes and, and the genes behind it for replicating DNA.

Lex Fridman 9:44 So they both have membranes, both have DNA replication.

Nick Lane 9:48 Yes.

Lex Fridman 9:48 The process of that is different.

Nick Lane 9:50 They have D- they both have DNA, the genetic code is identical in them both, the way in which it's, uh, transcribed into RNA, into the copy of, uh, of a gene, and the way that that's then translated into a protein, that's all basically the same in both these groups. So they clearly share a common ancestor. It's just that they're different in fundamental ways as well. And if you think about, well, what kind of processors could drive that divergence very early on, um, I can think about it in terms of membranes, in terms of the e- electrical charges on membranes. And it's that that makes me think that, uh, there was probably, there were probably many unsuccessful attempts and only one really successful attempt.

Lex Fridman 10:30 Can you explain why that divergence makes you think there's one ance- uh, one common ancestor? Okay, can you describe that intuition? I'm a little bit unclear about-

Nick Lane 10:39 Yeah.

Lex Fridman 10:39 ... why the diver- like the leap from the divergence means there's one. It d- do you mean like the divergence indicates that there was a big invention at, at that time-

Nick Lane 10:50 Y- yes.

Lex Fridman 10:50 ... from one source?

Nick Lane 10:51 If, if it was, if, if you'd got, uh, as I imagine it, you have a, a common ancestor living in a hydrothermal vent. Let's say there are, you know, millions of vents and millions of potential common ancestors living in all of those vents, but only one of them makes it out first. Then you could imagine that that cell is then gonna kind of take over the world and, and, and wipe out everything else. And so you, what you would see would be a single common ancestor for all of life. But with, you know, lots, lots of different vent systems all kind of vying to create the first life forms, you might say.

Lex Fridman 11:25 So this thing is a cell, a single-celled organism.

Nick Lane 11:27 Eh, well, we're do- we're d- we're always talking about populations of cells, but yes. These are single-celled organisms.

Lex Fridman 11:33 Well, but the, the fundamental life form is a single cell, right? So like, or (laughs) so they're, they're always together but they're alone together. (laughs)

Nick Lane 11:44 Yeah. I mean-

Lex Fridman 11:44 There's a machinery in each one individual component-

Nick Lane 11:47 Yes.

Lex Fridman 11:47 ... that if left by itself would still op- work, right?

Nick Lane 11:50 Yes, yes, yes. It's the unit of selection is a single cell, but selection operates over generations and changes over generations in populations of cells. So it would be impossible to say that a cell is the unit of selection in the sense that you, unless you have a population, you can't evolve, you can't change.

Lex Fridman 12:07 Right. But there was one Chuck Norris, it's an American reference-

Nick Lane 12:13 Yeah.

Lex Fridman 12:14 ... uh, cell that made it out of the vents, right? Or like the first one.

Nick Lane 12:19 So imagine then there's one cell gets out and it takes over the world.

Lex Fridman 12:23 It gets out in the water, it's like floating around.

Nick Lane 12:25 Well, deep in the ocean somewhere.

Lex Fridman 12:27 Yeah.

Nick Lane 12:27 ... but actually, two cells got out. Um, and they appear to have got out from the same vent-

Lex Fridman 12:35 Mm-hmm.

Nick Lane 12:35 ... because they both share the same code and everything else. So, unless all the, you know, we've got a million different common ancestors in, in, in all these different vents. So, either they all have the same code and two cells spontaneously emerge from different places, or two s- two different cells, fundamentally different cells, came from the same place. So, either way, one of the constraints that say, not just one came out, or not half a million came out, but two (laughs) came out. That's kind of a bit strange. Uh, so how did they come out? Well, they come out because what you're doing inside a vent is you're relying on the electrical charges down there to power this reaction between hydrogen and CO2 to make yourself grow. And when you leave the vent, you've got to do that yourself. You've got to power up your own membrane. And so the question is, well, how do you power up your own membrane? Uh, and the answer is, well, you need to pump. You need to pump ions to give an electrical charge on the membrane. So, what do the pumps look like? Well, the pumps look different in these two groups. It's as if they, they both emerged from a common ancestor, and as soon as you've got that ancestor, things move very quickly, um, and, and, and divergently. Why does the DNA replication look different? Well, it's joined to the membrane. The membranes are different. The DNA replication's different because it's joined to a different kind of membrane. So, there's interesting, you know, this, this is detail you may say, but it's also fundamental because it's about the two big divergent groups of life on Earth that seem to have diverged really early on.

Lex Fridman 14:03 It all started from one organism, and then that organism started replicating the heck out of itself with some mutation of the DNA? So like, there's some, um, there's a competition through the process of evolution. They're not like trying to beat each other up.

Nick Lane 14:21 (laughs)

Lex Fridman 14:21 They're just, uh, they're just trying to live more-

Nick Lane 14:23 They are just replicators.

Lex Fridman 14:25 Yeah. Well-

Nick Lane 14:26 Uh-

Lex Fridman 14:26 ... you know, let's not minimize their-

Nick Lane 14:28 Yeah. Well-

Lex Fridman 14:28 They're, they're t- trying to chill. They're trying to relax-

Nick Lane 14:31 Yeah.

Lex Fridman 14:31 ... up in the ... There's no, but there's no sense of trying to survive. They're replicating-

Nick Lane 14:36 I mean, there's no sense in which they're trying to do anything. They're just a, kind of an outgrowth of the Earth, you might say.

Lex Fridman 14:42 Of course the aliens would describe us humans in that same way. (laughs)

Nick Lane 14:46 (laughs) They, they might be right.

Lex Fridman 14:47 This primitive life is just, is just ants that are hairless-

Nick Lane 14:52 (laughs)

Lex Fridman 14:52 ... par- mostly hairless.

Nick Lane 14:53 Overgrown ants.

Lex Fridman 14:54 Overgrown ants. (laughs) Okay.

Lex Fridman 14:56 Um, what do you think about the idea of, uh, panspermia that the theory that life did not originate on Earth and was planted here from outer space? Or pseudopanspermia, which is like the basic ingredients, the magic that you mentioned was planted here from elsewhere in space?

Nick Lane 15:15 I don't find them helpful. That's not to say they're wrong. Uh, so, so pseudotranspermia, the idea that, you know, the chemicals, the amino acids, the nucleotides are being delivered from space. Well, we know that happens. It's unequivocal. Uh, they're delivered on meteorites, comets, and so on. Um, so what do they do next? That's, to me, the question. And what they do is they stock a soup. Like, presumably they land in a pond or in an ocean, or wherever they land, and then you end up with a, you know, a best possible case scenario is you end up with a soup of nucleotides and amino acids, and then you have to say, "So now what happens?" And the answer is, "Oh, well they have to go bloop (laughs) become alive."

Lex Fridman 15:50 Mm-hmm.

Nick Lane 15:50 So, how did they do that? You may as well say that a miracle happened. Um, I don't believe in soup. Um, I th- I think what we have in a vent is a continuous conversion, a continuous growth, a continuous reaction, a continuous converting, a flow of molecules into m- more of yourself, you might say, even if it's a small bit. So you, you've got, you've got a kind of continuous self-organization and growth from the very beginning.

Lex Fridman 16:14 What-

Nick Lane 16:14 You never have that in a soup.

Lex Fridman 16:17 Isn't the entire universe and living organisms in the universe, isn't it just, uh, soup all the way down? Isn't it all soup?

Nick Lane 16:25 No. No. I mean, soup almost by definition doesn't have a structure.

Lex Fridman 16:29 But soup is a collection of ingredients that are like randomly interacting-

Nick Lane 16:34 Yeah, but they're not random. They're not. I mean, they, they, the, we have chemistry going on here. We have membranes-

Lex Fridman 16:39 So there-

Nick Lane 16:39 ... forming, which are, which are, you know, effective-

Lex Fridman 16:41 There's a process going on.

Nick Lane 16:41 ... oil/water interactions. Uh, i-

Lex Fridman 16:43 Okay. S- it feels like there's a direction to a proc- like a directed process.

Nick Lane 16:47 There are d- there are directions to processes. Yeah. Uh, and if you are com- if you're starting with CO2 and you've got two reactive fluids being brought together and they, they react, what are they gonna make? Well, they, they make carboxylic acids, which include the fatty acids that make up the cell membranes and, and they form directly into bilayer membranes. They form like soap bubbles. It's, it's spontaneous organization caused by the nature of the molecules. And, and those things are capable of growing and are capable, in effect, of being selected. Even before there are genes, we have th- so we have a lot of order. And that order is coming from thermodynamics. And the thermodynamics, i- is always about increasing the entropy of the universe, but if you have, if you have oil and water and they're separating, you're increasing the entropy of the universe, even though you've got some order, which is the soap and the water are not, not miscible. Now, n- uh, to come back to your first question about, um, panspermia properly, um, that just pushes the question somewhere else. That just, even if it's true, maybe life did start on Earth by panspermia, but, but so what are the principles that govern the emergence of life on any planet? We, we, it's an assumption that life started here, and it's an assumption that it, you know, it started in a hydrothermal vent or it started in a terrestrial geothermal system. The question is can we work out a testable sequence of events that would lead from one-

Lex Fridman 18:09 Yeah.

Nick Lane 18:09 ... to the other one and then test it and see if there's any truth in it or not? With panspermia, you can't do any of that.

Lex Fridman 18:15 But the, the fundamental question of panspermia is do we have the machine here on Earth to build life? I- is-

Nick Lane 18:23 Not yet.

Lex Fridman 18:23 ... the vents enough? I- is oxygen and hydrogen...... and whatever the heck else we want and some source of energy and heat. Is that enough to build life-

Nick Lane 18:36 Yes.

Lex Fridman 18:36 ... or, or well, that's-

Nick Lane 18:38 (laughs)

Lex Fridman 18:39 ... (laughs) of course, you would say that as a human-

Nick Lane 18:41 Yeah.

Lex Fridman 18:42 ... uh, but there could be aliens right now chuckling at that idea. Maybe you need some special, um, special sauce.

Nick Lane 18:50 Uh, well-

Lex Fridman 18:50 Special elsewhere sauce.

Nick Lane 18:52 ... yes. And, and-

Lex Fridman 18:52 So your sense is we have everything here.

Nick Lane 18:54 I mean, this is precisely the, the, the question. So I, I, I like to, when I'm, when I'm talking in schools, I like to start out with the idea of w- we make, we can make a time machine.

Lex Fridman 19:03 Yes.

Nick Lane 19:03 We go back four billion years and we go to these environments that people talk about. We go to a deep sea hydrothermal vent. We go to a, a kind of Yellowstone Park type, uh, place environment and we find some slime that looks like it can... We can test it. It's made of organic molecules. It's got a structure which is not obviously cells, but you know, it's, i- i- i- is this a stepping stone on the way to life or not?

Lex Fridman 19:26 Yeah.

Nick Lane 19:27 How do we know? Unless we've got an intellectual framework that says that this is, this is a stepping stone and that's not a step, you know, we'd never know. We wouldn't know which environment to go to-

Lex Fridman 19:36 Yes.

Nick Lane 19:36 ... what to look for, how to say this. So all we can ever hope for, because we're never gonna build that time machine, is to have an intellectual framework that can explain step by step, experiment by experiment how we go from a sterile inorganic planet to living cells as we know them. And in that framework, every time you have a choice, it could be this way or it could be that way or, you know, there's lots of possible forks down that road. Um, did it have to be that way? Could it have been the other way and would that have given you life with very different properties?

Lex Fridman 20:07 Mm-hmm.

Nick Lane 20:08 Um, uh, and so if you, if you come up with a... You know, it's a long hypothesis because as I say, we're going from really simple prebiotic chemistry all the way through to genes and molecular machines. That's a long, long pathway and nobody in the field would agree on the order in which these things happened. Which is not a bad thing because it means that you have to go out and do some experiments and try and demonstrate that it's possible or not possible.

Lex Fridman 20:29 It's

Lex Fridman 20:30 so freaking amazing-

Nick Lane 20:34 That it-

Lex Fridman 20:34 ... that it happened though. It feels like there's a direction to the thing. Can you try to answer from a framework perspective of what is life? So you said there's some order and yet there's complexity. So it's not perfectly ordered. It's not boring.

Nick Lane 21:00 Mm-hmm.

Lex Fridman 21:00 There's still some fun in it and it also feels like the processes have a direction through the selection mechanism. They seem to be building something always better, always improving. I mean, maybe it's-

Nick Lane 21:15 I mean, that's a perception.

Lex Fridman 21:16 That's our romantization of things are always better. (laughs) Things are getting better, we'd like to believe that.

Nick Lane 21:22 I mean, you think about the world from the point of view of bacteria and bacteria are the first things to emerge-

Lex Fridman 21:27 Yeah.

Nick Lane 21:28 ... from whatever environment they came from and they dominated the planet very, very quickly and they haven't really changed. Four billion years later, they look exactly the same.

Lex Fridman 21:36 So about four billion years ago, bacteria started to, to really run the show.

Nick Lane 21:42 Yeah. Yeah.

Lex Fridman 21:42 And then nothing happened for a while?

Nick Lane 21:44 Nothing happened for two billion years.

Lex Fridman 21:46 Yeah.

Nick Lane 21:47 Then after two billion years, we see another single event origin, if you like, of, of our own type of cell, the eukaryotic cell. So cells with a nucleus and lots of stuff going on inside. Another singular origin, it only happened once in the history of life on Earth. Maybe it happened multiple times and there's no evidence, everything just disappeared. But we have to at least take it seriously that there's something that stops bacteria from becoming more complex, because they didn't. You know, that's a fact that they, they emerged four billion years ago and something happened two billion years ago, but the bacteria themselves didn't change. They remain bacterial. So there is no trajectory, necessary trajectory towards great complexity in human beings at the end of it. It's very easy to imagine that without photosynthesis arising or without eukaryotes arising, that a planet could be full of bacteria and nothing else.

Lex Fridman 22:36 Okay. We'll get to that 'cause that's a brilliant invention and there's a few brilliant invention along the way. But what is life? If you were to show up on Earth but to take that time machine and you said, asking yourself the question, "Is this a stepping stone towards life?"

Nick Lane 22:52 Hmm.

Lex Fridman 22:52 As you step along, when you see the early bacteria, how would you know it's life? Is... And then-

Nick Lane 22:59 Yeah.

Lex Fridman 23:00 This is really an important question when you go to other planets and look for life. Like what, uh, what is the framework of telling the difference between a rock and a bacteria?

Nick Lane 23:12 I mean, the question's kind of both impossible to answer and trivial at the same time and I don't like to answer it because I don't think there is an answer. I think we're trying to describe-

Lex Fridman 23:20 That's the most fun question.

Nick Lane 23:21 ... the process that's-

Lex Fridman 23:22 What do you mean there's no answer? Oh, so-

Nick Lane 23:23 No, there is no answer. I mean, there's, there's lots out there, at least 40 or 50 different definitions-

Lex Fridman 23:27 Yeah.

Nick Lane 23:27 ... of life out there and most of them are, well-

Lex Fridman 23:31 Not convincing.

Nick Lane 23:32 ... obviou- ob- obviously bad in one way or another.

Lex Fridman 23:33 (laughs) Uh-

Nick Lane 23:36 I mean, there's, there's free... I, I, I can never remember the, the exact words that people use but there's a NASA, uh, working definition of life-

Lex Fridman 23:43 Mm-hmm.

Nick Lane 23:43 ... uh, which more or less says a, a, a, a system which is capable of, uh, of, of, uh, self-sustaining system capable of evolution or something along those lines. And I immediately have a problem with the word self-sustaining because it's sustained by the environment and, and, you know, I, I know what they're getting at, I know what they're trying to say but, but I, I pick a hole in that. And there's, you know, there's always wags who say, but it, you know, by that definition, a rabbit is not alive. Only a pair of rabbits would be (laughs) alive because a single rabbit is incapable of copying itself. There are all kinds of pedantic, s- s- silly but also important objections to any hypothesis. The, the real question is what, what is... You know, we can argue all day or people do argue all day about is, is a virus alive or not? And it depends on the content. Bi- most biologists could not agree abo- about that. So then what about a jumping gene, a retroelement or something like this, even simpler than a virus but it's capable of-...converting its environment into a copy of itself.

Lex Fridman 24:42 Mm-hmm.

Nick Lane 24:42 Um, and, and that's about as close... This is not a definition, but this is a, kind of a description of life, is that it's, it's able to parasitize the environment, and that goes for plants as well as animals and bacteria and viruses, um, to make a, a f- a, a relatively exact copy of themselves, informationally exact copy of themselves.

Lex Fridman 25:04 By the way, it doesn't really have to be a copy of itself, right? It just has to be... You have to create something that's interesting.

Nick Lane 25:13 Ah.

Lex Fridman 25:13 Like, we... Uh, the way evolution is... So it is extremely powerful process of evolution, which is basically make a copy of yourself and sometimes mess up-

Nick Lane 25:23 Yes.

Lex Fridman 25:23 ...a little bit.

Nick Lane 25:24 Absolutely.

Lex Fridman 25:24 Okay! That seems to work really well. I wonder if it's possible to-

Nick Lane 25:28 Mess up big time.

Lex Fridman 25:29 ...mess up big time as a standard, as the default.

Nick Lane 25:32 Ah, it's called the hopeful monster and, uh, you know, there's, there's, there's, there's-

Lex Fridman 25:34 It doesn't work?

Nick Lane 25:36 In principle, it can. Actually, it turns out... I, I would say that this is due reemergence. There's, uh, there's some amazing work from Michael Levin, I don't know if you came across him, but, uh, you... If you haven't interviewed him, you should interview him-

Lex Fridman 25:48 Yeah. Uh, yeah, in Boston.

Nick Lane 25:50 ...about... Yeah, yeah.

Lex Fridman 25:50 I'm, uh, uh, talking to him in a few days.

Nick Lane 25:53 Oh, fantastic!

Lex Fridman 25:54 (laughs)

Nick Lane 25:56 (laughs)

Lex Fridman 25:56 So I mentioned of-

Nick Lane 25:57 Yeah.

Lex Fridman 25:58 There's two people that-

Nick Lane 25:59 So he's-

Lex Fridman 25:59 ...Andre... if I may mention. Uh, Andre Kapathy is a friend who's really admired in the AI community, said, "You absolutely must talk to, to Michael and to Nick." This is so... So this... Of course, I'm a huge fan of yours, so I'm really fortunate that we can actually make this happen. Anyway, you were saying?

Nick Lane 26:16 Well, M- Michael Levin is doing amazing work, uh, basically about the way in which electrical fields control development. Um, and he's done some work with planarian worms, so flatworms, where... He'll tell you all about this, so I won't say any more than the minimum, but basically you can cut their head off and they'll redevelop a different... A, a, a n- a new head. But the head that they develop depends, if you knock out just one, um, one, one, one, one ion pump in a membrane, so you change the electrical circuitry just a little bit, you can come up with a completely different head. It can be a head which is similar to those that diverged 150 million years ago or it can be a head which no one's ever seen before, a different kind of, of head. Um, now that is really, you might say, a hopeful monster. This is a, a kind of leap into a different direction. The only question for natural selection is, does it work? Is the change itself feasible as a single change? And the answer is yes, it's just a small change to a single gene. And the second thing is it gives rise to a completely different morphology. Does it work? And if it works, that can easily be a, a, you know, a sh- a shift. It... But for it to be a speciation, for it to, to continue, for it to, to, to give rise to a different morphology over time, then it has to be perpetuated. So that shift, that change in the... In, in, in that one gene has to work well enough that it is selected and, and, and it goes on.

Lex Fridman 27:41 And copied enough times-

Nick Lane 27:42 Yeah, yeah.

Lex Fridman 27:42 ...to where you can really test it and...

Nick Lane 27:44 So the likelihood, it would, it would be lost, but, but there will be some occasions where it survives. And yes, the, the idea that we can have sudden, fairly abrupt changes in evolution, I think, is time for rebirth.

Lex Fridman 27:55 What about this idea that kind of trying to mathematize a definition of life and saying how many steps, the shortest amount of steps it takes to build the thing, almost like an engineering view of it. Uh, do you find that at all compelling?

Nick Lane 28:10 Ah! I like that view, um, because I, I think that, in a sense, that's not very far away from what i- wha- wha- what a hypothesis needs to do to be a testable hypothesis for the origin of life. You need to spell out, "Here's, here's each step. Uh, and here's the experiment to do for each step." The idea that we can do it in the lab, some people say, "Oh, we'll have f- you know, we'll have created life within five years," but, you know, ask them what they mean by life. Um, we have a planet four billion years ago with these vent systems across the entire surface of the planet and, and w- we have millions of years if we want it. I have a feeling that we're not talking about millions of years. I have a feeling we're talking about, you know, maybe millions of nanoseconds or picoseconds. We're talking about chemistry, which is happening quickly. Um, but we still need to constrain those steps, but we've got a hu- you know, a planet, uh, doing similar chemistry. You asked about a trajectory. The trajectory is the planetary trajectory. The planet has properties. It's basically, it's got a lot of iron at the center of it. It's got a lot of electrons at the center of it. It's more oxidized on the outside, partly because of the sun and partly because th- the heat of volcanoes puts out oxidized gases. So, uh, uh, the planet is a battery, it's a giant battery. Um, and we have a, a flow of electrons going from inside to outside in these hydrothermal vents, and that's the same topology that a cell has. A cell is basically just a m- a micro version of the planet. Um, and it's... Uh, there is a trajectory in all of that and, and there's an inevitability that certain types of chemical reaction are going to be favored over others. And there's an inevitability in, in what happens in water, the chemistry that happens in water. Some, some will be miscible with water and will form membranes and will form insoluble structures and, uh, you know, water's a... Nobody really understands water very well. Um, and it's, uh, it- it's another big question. For, for experiments on the origin of life, what do you put it in? (laughs)

Lex Fridman 30:03 Mm-hmm.

Nick Lane 30:04 What kind of structure do we want to induce in this water? Because the last thing is likely to be, is just kind of bulk, bulk water.

Lex Fridman 30:11 Uh, how fundamental is water to life, would you say?

Nick Lane 30:14 I would say pretty fundamental. Um, I wouldn't like to say it's impossible for life to start any other way, uh, but water is everywhere. Water's extremely good at what it does.

Lex Fridman 30:27 (laughs)

Nick Lane 30:27 And, and carbon, carbon works in water especially well. So those things... And carbon is everywhere. So those things together make me think probabilistically, if we found 1000 life forms, 995 of them would be carbon-based and living in water.

Lex Fridman 30:42 Now, the reverse question. If you found a puddle of water elsewhere, and some carbon-... no, just a puddle of water.

Nick Lane 30:49 (laughs)

Lex Fridman 30:50 Is a puddle of water a pretty damn good indication that life has, is, either exists here or has once existed here?

Nick Lane 31:01 No.

Lex Fridman 31:02 So, it doesn't work the other way?

Nick Lane 31:05 I think you need a living planet. You need a planet which is-

Lex Fridman 31:08 Condition.

Nick Lane 31:08 ... capable of turning over its surface. It needs to be a planet with water, it needs to be capable of, of, uh, of, of bringing those electrons from inside to the outside. It needs to turn over its surface, it needs to make that water work and turn it into hydrogen. So I think you need a living planet. But once you've got the living planet, I think the rest of it, uh, is kind of thermodynamics all the way.

Lex Fridman 31:29 So if you were to run Earth over a million times, up to this point, maybe beyond, to the end. Let's run it to the end. Uh, what is the, uh, how much variety is there? You kind of spoke to this trajectory that the environment dictates like chemically, I don't know in which other way, um, spiritually? (laughs)

Nick Lane 31:54 (laughs)

Lex Fridman 31:54 Like, dictates kind of the direction of this giant machine that seems, uh, chaotic, but it does seem to have order in the steps it's taking. Uh, how much, how often will life, how, how often will bacteria emerge, how often will something like humans emerge, how much variety do you think there would be?

Nick Lane 32:15 I think at the level of bacteria, not much variety. I think we would get, this is, how many times did you say you want to run it? A million times?

Lex Fridman 32:24 A million.

Nick Lane 32:24 Um, I, I would say at least a few 100,000 will get bacteria again.

Lex Fridman 32:28 Oh, wow.

Nick Lane 32:28 Um-

Lex Fridman 32:29 Nice.

Nick Lane 32:29 ... because I, I think there's some level of inevitability that a wet, rocky planet will give rise through, through the same processes-

Lex Fridman 32:36 Mm-hmm.

Nick Lane 32:36 ... to something very e- clo- I, I think I, I, this is not something I'd have thought a few years ago, but, uh, we're working with a, a PhD student of mine, Stuart Harrison, he's been thinking about the genetic code and we've just been publishing on, on, on that. Um, there are patterns that you can discern in the co- or he has discerned in the code, that if you, if you think about them in terms of we start with CO₂ and hydrogen and th- these are the first steps of biochemistry, you come up with a code which is very similar to the code that we see. So it wouldn't surprise me any longer if we found life on Mars and it had a genetic code that was not very different to the genetic code that we have here-

Lex Fridman 33:11 Oh, wow.

Nick Lane 33:11 ... without it just being transferred across. There's-

Lex Fridman 33:13 That's really promising.

Nick Lane 33:14 ... some inevitability about the whole of the beginnings of life, i- in my view.

Lex Fridman 33:18 That's really promising because if the basic chemistry is tightly linked to the genetic code, that means w- we can interact with other life if it exists out there.

Nick Lane 33:30 Uh, well, that's potentially the case, yes.

Lex Fridman 33:32 That's, that's really exciting if that's, if that's the case. Okay. But then bacteria-

Nick Lane 33:35 But we, we, we've got then, we've got bacteria.

Lex Fridman 33:37 Yeah.

Nick Lane 33:38 Um, how easy is photosynthesis? Much harder, I would say.

Lex Fridman 33:44 Let's actually go there. Let's, let's go through the inventions.

Nick Lane 33:47 Yeah.

Lex Fridman 33:48 Um, what is photosynthesis? And why is it hard?

Nick Lane 33:52 Well, there are different forms. I mean, basically, you're taking hydrogen and you're sticking it onto CO₂ and it's powered by the sun. Question is where are you taking the hydrogen from? And in photosynthesis that we know in plants, it's coming from water. So you're using the power of the sun to split water, take out the hydrogen, stick it onto CO₂ and the oxygen is a waste product and you just throw it out, throw it away. So it's a, you know, the single greatest planetary pollution event in the whole history of, of, of, of the Earth.

Lex Fridman 34:21 The pollutant being oxygen?

Nick Lane 34:22 Yes. Yeah. It also made possible animals. You can't have large, active animals without an oxygenated atmosphere. At least not, not in the sense that we know on Earth.

Lex Fridman 34:33 So that's a really big invention in the history of Earth?

Nick Lane 34:35 Huge invention. Yes. And it happened once. There's a few things that happen once on Earth and, you know, you're always stuck with this problem, is it did, once it happened, did it become so good so quickly that it precluded the, the same thing happening ever again? Or are there other reasons? And we really have to look at each one in turn thinking, "Well, why, why, what's, what's, why did it only happen once?" In this case, it's really difficult to split water. It requires a lot of power and that power you're effectively separating charge across a membrane. And the way in which you do it, if it doesn't all rush back and, and, and kind of cause an explosion right at the site, requires really careful wiring. Um, and that wiring, it can't be easy to get it right because, you know, (laughs) the plants that we see around us, they have chloroplasts. Those chloroplasts were cyanobacteria once. Those cyanobacteria are the only group of bacteria that can do that type of photosynthesis. So, there's plenty of opportunity, but-

Lex Fridman 35:28 So not even many bacteria. So who, who invented photosynthesis? That-

Nick Lane 35:32 The cyanobacteria or their ancestors.

Lex Fridman 35:34 And there's not many, um-

Nick Lane 35:36 No other bacteria can do what's called oxygenic photosynthesis. Lots of other bacteria can split fr- I mean, you can take your, your hydrogen from somewhere else. You can take it from hydrogen sulfide bubbling out of a hydrothermal vent. Grab your two hydrogens, the sulfur is the waste, now.

Lex Fridman 35:51 Yeah.

Nick Lane 35:51 Um, you can do it from iron. You can take electrons... So the early oceans were probably full of iron. You can take an electron from ferrous iron, so iron 2+ and make it iron 3+.

Lex Fridman 36:01 Mm-hmm.

Nick Lane 36:01 Which now precipitates as rust. Uh, and you take a, a, a proton from the, the acidic, early ocean, stick it there, now you've got a hydrogen atom. Stick it onto CO₂, you've just done the trick. The trouble is, you bury yourself in rusty iron. And with sulfur, you can bury yourself in sulfur. One of the reasons oxygenic photosynthesis is so much better is that the waste product is oxygen, which just bubbles away.

Lex Fridman 36:26 That seems like extremely unlikely and it's extremely essential for the evolution of complex organisms because of all the oxygen.

Nick Lane 36:36 Yeah.

Lex Fridman 36:36 You could do this.

Nick Lane 36:36 And that didn't accumulate quickly either.

Lex Fridman 36:39 So it's converting, what is it? It's converting energy from the sun and the resource of water into the resource needed for animals?

Nick Lane 36:50 ... both resources needed for animals. We need to eat and we need to burn the food. And the, w- we're eating plants, um, which are getting their energy from the sun and w- we're burning it with their waste products, which is the oxygen. So there's a lot of, kind of circularity in that. But with- with- with- without an oxygenated planet, you couldn't really have, um, predation. You- you- you don't... You- you can have animals but you can't really have animals that go around and eat each other. You can't have ecosystems as we

Nick Lane 37:19 know them.

Lex Fridman 37:19 Well, let's actually step back. What about eukaryotic versus prokaryotic cells, prokaryotes? What, how big, wh- what are each of those and how big of an invention is that?

Nick Lane 37:31 I personally think that's the single biggest invention in the whole history of life.

Lex Fridman 37:34 Exciting. (laughs) So what- what are they? Can you explain?

Nick Lane 37:37 Yeah. So- so- so I- I mentioned bacteria and archaea. These are both prokaryotes. Um, they're basically small cells that don't have a nucleus. If you look at them under a microscope, you don't see much going on. If you look at them under a super-resolution microscope, then they're fantastically complex. Uh, in terms of their molecular machinery, they're amazing. In terms of their morphological appearance under a microscope, they're really small, um, and- and really simple. The earliest life that we can physically see on the planet are stromatolites which are made by things like cyanobacteria and- and- and they're large super structures. Effectively biofilms plated on top of each other, uh, and- and- and you end up with quite- quite large structures that you can see in the fossil record.

Lex Fridman 38:19 Mm-hmm.

Nick Lane 38:19 But they- they don't... They never came up with animals. They never came up with plants. They- they came up with multi-cellular things, filamentous cyanobacteria, for example. They're just long, you know, strings of cells. But the origin of the eukaryotic cell seems to have been what's called an endosymbiosis. So one cell gets inside another cell. Uh, and I think that that's transformed the energetic possibilities of life. So what we end up with is a kind of, uh, supercharged cell which can have a much larger nucleus with many more genes, all supported... If you think about it, you could think about it as a- as multi-bacterial power without the overhead. So you've got a- you've got a cell and it's got bacteria living in it, and those bacteria are providing it with the energy currency it needs. But each bacterium has a genome of its own which costs a fair amount of energy to- to express, to, uh, to kind of turn over and convert into proteins and so on. What the mitochondria did, which are these power packs in our own cells, they were bacteria once and they threw away virtually all their genes. They've only got a few left.

Lex Fridman 39:25 So mitochondria is, like you said, is the bacteria that got inside a cell-

Nick Lane 39:29 Yeah.

Lex Fridman 39:30 ... and then threw away all this stuff it doesn't need to survive inside the cell, and then kept what?

Nick Lane 39:35 So what we end up with... So it keeps always a handful of genes, in our own case, 37 genes.

Lex Fridman 39:40 Mm-hmm.

Nick Lane 39:41 Um, but there's- there's a few protists which are single-celled things that have got as many as 70 or 80 genes. So they, it- it's not always the same but it's always a small number. Um, and y- you can think of it as a pared down power pack whe- where the control unit is really being, has been, uh, kind of pared down to almost nothing. So you're putting out the same power but the- the investment in- in the overheads is really pared down. That means that you can support a much larger nuclear genome, so we've gone up in the number of genes but also the- the amount of power you have to convert those genes into proteins. We've gone up about four-fold in the number of genes. But in terms of the- the size of genomes and your ability to- to- to make the building blocks, make the proteins, we've gone up 100,000 fold or more. So it's huge step change in the possibilities of evolution. Um, and- and it's interesting then that the only- the only two occasions that complex life has arisen on earth, plants and animals-

Lex Fridman 40:37 Mm-hmm.

Nick Lane 40:37 ... uh, fungi you could say are- are- are complex as well but they don't form such complex morphology as- as plants and animals, start with a single cell. They start with an oocyte and a sperm fused together to make a zygote. So we start development with a single cell, and all the cells in the organism have identical DNA, and you switch off in- in the brain, you switch off these genes and you switch on those genes. In the liver, you switch off those and you switch on a different set. And the standard evolutionary explanation for that is that you've, you know, you're restricting conflict. You don't have a load of genetically i- different cells that are all fighting each other. Um, and- and so it- it works. The trouble with bacteria is they form these biofilms and they're all genetically different and- and effectively, they're incapable of that level of cooperation. Uh, they would get in a fight.

Lex Fridman 41:26 (inhales) Okay. So, um, why is this such a difficult invention of getting this bacteria inside and becoming an engine which the mitochondria is? Why was that... Why- why do you assign it such great importance? Is it great importance in terms of the difficulty of how it was to achieve or great importance in terms of the impact it had on life?

Nick Lane 41:46 Both. Uh, it had a huge impact on life because if- if that had not happened, you can be certain that life on earth would be bacterial only. It would be-

Lex Fridman 41:56 And that took a really long time to-

Nick Lane 41:58 It took two billion years.

Lex Fridman 41:59 Yeah.

Nick Lane 41:59 And it hasn't happened since to the best of our knowledge. So it looks as if it- it's genuinely difficult. And if you think about it then from- from- from just an informational perspective, you- you think bacteria have got... They- they- they structure their information differently. So a bacterial cell has a small genome. It might have 4,000 genes in it. But a single E. coli cell has access to about 30,000 genes potentially. It's got a kind of meta-genome where other E. coli out there have got different gene sets and they can switch them around between themselves. A- and so you can generate a huge amount of variation and, you- you know, they've got more g- an E. coli meta-genome is larger than the human genome. We have 20,000 genes or something. So... And they've had four billion years of evolution to work out what can I do and what can't I do with this meta-genome? And the answer is you're stuck, you're still bacteria. So they have explored...... genetic sequence space far more thoroughly than eukaryotes ever did because they've had twice as long at least and they, they've, they've got much larger populations and they never, they never got around this problem. So, why can't they? It seems as if you can't solve it with information alone so w- what's the, what's, what's the problem? The problem is structure. If s- if s- if cells, if the very first cells needed an electrical charge on their membrane to grow, and in bacteria it's the, it's the outer membrane that surrounds the cell which is electrically charged, you try and scale that up and you've got a fundamental design problem, you've got an engineering problem. And th- there are examples of it and, and what we see in all these cases is what's known as extreme polyploidy, which is to say they have tens of thousands of copies of their complete genome which is, you know, energetically hugely expensive and, uh, y- you know, it, you end up with a large bacteria with n- no further development. What you need is to in- incorporate these electrically charged power pack units inside with their control units intact, uh, and for them not to conflict so much with the host cell that, that it all goes wrong, perhaps it goes wrong more often than not, and then you change the topology of the cell. Now, you don't necessarily have any more DNA than a giant bacterium with extreme polyploidy but what you've got is, uh, an asymmetry, you now have a giant nuclear genome w- surrounded by lots of subsidiary energetic genomes that do, do all the e- d- they're the control units that are doing all the, all the, all the, all the, all the control of energy generation.

Lex Fridman 44:32 Could this have been done gradually or does it have to be done, th- the power pack has to be all intact and ready to go and-

Nick Lane 44:39 Uh...

Lex Fridman 44:39 ... working?

Nick Lane 44:40 I mean, it's a kind of step change in the possibilities of evolution but it doesn't happen overnight. It's gonna still require multiple and multiple generations so it could take, you know, it could take millions of years, it could take shorter times. This is another thing I would like to put the number of steps and try and work out what's required at each step and we, we are trying to do that with sex, for example. You can't have a very large genome unless you have sex at that point, so what are the changes to go from bacterial recombination to eukaryotic recombination, w- what, w- what do you need to do, why do we go from passing around bits of DNA as if it's loose change to fusing cells together, lining up the chromosomes, recombining across the chromosomes and then going through two rounds of cell division to produce your, your gametes? All eukaryotes do it that way. So again, you know, (laughs) w- why switch? What are the drivers here? So there's a lot of, there's a lot of time, there's a lot of evolution but as soon as you've got cells living inside another cell, what you've got is a c- is a new design, you've, you've, you've got new potential that you didn't have before.

Lex Fridman 45:39 So the cell living inside another cell, that design allows for better storage of information, better use of energy, uh, m- more delegation, like a hierarchical control of the whole thing, and then, and then somehow that leads to the ability to have multicell organisms?

Nick Lane 46:00 I'm not sure that you have hierarchical control necessarily but you, you, you've got a system where you can, you can have a, a, a much larger information storage depot in the nucleus, you can have a much larger genome and that allows multicellularity, yes, because, um, it allows you... It's a, it's a funny thing, you, to, to have a, to have a, a, a, an animal where I have, you know, 70% of my genes switched on in my brain and a different 50% switched on in my liver or something, you've got to have all those genes in the egg cell at the very beginning and you've got to have a, a, a program of development which says, "Okay, you guys switch off those genes and switch on those genes and you guys, you do that."

Lex Fridman 46:40 Mm-hmm.

Nick Lane 46:40 But all the genes are there at the beginning. That means you've got to have a lot of genes in one cell and you've got to be able to maintain them and the problem with bacteria is they don't get close to having enough genes in one cell so they w- if you were to try and make a multicellular organism from bacteria, you'd bring different types of bacteria together and hope they'll cooperate and the reality is they don't.

Lex Fridman 46:57 That's really, really tough to do.

Nick Lane 46:59 Yeah.

Lex Fridman 46:59 Combinatory.

Nick Lane 47:00 We know they don't because they're, it doesn't exist.

Lex Fridman 47:02 We have the data, as far as we know. I'm sure there's a few, like, special ones and they dead off quickly. I'd love to know some of the most fun things bacteria have done since. Like-

Nick Lane 47:12 Oh there's a f- I mean they can do some pretty funky things.

Lex Fridman 47:15 (laughs)

Nick Lane 47:15 And this is big, this is broad brushstroke that I'm talking about but it's...

Lex Fridman 47:19 Yes.

Nick Lane 47:19 Yeah.

Lex Fridman 47:19 Generally speaking.

Lex Fridman 47:20 Uh, so how was, uh, so another, you know, fun invention, us humans seem to, uh, utilize it well but you say it's also very important early on is sex. So, uh, what is sex, uh, just asking for a friend-

Nick Lane 47:35 (laughs)

Lex Fridman 47:36 ... and when was it invented and how hard is it in- to invent just as you were saying, and why was it invented? Why, how hard was it and when?

Nick Lane 47:45 I have a PhD student who's been working on this and we've just published-

Lex Fridman 47:48 On sex?

Nick Lane 47:48 ... a couple of papers on sex, yes, yes, yes.

Lex Fridman 47:50 Nice. Where do you publish these-

Nick Lane 47:52 (laughs)

Lex Fridman 47:52 ... this biology, is it biology, genetics journals?

Nick Lane 47:54 Yeah, well this, this is actually P- PNAS which is the, um, Proceedings of the National Academy.

Lex Fridman 48:00 So like broad, big, big picture stuff.

Nick Lane 48:02 Everyone's interested in sex.

Lex Fridman 48:03 Yeah (laughs) .

Nick Lane 48:04 The, the, the job of biologists is to make sex dull.

Lex Fridman 48:07 (laughs) Yes, yeah, that's, that's a beautiful way to put it okay so when was it invented?

Nick Lane 48:13 Uh, it was invented with eukaryotes about two billion years ago. Um, all eukaryotes share the same basic mechanism that you produce gametes, that gametes fuse together so a gamete is, is the, the egg cell and the sperm. They're not necessarily even different in size or shape, uh, so the, the simplest eukaryotes produce what are called motile gametes, they're all like sperm and they all swim around and they find each other and they fuse together, they don't have kind of much, much going on there beyond that. And then these are haploid which is to say we all have two copies of our genome and the, the gametes have only a single copy of the genome so when they fuse together you now become diploid again which is to say you now have two copies of your genome and what you do is you line them all up...Um, and then you, and then you double everything. So now we have four copies of the complete genome and then we criss-cross between all of these things. So we take a bit from here and stick it on there, and a bit from here and we stick it on there. That's recombination. Um, and, and then we go through two rounds of cell division. So we divide in half, so now the two daughter cells have two copies. Then we di- divide in half again. Now we have some gametes, each of which has got a single copy of the genome. And that's the basic ground plan for what's called meiosis and, uh, and syn-gamy, that's, that's basically sex. Uh, and it happens at the level of single-celled organisms and it happens pretty much the same way in plants, and pretty much the same way in animals and so on. And it's not found in any bacteria. They switch things around using the same machinery and they take up a bit of DNA from the environment. They take out this bit and stick in that bit, and it's the same molecular machinery they're using to do it.

Lex Fridman 49:50 So what about the kind of, you said find each other, this kind of imperative-

Nick Lane 49:54 Yeah.

Lex Fridman 49:54 ... to find each other? What is that? Like, is that-

Nick Lane 49:58 Well, you've got a few cells together. So the bottom, the bottom line on all of this is, is, is bacteria... Or, I mean, it's kind of simple, uh, when, when, when you've figured it out. And figuring it out, this is not me, this is my PhD student, Marco Colnaghi. Um, and, uh, and, and in effect, if you, if you're doing lateral... Y- you're an E. coli cell. You've got 4,000 genes. You want to scale up to a eukaryotic size. Uh, I wanna have 20,000 genes. Um, and I'm, uh, and I need to maintain my genome so it doesn't get shot to pieces by mutations. And I'm gonna do it by lateral gene transfer. So I know I've got a mutation in a gene, I don't know which gene it is 'cause I'm not sentient, but I know I can't grow, I know my regulation systems are saying, "There's something wrong here, there's something wrong. Pick up some DNA. Pick up a bit of DNA from the environment." If you've got a small genome, the chances of you picking up the right bit of DNA from the environment is much higher than if you've got a genome of 20,000 genes. To do that, you've, you've effectively gotta be picking up DNA all the time, all day long and nothing else and you're still gonna get the wrong DNA. You've gotta pick up large chunks, and in the end you've gotta line them up. You're forced into sex (laughs) , to coin a phrase. Um, so you're-

Lex Fridman 51:11 (laughs) You're for-

Nick Lane 51:11 (laughs)

Lex Fridman 51:12 Uh, so it's, it's... So there is a kind of, uh, uh, incentive, uh, to

Narrator 51:18 ... to talk about.

Nick Lane 51:18 If you wanna have a large genome, you've got to prevent it mutating to nothing. That will happen with bacteria, so it's another reason why bacteria can't have a large genome. But as soon as you give them the power pack, as soon as you give eukaryotic cells the power pack that allows them to increase the size of their genome, then you face the pressure that you've got to maintain its quality. You've got to stop it just mutating away.

Lex Fridman 51:38 What about sexual selection? So the, the finding, uh, like, "Uh, I don't like this one, I don't like this one. This one seems all right." Like, what's the, the, the, the... Is, is it... At which point-

Nick Lane 51:51 Yeah.

Lex Fridman 51:51 ... does it become less random?

Nick Lane 51:52 It's hard to know, uh-

Lex Fridman 51:54 'Cause eu- eukaryotes just kind of float around.

Nick Lane 51:55 I mean-

Lex Fridman 51:56 They just kind of have-

Nick Lane 51:57 Yeah.

Lex Fridman 51:57 Th- their like-

Nick Lane 51:57 I mean, is there sexual selection-

Lex Fridman 51:59 It's kind of like tinder these days.

Nick Lane 51:59 ... in single-celled eukaryotes? There probably is, it's just that I don't know very much about it. By the time we get on to-

Lex Fridman 52:03 You don't hang out with euk- (laughs) eukaryotes?

Nick Lane 52:05 I... Well, I do all the time but I, you know... (laughs)

Lex Fridman 52:07 But don't, you can't communicate with them yet.

Nick Lane 52:08 Yeah. A peacock or something-

Lex Fridman 52:11 Yes.

Nick Lane 52:11 ... um, the kind of standard an- this is not quite what I work on, but the standard answer, uh, is that sh- it's female mate choice. She is looking for good genes. Um, and, and if you can have a tail that's like this, uh, and, and s- and still survive, still be alive, not actually have been taken down by the nearest predator, then you must've got pretty good genes 'cause (laughs) despite this handicap, uh, you're able to survive. So-

Lex Fridman 52:36 So those are like human interpretable things, like with a peacock. But I wonder, I'm sure echoes of the same thing are there with more primitive organisms. Basically, your PR-

Nick Lane 52:48 Yes.

Lex Fridman 52:48 ... like, uh, how you advertise yourselves that you're worthy of, uh-

Nick Lane 52:54 Yeah. Absolutely.

Lex Fridman 52:54 ... so one big advertisement is the fact that you survived at all. (laughs) That's, that's pretty-

Nick Lane 52:58 Let me give you one, one beautiful example-

Lex Fridman 53:00 Yes.

Nick Lane 53:00 ... uh, of a, of an algal bloom. And this can be, this can be a, a sign of bacter- this can be in bacteria, uh, i- uh, so, so if, if suddenly you, you, you know, you pump nitrate or phosphate or something into the ocean and, and you, everything goes green, you end up with all this, uh, a- a- algae growing there. Um, a viral infection or something like that can kill the entire bloom overnight. And it's not that the virus takes out everything overnight, it's that most of the cells in that bloom kill themselves before the virus can get onto them. And it's through a form of cell death called programmed cell death, and we, we do the same things. It's how we have the different, uh, you know, the gaps between our fingers and so on, it's how we craft synapses in the brain, um, it, it, you know, it's fundamental, again, to, to, um, to multicellular life. They have the same machinery in these, in these algal blooms. How do they know who dies? The answer is they will often put out a toxin and that toxin is a kind of a challenge to you. Either you can cope with the toxin or you can't. If you can cope with it, you form a spore and you will go on to become the next generation. You, you're, you'll, you'll form a kind of a resistance spore. You sink down a little bit, you get out of the way, you're outta the, out, out of... You can't be attacked by a virus if you're a spore, or at least not so easily. Whereas if you can't deal with that toxin, you pull the plug and you, you, you, you, you trigger your death apparatus and you kill yourself.

Lex Fridman 54:27 Oh, so it's truly life and death situation.

Nick Lane 54:29 Yeah. So it's really, it's a challenge. And this is a bit like sexual selection. It's, it's not something... They're all pretty much genetically identical but they've had different life histories. So have you had a, (laughs) you know, tough day? Did you, did you happen to get infected by this virus or did you run out of iron or did you get a bit too much sun? Whatever it may be. If this extra stress of the toxin just pushes you over the edge, then you have this binary choice. Either you're the next generation or you kill yourself now using this same machinery.

Lex Fridman 54:58 It's also actually exactly the way I approach dating but that, that-

Nick Lane 55:01 (laughs)

Lex Fridman 55:01 ... is probably why I'm single.

Lex Fridman 55:03 Okay, uh, what about, if we can step back, DNA?... just mechanism of storing information. RNA, DNA-

Nick Lane 55:11 Yeah.

Lex Fridman 55:11 ... how big of an invention was that? That seems to be you- that seems to be fundamental to like something deep within what life is, is the ability, as you said, to kind of store and propagate information. But then you also kind of inferred that w- with your and your students' work, that there's a deep connection between the chemistry and the ability, uh, to have this kind of genetic information. So, how big of an invention is, is it to have a nice representation, nice hard drive for info to pass on?

Nick Lane 55:46 Huge, I suspect. Uh, I mean, but when I was talking about the code, you see the code in RNA as well. Uh, and RNA almost certainly came first. Um, and, and there's been a- an idea going back decades called the RNA world, because RNA, in theory, can copy itself and can catalyze reactions. So, it kind of cuts out this chicken and egg loop.

Lex Fridman 56:07 So, DNA, it's possible, is not that special.

Nick Lane 56:10 So, R- RNA, RNA is the thing that does the work, really, and, and the code lies in RNA. The code lies in the interactions between RNA and amino acids. And it still is there today in the ribosome, for example, which is just kind of a giant ribozyme, which is to say it's an enzyme that's made of, uh, of RNA. Um, so getting to RNA, I suspect, is probably not that hard but getting from RNA... How do you... Uh, you know, there's multiple different types of RNA now. How do, how do, how do you distinguish? This is something we're actively thinking about. How do you distinguish between, you know, a random population of RNAs? Some of them go on to become messenger RNA. That, this is the, the, the transcript of the code of the gene that you, you want to make. Some of them become, uh, transfer RNA, which is, which is the kind of the unit that holds the amino acid that's gonna be poly- pro- polymerized. Some of them become, uh, ribosomal RNA, which is the machine which is joining them all up together. How do they discriminate themselves and, and, and... You know, there's some kind of phase transition going on there, what's that? I don't know. It's a difficult question. And we're now in the region of biology where information is coming in. But the thing about RNA, it's very, very good at what it does, but the largest genomes supported by RNA are RNA viruses, like HIV, for example. They're pretty small. Um, and, and so there's a limit to how complex life could be, unless you come up with DNA, which chemically is a really small change, but how easy it is to make that change, I don't really know. As soon as you've got DNA, then you've got a- an amazingly stable molecule for information storage, um, and you can do absolutely anything. But how likely that transition from RNA to DNA was, I don't know either.

Lex Fridman 57:54 How much possibility is there for variety in, uh, ways to store information? 'Cause it seems to be very... There's specific characteristics about the, the programming language of DNA.

Nick Lane 58:06 Yeah. There's a lot of work going on in what's called Xeno-DNA, or, I don't know, or RNA. Can we replace the, the bases themselves, the, the letters, if you like, in, in, in, in RNA or DNA? Can we replace the backbone? Can we replace, for example, phosphate with arsenate? Uh, can we replace the sugar ribose or deoxyribose with a different sugar? And the answer is, yes, you can. Um, within limits. Th- there's not an infinite space there. Uh, uh, arsenate doesn't really work if the bonds are not as strong as phosphate. It's probably quite hard to replace phosphate. Um, it's possible to do it. The question to me is, why is it this way?

Lex Fridman 58:47 Right.

Nick Lane 58:47 Is it because there was some form of selection that this is better than the other forms, and there were lots of competing forms of information storage early on, and this one was the one that worked out? Or was it kind of channeled that way, that these are the molecules that you're dealing with, um, and, and, and they work? Uh, and I'm increasingly thinking it's that way, that we're channeled towards ribose, phosphate and, and, and, and the bases that are used. But there are, you know, 200 different letters kicking around out there that could have been used.

Lex Fridman 59:17 It's such an interesting question. If you look at, in the programming world, in, in computer science, there's a programming language called JavaScript-

Nick Lane 59:24 Yeah.

Lex Fridman 59:24 ... which was, uh, written super quickly, it's a giant mess-

Nick Lane 59:27 (laughs)

Lex Fridman 59:27 ... but it took over the world. And it was kind of a-

Nick Lane 59:30 Sounds very biological. (laughs)

Lex Fridman 59:31 It, it wa- it was kind of a running joke that like, um, like surely this can't be the th- it's a terrible programming language, it's a giant mess, it's full of bugs, it's so easy to write really crappy code, but it took over all of front-end development in the web browser. If you have any kind of dynamic interactive website, it has, it's usually running JavaScript, and it's now taking over much of the backend, which is like the serious, heavy-duty computational stuff, and it's become super fast with the different compilation engines, um, that are running. And so it's like, it really took over the world. It's very possible that this initially crappy, uh, derided language actually takes everything over. And then the question is, did human civilization always strive towards JavaScript?

Nick Lane 1:00:22 (laughs)

Lex Fridman 1:00:22 Or was JavaScript just the first programming language that ran in the browser and still sticky? The first, the first is the sticky one, and so it wins over anything else because it was first. And that we... I don't think that's answerable, right? But it's good to-

Nick Lane 1:00:36 Yeah.

Lex Fridman 1:00:36 ... ask that. I suppose in a lab, uh, you ca- (laughs) you can't, um, run it with programming languages, but in biology you can probably do some kind of, um, small scale evolutionary test to try to infer which, which is which?

Nick Lane 1:00:54 Yeah. I mean, in, in a way we've g- we've got the hardware and the software here, and, and the, the hardware is maybe the, the DNA and the RNA itself. And then the software per- perhaps is more about the code, uh, is... Did the code have to be this way? Could it have been a different way?

Lex Fridman 1:01:08 Yeah.

Nick Lane 1:01:09 Um, people talk about the optimization of the code, and there's some suggestion for that. Uh, I think it's weak, actually.... but you could imagine, you could come up with a million different codes and, and this would be one of the best ones.

Lex Fridman 1:01:21 Yeah.

Nick Lane 1:01:21 Um... This-

Lex Fridman 1:01:22 Well, we don't know this.

Nick Lane 1:01:24 Well, peop-

Lex Fridman 1:01:25 We don't know this.

Nick Lane 1:01:25 I mean, people have tried to model it based on the effect that mutations would have.

Lex Fridman 1:01:30 Ah.

Nick Lane 1:01:30 Um, so, no, you're right, we don't know because that's a sin- that's a single assumption that a mutation is, is wha- what's being selected on there, and there's other possibilities too.

Lex Fridman 1:01:39 I mean, there does seem to be a resilience and a redundancy to the whole thing.

Nick Lane 1:01:43 Yeah.

Lex Fridman 1:01:43 It's hard to mess up. And, and the way you mess it up often is likely to produce interesting results. So it's, um...

Nick Lane 1:01:52 Are you talking about JavaScript or the genetic code now?

Lex Fridman 1:01:54 Both. (laughs)

Nick Lane 1:01:55 Yeah. Well, I- I mean-

Lex Fridman 1:01:56 (laughs)

Nick Lane 1:01:56 ... it's almost, uh, you know, biology is underpinned by this kind of mess as well.

Lex Fridman 1:02:00 Yeah.

Nick Lane 1:02:00 When you look at the human genome and it's full of stuff that is really either broken or dysfunctional or was a virus once, whatever it may be, and somehow it works. And maybe we need a lot of this mess. You know, we know that some functional genes are taken from this mess.

Lex Fridman 1:02:15 So what about, you mentioned predatory behavior.

Nick Lane 1:02:19 Yeah.

Lex Fridman 1:02:20 We talked about sex. What about violence?

Nick Lane 1:02:22 (laughs)

Lex Fridman 1:02:22 Predator and prey dynamics. How, uh... When was that invented? And, uh, poetic and biological ways of putting it, like what, how do you describe a predator-prey relationship? Is it a beautiful dance or is it a-

Nick Lane 1:02:39 Hmm.

Lex Fridman 1:02:40 ... violent atrocity?

Nick Lane 1:02:42 Well, I guess it's both, isn't it? I mean, when does it start? It starts in bacteria. You see these amazing predators, Bdellovibrio is one that, uh, Lynn Margulis used to talk about a lot. Um, it's, it's got a kind of a drill piece that, uh, drills through the wall and the membrane of the bacterium, and then i- it effectively eats the bacterium from just inside the periplasmic space and makes copies of itself that way. So that's straight predation. There are predators among bacteria.

Lex Fridman 1:03:08 So predation in that... Sorry to interrupt, means you murder somebody and use their body as a resource-

Nick Lane 1:03:15 Yes.

Lex Fridman 1:03:16 ... in some way?

Nick Lane 1:03:17 Yeah.

Lex Fridman 1:03:18 But it's not parasitic in that you need them to be still alive in some way?

Nick Lane 1:03:24 No, no, I mean, predation is you kill them, really.

Lex Fridman 1:03:26 You murder, yeah.

Nick Lane 1:03:27 Parasite is, uh, you kind of live on them. (laughs)

Lex Fridman 1:03:30 Okay.

Nick Lane 1:03:30 Yeah.

Lex Fridman 1:03:31 So, but it seems the predator is the really popular, uh, um, too.

Nick Lane 1:03:35 So what we see if we go back 560, 570 million years before the Cambrian explosion, there is, um, what's known as the Ediacaran fauna, or sometimes they're called vendobionts, which is a lovely name. Uh, and, and, and it, it's not obvious that they're animals at all. Uh, they're stalked things. They often have fronds that look a lot like leaves with kind of fractal branching patterns on them. Um, and the thing is they've, they're found sometimes, you know, geologists can figure out the environment that they were in and say, "This was more than 200 meters deep because there's no sign of any waves, there's no, you know, there's n- no storm damage down here," this kind of thing. They were more than 200 meters deep so they're definitely not photosynthetic. These are animals. Um, and they're, they're filter feeders, and we know thin- you know, sponges and corals and things are filter feeding animals, they're stuck to the spot. Uh, and, and little bits of carbon that come their way, they, they filter it out and that's what they're eating. Um, so no predation involved in this beyond stuff just dies anyway, and it feels like a very gentle, rather beautiful, rather limited world, you might say. Uh, there's not a lot going on there. And something changes. Oxygen definitely changes during this period, other things may have changed as well, but the next thing you really see in the fossil record is the Cambrian explosion. And what do we see there? We're now seeing animals that we would recognize. They've got eyes, they've got claws, they've got shells, they're, you know, they're plainly killing things or running away, um, and, and, and hiding. Um, and, and so we've gone from a, a rather gentle but limited world to a rather vicious, unpleasant, um, world that we recognize, um, and which leads to, uh, kind of arms races, evolutionary arms races. Um, which again is something that when we think about a nuclear arms race, we think, "Jesus, we don't wanna go there. It's not done anybody any good." In some ways, maybe we... (sighs) maybe it does do good. I, I, I don't wanna make an argument for nuclear arms but, but predation, as a, as a mechanism, forces organisms to adapt, to change, to be better to escape to, to... or, or to kill. Um, if you need to eat, then you, you've got to eat, and, you know, a cheetah's not gonna run at that speed unless it's, uh, un- un- unless it has to because the, the zebra is capable of escaping. So it leads to, to much greater feats of evolution, whatever have been possible without it, and in the end, to a much more beautiful world. Mm-hmm.

Lex Fridman 1:06:13 Uh, and so it's not all bad (laughs) by any means. The, the... But the thing is, you can't have this if you don't have an oxygenated planet because if you... it, it's all, in the end, it's about how much energy can you extract from the food you eat. And if you don't have an oxygenated planet, you can get about 10% out, not much more than that. Um, and if you've got an oxygenated planet, you can get about 40% out. And that means you can have, instead of having one or two trophic levels, you can have five or six trophic levels, and that means things can eat things that eat other things and so on, and, and, and you've gone to a, a level of ecological complexity which is completely impossible in the absence of oxygen. This reminds me of the Hunter S. Thompson quote, that "For every moment of triumph, for every instance of beauty, many souls must be trampled."

Nick Lane 1:07:00 (laughs) Yes.

Lex Fridman 1:07:01 I... The, the history of life on Earth, unfortunately, is, uh, that of violence. Just the trillions and trillions of multicell organisms that were murdered in the, in the s- struggled for survival.

Nick Lane 1:07:17 It's a sorry statement, but yes, it's basically true. Uh-

Lex Fridman 1:07:20 And that somehow is a catalyst...... from an evolutionary perspective, for creativity, for creating more and more complex organisms that are better and better at surviving.

Nick Lane 1:07:30 I mean survival of the fittest-

Lex Fridman 1:07:32 Yeah.

Nick Lane 1:07:32 ... if you just go back to that old phrase, means death of the weakest. Um, now what's fit, what's weak? They are- these are terms that, that don't have much intrinsic meaning, but the thing is evolution only happens because of death.

Lex Fridman 1:07:45 One way to die is the, the constraints, the scarcity of the resources in the environment, but that seems to be not nearly as good of a mechanisms, mechanism for death than other creatures roaming about in the environment. When I say environment, I mean like the static environment, but then there's the dynamic environment of bigger things trying to eat you and use you for your energy. (takes deep breath)

Nick Lane 1:08:10 It forces you to come up with a, with a solution to your specific problem-

Lex Fridman 1:08:15 (laughs)

Nick Lane 1:08:15 ... that you, that, that is inventive and is new and hasn't been done before. And so it, it forces, I mean literally, uh, change, literally evolution, uh, on- on- on- on populations. They have to become different.

Lex Fridman 1:08:27 And it's interesting that humans have channeled that into more... I mean, I guess what humans are doing is they're inventing more productive and safe ways of doing that. You know, this whole idea of morality and all those kinds of things, I think they ultimately lead to competition versus violence 'cause I think violence can have a cold, brutal, inefficient aspect to it. But if you channel that into more, uh, controlled competition in the space of ideas, um, in the space of approaches to life, maybe you can, um, (clicks tongue) be even more productive than evolution is, 'cause evolution is very wa- wasteful. Like the amount of murder required to really test a good idea-

Nick Lane 1:09:16 Yeah.

Lex Fridman 1:09:16 ... genetically speaking-

Nick Lane 1:09:17 Yeah, yeah, yeah.

Lex Fridman 1:09:17 ... is just a lot.

Nick Lane 1:09:18 Yeah. I mean-

Lex Fridman 1:09:19 Many, many, many generations.

Nick Lane 1:09:21 Morally we cannot (sighs) base society (laughs) on the way that evolution works.

Lex Fridman 1:09:26 That's, that's an invention, right? Morality.

Nick Lane 1:09:27 Um, but actually we, in, in some respects, we do, which is to say this is how science works. We have competing hypotheses that have to get better, otherwise they die. It's the way that society works. We, you know, in the, in- in- in ancient Greece, we had, we had the- the- the- the- Athens and Sparta and city-states, and then we had the Renaissance and- and- and nation-states. And we com- you know, universities compete with each other.

Lex Fridman 1:09:48 Yes.

Nick Lane 1:09:48 Tremendous amount. There's companies competing with each other all the time. It, it drives innovation. Um, and if we want to do it without all the death that we see in nature, then we have to have some kind of societal level control that says, "Well, hit the s- there's some limits, guys. And these are what the limits are gonna be." And society as a whole has to say, "Right, we- we want to limit the amount of death here, so you can't do this and you can't do that." And, you know, who makes up these rules and how do we know? It's- it's a tough thing, but it's basically trying to find a moral basis for avoiding the death of evolution and natural selection, and keeping the- the- the innovation and the- and- and the richness of it.

Lex Fridman 1:10:27 And I forgot who said it, but, um, that murder is illegal... probably Kurt Vonnegut.

Nick Lane 1:10:33 (laughs)

Lex Fridman 1:10:33 Murder is illegal except when it's done to the sound of trumpets and at a large scale. So we still have wars.

Nick Lane 1:10:40 Mm-hmm.

Lex Fridman 1:10:41 Um, but we are struggling with this idea that murder is a bad thing. It's so interesting how we're channeling the best of the evolutionary imperative and trying to, um, get rid of the stuff that's not productive, as if trying-

Nick Lane 1:10:58 But, uh-

Lex Fridman 1:10:59 ... to almost accelerate evolution. The same kind of thing that, um, uh, makes evolution creative, we're trying to use that.

Nick Lane 1:11:07 I think we naturally do it. I mean, I don't think we can help ourselves, do it. And I, you know, capitalism-

Lex Fridman 1:11:12 (laughs) That's hard to know.

Nick Lane 1:11:12 Capitalism as a form is- is basically about competition and- and- and differential rewards. But we... society and, you know, we have a, (sighs) I- I- I keep using this word, moral obligation, but it, you know, it- we- we cannot operate as a society if we go that way. It's interesting that (sighs) we've had problems achieving balance. So for example, in the f- in the financial crash in 2009, do you let banks go to the wall or not? This kind of question. In evolution, certainly you let them go to the wall, and- and- and in that sense, you don't need the regulation because they just die. Um, s- whereas if we, as a society, think about what's required for society as a whole, then you don't necessarily let them go to the wall. Uh, in which case you then have to impose some kind of regulation that the bankers themselves will, in an evolutionary manner, exploit.

Lex Fridman 1:12:08 Yeah. That's... We've been struggling with this kind of idea of capitalism, the- the- the cold brutality of capitalism that seems to create so much beautiful things in this world, and then the- the ideals of communism that seem to create so much brutal destruction in history.

Nick Lane 1:12:26 Mm.

Lex Fridman 1:12:26 And we struggle with ideas of, "Well, maybe we didn't do it right. How can we do things better?" And then the ideas are the things we're- we're playing with, as opposed to people. If a PhD student has a bad idea, we don't shoot the PhD student.

Nick Lane 1:12:39 (laughs)

Lex Fridman 1:12:39 We- we just criticize their idea and hope they improve it.

Nick Lane 1:12:42 You have a very humane lab. (laughs)

Lex Fridman 1:12:44 (laughs) Yeah. I don't know how you guys do it, you know. The way I run things, uh, it's always life and death. Okay.

Lex Fridman 1:12:50 So it is interesting about humans that there is an inner sense of morality, which begs the question of, how did homo sapiens evolve? If we think about the invention of, uh, early invention of sex and early invention of predation, what was the thing invented to make humans? What- what would you say?

Nick Lane 1:13:17 I mean, I- I suppose a couple of things I'd say. N- number one is y- you don't have to wind the clock back very far, five, six million years or so, and- and- and- and- and let it run forwards again, and the chances of humans as we know them is not necessarily that high.You, you know, imagine as an alien you find planet Earth and it's got everything apart from humans on it. It's an amazing, wonderful, marvelous planet, but nothing that we would recognize as extremely intelligent life, you know, space-faring civilization. So when we think about aliens, we, we, we're kind of after something like ourselves. We're after a space-faring civilization. We're not after, you know, z- zebras and giraffes and lions and things, amazing though they are. But the, the additional kind of evolutionary steps to go from large, complex mammals, monkeys let's say, to, to humans doesn't strike me as that long a, a distance. It's all about the brain. And where's the br- where's the brain and morality coming from? It seems to me to be all about groups, human groups and interactions between groups.

Lex Fridman 1:14:22 The collective intelligence of it. The-

Nick Lane 1:14:24 Yes.

Lex Fridman 1:14:24 Yeah, the, the-

Nick Lane 1:14:25 The interactions really. And there's, there's some, there's a guy at UCL, uh, called Mark Thomas who's done a lot of really beautiful work, I think, on, on those kind of questions, so I talk to him every now and then, so my views are influenced by him. Um, but a lot seems to depend on population density, that the more interactions you have going on between different groups, the more transfer of information, if you like, between groups, so people moving from one group to another group, almost like lateral gene transfer in bacteria, um, the more expertise you're able to develop and maintain, the more culturally complex your society can become. And, and, and groups that have become detached, um, like on Easter Island for example, very often degenerate in terms of the complexity of their civilization.

Lex Fridman 1:15:13 Is that true for complex organisms in general, population density-

Nick Lane 1:15:17 Really matters.

Lex Fridman 1:15:17 ... is often productive?

Nick Lane 1:15:19 Really matters. But in human terms, um, I don't know what the actual factors were that were driving a, a, a large brain, but you know, you can, you can talk about fire, you can talk about tool use, you can talk about language, and none of them seem to correlate especially well with the actual known trajectory of human evolution in terms of cave art and these kind of things. That, that seems to work much better just with, with population density and number of interactions between different groups. All of which is really about human interactions, human-human interactions and the complexity of those.

Lex Fridman 1:15:58 But population density is the thing that increases the number of interactions, but then there must have been inventions, uh, forced by that number of interactions that actually led to humans. So like Richard Wrangham-

Nick Lane 1:16:16 Yeah.

Lex Fridman 1:16:16 ... talks about that it's basically the beta males had to beat up the alpha male. So that's what collaboration looks like, is they-

Nick Lane 1:16:24 (laughs)

Lex Fridman 1:16:24 When you're living together, they don't like to s- The, the, our early ancestors don't like the dictatorial aspect of a single individual at the top of a tribe. So they, uh, they, they learn to collaborate how to, uh, basically (laughs) create a democracy, uh, of sorts.

Nick Lane 1:16:42 Yeah.

Lex Fridman 1:16:42 A democracy that prevents, minimizes, or lessens the amount of violence, which essentially gives strength to the tribe and make the war between tribes, uh, versus the dictator less-

Nick Lane 1:16:55 I mean, I think one of the most wonderful things about humans is we're all of those things. I mean, we are deeply social as a species, and we're also deeply selfish. And it seems to me the conflict between capitalism and, and communism, it's really just two aspects of human nature, both of which are-

Lex Fridman 1:17:11 We have both.

Nick Lane 1:17:11 We have both. Uh, and, and we have a constant kind of vying between the two sides. We, we really do care about other people beyond our families, beyond our immediate people. We care about society and the society that we live in. And, and you could say that's a, you know, a drawing towards socialism or communism. On the other side, we really do care about ourselves. We really do care about our families, about working for something that we gain from. And that's the capitalist side of it. They're both really deeply ingrained in human nature. In terms of violence, um, and, and, and interactions between groups, yes, all this dynamic of if you're interacting between groups, you can be certain that, that, that they're gonna be burning each other, and, and all kinds of interac- physical, violent interactions as well, which will drive the kind of cleverness of how do you resist this? Let's build a tower. Let's, you know, what, what are we gonna do to, to, to prevent being overrun by those marauding gangs from over there? Um, a- and you look, you look outside humans and you look at chimps and bonobos and so on, and, and they're very, very different structures to society. Chimps tend to have an aggressive alpha male type structure, and bonobos are, you know, they, they, they are... There's basically a female society where the males are predominantly excluded and only brought in at the behest of the female. We sh- have a lot in common with both (laughs) -

Lex Fridman 1:18:28 Yeah.

Nick Lane 1:18:28 ... both of