Nick Lane: Origin of Life, Evolution, Aliens, Biology, and Consciousness | Lex Fridman Podcast #318
- 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. 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. Why doesn't that happen is
because of the kinetic barriers, that's where you need the spark. - The following is a
conversation with Nick Lane, a biochemist at University College London, an 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 the "Lex Friedman Podcast." To support it, please check out our
sponsors in the description. And now, dear friends, here's Nick Lane. Let's start with perhaps
the most mysterious, the most interesting question that we little humans
can ask of ourselves: How did life originate on Earth? - You could ask anybody
working on the subject, and you'll get a different
answer from all of them. They will be pretty
passionately held opinions, and their opinion's grounded in science, but they're still really, at this point, their opinions, 'cause there's so much stuff to know that all we can ever do is get
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? Why is it this way? Why is it made of cells? Why is it made of carbon? 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, which generate hydrogen
gas in bucket loads and electrical charges on
kind of cell-like pores that can drive the kind of
chemistry that life does. So, it seems so beautiful and so obvious 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 gonna be. But it looks, I would say, more true rather than less true over that 10-year period, I think. I have to take a step back
every now and then and think, hang on a minute, where's this going? I'm happy it's going in
a sensible direction. 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'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. So I think they're fundamental reasons, and I think we need to worry about them. - Yeah, there might be some deep truth to the puzzle here on Earth that will resonate with
other puzzles elsewhere, that 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. - 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.
- Yeah. - But it matters most to the
origin of life to be not there. As I see it, we have this, I mean, life is made of
carbon basically, primarily. Organic molecules with
carbon-carbon bonds. And the building block, the Lego brick that we take outta the air or take outta the oceans
is carbon dioxide. And to turn carbon dioxide
into organic molecules, we need to strap on hydrogen. And so we need, and then, and this is basically what life is doing, it's hydrogenating carbon dioxide, it's taking the hydrogen
that bubbles outta the Earth in these hydrothermal vents, and it sticks it on CO2. And it's kind of really as simple as that. And actually, thermodynamically, the thing that I find
most troubling is that 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. - Is there something to be
said about the earliest origins of that little potion, that chemical process? What really is the spark there? - There isn't a spark. 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. - So literally spark. (chuckles) - Well, the charge, at least, but yes, I mean, a spark in that sense is, we tend to think of in
terms of Frankenstein, we tend to think in terms of electricity, one moment you zap something, and it comes alive. And what does that really mean? It's come alive, and now
what's sustaining it? Well, (chuckles) we are
sustained by oxygen, by this continuous chemical reaction. And if you put a plastic bag on your head, then you got a minute or
something before it's all over. - So some way of being able to
leverage a source of energy. - 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. 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. So, why doesn't that happen is because of the kinetic barriers, that's where you need the spark. - Is it possible that life
originated multiple times on Earth? The way you describe it, you make it sound so easy, - (chuckles) There's a long distance to go from those first bits
of prebiotic chemistry to, say, molecular
machines like ribosomes. - Is that the first thing
that you would say is life? Like, if I introduce the
two of you at a party, you would say that's a living thing? - I would say as soon as we
introduce genes, information, into systems that are growing anyway, so I would talk about growing protocells, as soon as we introduce even random bits of information into there, I'm thinking about RNA
molecules, for example, doesn't have to have
any information in it, 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 allow it to do so better or worse are now selected by perfectly
normal natural selection. - [Lex] But it's a system. - So, that's when it
becomes alive to my mind. - That's encompassed into, like, an object that keeps information and evolves that information over time or changes that information over time. - Yes, exactly.
- In response to the environment.
- So it's always part of a cell system from the very beginning. - So is your sense that
it started only once because it's difficult, or is it possible it started
in multiple occasions on Earth? - It's possible it started
multiple occasions. There's two provisos to that, one of them is, oxygen makes it impossible,
really, for life to start. So as soon as we got
oxygen in the atmosphere, then life isn't gonna keep starting over. So, I often get asked by people, you know, 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, if you want hydrogen to react with CO2 and there's oxygen there, hydrogen reacts with oxygen instead, it's just, you know, you get an explosive reaction that way, it's rocket fuel. So it's never gonna happen. But the other, 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, but there's a fairly
interesting deep split in life between bacteria and
what are called archaea, which look just the same as bacteria. And they're not quite
as diverse but nearly, and they are very different
in their biochemistry. And so any explanation for the origin of life
has to 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. - Can you describe the difference
that's interesting there? How they're similar,
how they're different? - Well, they're different in
their membranes primarily. They're different in things
like DNA replication, they use completely different enzymes and the genes behind
it for replicating DNA. - So they both have membranes, both have DNA replication. - Yes.
- The process of that is different. - They both have DNA, the genetic code is
identical in them both, the way in which it's transcribed into RNA into the copy 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 processes could drive that divergence very early on? I can think about it
in terms of membranes, in terms of the electrical
charges on membranes. And it's that that makes me think that there were probably
many unsuccessful attempts and only one really successful attempt. - Can you explain why that
divergence makes you think there's one common ancestor? Like, can you describe that intuition? I'm a little bit unclear about why, like, the leap from the
divergence means there's one. Do you mean, like, the
divergence indicates that there was a big
invention at that time? - Yes.
- From one source. - If you'd got, as I imagine it, you have 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 kinda take over the world and wipe out everything else, and so what you would see would
be a single common ancestor for all of life but with, you know, lots
of different vent systems all kind of vying to create
the first life forms, you might say. - [Lex] So this thing is a cell. A single cell organism.
- Well, we're always talking about populations of cells, but yes, these are
single celled organisms. - But the fundamental life
form is a single cell, right? So, like, (chuckles) so they're always together, but they're alone together. (laughs) - Yeah.
- There's a machinery in each one individual component-
- Yes. - That if left by itself
would still work, right? - 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 unless
you have a population, you can't evolve, you can't change. - Right, but there was one Chuck Norris, it's an American reference. - [Nick] Yeah. - A cell that made it
out of the vents, right? Or, like, the first one. - So imagine then that
there's one cell gets out and it takes over the world. - It gets out in the water, it's, like, floating around. - We're deep in the ocean somewhere. - Yeah.
- But actually, two cells got out, and they appear to have
got out from the same vent 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 all these different vents, so either they all have the same code and two cells spontaneously
emerged from different places or two different cells, fundamentally different cells, came from the same place. So, either way, what are the constraints that say, not just one came out or not half a million came out, but two (chuckles) came out, that's kind of a bit strange. 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 do that yourself, you've gotta power up your own membrane. And so the question is, well, how do you power up your own membrane? 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 both emerged
from a common ancestor. As soon as you've got that ancestor, things move very quickly 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 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. - It all started from one organism, and then that organism just start replicating
the heck out of itself with some mutation of the DNA. So, like, there's some, there's a competition through
the process of evolution. They're not, like, trying
to beat each other up. They're just trying to live life. - They're just replicators. - Yeah, well, you know, let's not minimize their-
- Yeah. - They're just trying to chill, they're trying to relax, but there's no sense of trying to survive, they're replicating. - I mean, there's no sense in which they're trying to do anything. They're just kind of an
outgrowth of the Earth, you might say. - Of course, the aliens
would describe us humans in that same way. (chuckles) - They might be right.
- This primitive life. It's just ants that are hairless, mostly hairless.
- Overgrown ants. - Overgrown ants. Okay, what do you think
about the idea of panspermia, the theory that life did
not originate on Earth and was planted here from outer space? Or pseudo-panspermia, which is, like, the basic ingredients, the magic that you mentioned, was planted here from elsewhere in space? - I don't find them helpful. That's not to say they're wrong. So, pseudo-transpermia, 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 that they're
delivered on meteorites, comets, and so on. So what do they do next? That's, to me, the question. Well, what they do is they stock a soup. Presumably, they land
in a pond or in an ocean or wherever they land. And then you end up with, you know, 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, gloop, (chuckles) become alive. So how did they do that? You may as well say
that a miracle happened. I don't believe in soup. 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 more of yourself, you might say, even if it's a small bit. So you've got a kind of
continuous self-organization and growth from the very beginning. You never have that in a soup. - Isn't the entire universe and living organisms in the universe, isn't it just soup all the way down? Isn't it all soup?
- No, no. I mean, soup almost by definition
doesn't have a structure. - But soup is a collection of ingredients that are, like, randomly interacting. - Yeah, but they're not random. They're not, I mean, we have chemistry going on here, we have membranes forming, which are, you know, effective oil-water interactions.
- There's a process going on. Okay, so it feels like there's
a direction to a process, like a directed process. - There are directions to processes, yeah. And if you're starting with CO2 and you've got two reactive
fluids being brought together, and they react, what are they gonna make? Well, they make carboxylic acids, which include the fatty acids that make up the cell membranes, and they form directly
into bilayer membranes, they form like soap bubbles. It's spontaneous organization caused by the nature of the molecules. And those things are capable of growing and are capable, in effect, of being selected even
before there are genes. We have this, so we have a lot of order, and that order is coming
from thermodynamics. And the thermodynamics, it is always about increasing
the entropy of the universe. But 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, not miscible. Now, to come back to your first question about panspermia properly, that just pushes the
question somewhere else, even if it's true. Maybe life did start
on Earth by panspermia, but so what are the principles that govern the emergence
of life on any planet? It's an assumption that life started here, and it's an assumption that, 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 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. - But the fundamental
question of panspermia is, do we have the machine here
on Earth to build life? Is the vents enough? - 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] Yes. - Well, (chuckles)
(Nick laughs) of course you would say that as a human.
- Yeah. - But there could be
aliens right now chuckling at that idea. Maybe you need some special sauce, special elsewhere sauce.
- Well, yes. - So your sense is we
have everything here. - I mean, this is precisely the question. So I like to, when I'm talking in schools, I like to start out with the idea of we can make a time machine, we go back 4 billion years, and we go to these environments
that people talk about. We go to a deep sea hydrothermal vent, we go to a kind of
Yellowstone-park-type place environment, and we find some slime that
looks like we can test it, it's made of organic molecules. It's got a structure which
is not obviously cells, but, you know, is this a stepping stone
on the way to life or not? - Yeah.
- How do we know? Unless we've got an intellectual framework that says 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, what to look for, how to say this. So all we can ever hope for, 'cause 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. 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? And so if you come up with, you know, it's a long hypothesis, 'cause 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 'cause it means that you have to go out
and do some experiments and try and demonstrate that
it's possible or not possible. - It's so freaking amazing 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. 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] I mean, that's a perception. - That's our romanticization
of things are always better, (chuckles) things are getting better, we'd like to believe that. - I mean, you think about the world from the point of view of bacteria, and bacteria were the
first things to emerge from whatever environment they came from. And they dominated the
planet very, very quickly. And they haven't really changed. 4 billion years later,
they look exactly the same. - So about 4 billion years ago, bacteria started to really run the show. - Yeah.
- And then nothing happened for a while. - Nothing happened for 2 billion years. Then after 2 billion years, we see another single event, origin, if you like, 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 emerged 4 billion years ago. And something happened
2 billion years ago, but the bacteria themselves didn't change, they remained 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 the planet could be full
of bacteria and nothing else. - 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 take that time machine, and you said, asking
yourself the question, is this a stepping stone towards life? As you step along, when you see the early bacteria, how would you know it's life? And then this is really important question when you go to other
planets and look for life. Like, what is the framework of telling a difference
between a rock and a bacteria? - 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] Those are the most fun questions. - The processes of time.
- What do you mean there's no answer? - No, there is no, I mean, there's lots out there, at least 40 or 50 different
definitions of life out there. And most of them are, well- - [Lex] Not convincing. - Obviously bad in one way or another. (Lex laughs) I mean, there's, I can never remember the
exact words that people use, but there's a NASA working
definition of life, which more or less says a
system which is capable, 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, you know, I know
what they're getting at, I know what they're trying to say, but I pick a hole in that. And there's, you know,
there's always wags who say, you know, by that definition, a rabbit is not alive, only a pair of rabbits would be alive, 'cause a single rabbit is
incapable of copying itself. There are all kinds of pedantic, silly, but also important
objections to any hypothesis. The real question is what is, you know, we can argue all day, or people do argue all day about, is a virus alive or not? And it depends on the content. Most biologists could
not agree about that. So then what about a jumping gene, a retro element or something like that, it's even simpler than a virus, but it's capable of
converting its environment into a copy of itself. 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 able to
parasitize the environment, and that goes for plants
as well as animals and bacteria and viruses, to make a relatively
exact copy of themselves, informationally exact copy of themselves. - 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. Like, the way evolution is.
- Ah... - So, it is extremely
powerful process of evolution, which is basically make a copy yourself and sometimes mess up. - Yes, absolutely.
- A little bit. Okay, that seems to work really well. I wonder if it's possible to- - [Nick] Mess up big time. - Mess up big time as a standard, that's the default. - Ah, it's called the hopeful monster, and, you know- - [Lex] It doesn't work. - In principle, it can. Actually, it turns out, I would say that this
is due a reemergence, there's some amazing
work from Michael Levin, I don't know if you came across him, but if you haven't interviewed him, you should interview him. - Yeah, yeah, in Boston. - [Nick] About, yeah, yeah. - I'm talking to him in a few days. - [Nick] Oh, fantastic. (both laughing) - So I mentioned off- - Yeah, so he's-
- There's two people that Andrej, if I may, mentioned. Andrej Karpathy is a friend who's really admired in the AI community, said, "You absolutely must
talk to Michael and to Nick." 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. - Well, Michael Levin
is doing amazing work, basically about the way in which electrical fields
control development. 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 new head. But the head that they develop depends if you knock out just one
iron 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 head. Now, that is really, you might say, a hopeful monster. This is 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, you know, a shift. But for it to be a
speciation for it to continue for it to give rise to a
different morphology over time, then it has to be perpetuated. So that shift, that change in that one gene, has to work well enough that
it is selected and it goes on. - And copied enough times to where you can really test it.
- Yeah, yeah. - So the likelihood, it would be lost, but there'll be some
occasions where it survives, and yes, the idea that we can have sudden fairly
abrupt changes in evolution, I think it's time for a rebirth. - What about this idea that kinda 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. - Ah!
- Do you find that at all compelling?
- I like that view because I think that in a sense that's not very far away from what a hypothesis needs to do to be a testable hypothesis
for the origin of life, you need to spell out, here's each step 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, you know, we'll have created
life within five years," but, you know, ask them
what they mean by life. We have a planet 4 billion years ago with these vent systems across the entire surface of the planet, and 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. But we still need to
constrain those steps, but we've got, you know, a
planet doing similar chemistry. You asked about a trajectory, the trajectory is the
planetary trajectory. The planet has properties, 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 the heat of volcanoes puts out oxidized gases. So the planet is a battery, it's a giant battery. And we have 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
micro version of the planet. And there is a trajectory in all of that. And there's an inevitability that certain types of
chemical reaction are going to be favored over others. And there's an inevitability
in what happens in water, the chemistry that happens in water. Some will be miscible with water and will form membranes and
will form insoluble structures, and, you know, water, nobody really understands water very well. And it's another big question, for experiments on the origin of life, what do you put it in? What kind of structure do we
want to induce in this water? Because the last thing it's likely to be is just kind of bulk water. - How fundamental is water
to life, would you say? - I would say pretty fundamental. I wouldn't like to say it's impossible for life to start any other way, but water is everywhere. Water's extremely good at what it does, and carbon works
(Lex laughs) in water especially well. And carbon is everywhere. So those things together make me think, probabilistically, if we
found a thousand life forms, 995 of them would be
carbon-based and living in water. - Now the reverse question, if you found a puddle of water
elsewhere and some carbon, no, just a puddle of water. Is a puddle of water a
pretty damn good indication that life either exists here or has once existed here? - [Nick] No. - So it doesn't work the other way. - I think you need a living planet. You need a planet which is capable of turning over its surface. It needs to be a planet with water. It needs to be capable 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 is kind of thermodynamics all the way. - 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, what is, how much variety is there? You kinda spoke to this trajectory, that the environment dictates, like, chemically, I don't know in which other way, spiritually, (laughs)
(Nick chuckles) like, dictates kind of the direction of this giant machine that seems chaotic, but it does seem to have order
in the steps it's taking. How much, how often will life, how often will bacteria emerge? How often will something
like humans emerge? How much variety do you
think there would be? - I think, at the level of bacteria, not much variety. I think we would get, how many times did you
say you wanna run it, a million times?
- A million. - I would say at least a few hundred thousand
would get bacteria again. - [Lex] Oh, wow! Nice. - Because I think there's
some level of inevitability that a wet, rocky planet will give rise through the same processes to something very... I think, this is not something I'd
have thought a few years ago, but working with a PhD student
of mine, Stuart Harrison, he's been thinking about the genetic code, and we've just been publishing on that. There are patterns that you
can discern in the code, or he has discerned in the code, that if you think about them in terms of we start with CO2 and hydrogen, and 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 without it just being transferred across.
- Oh! That's really promising. Some inevitability about the whole of the beginnings of life, in my view. - That's really promising, because if the basic
chemistry is tightly linked to the genetic code, that means we can interact with other life if it exists out there. - Well, that's potentially. - That's really exciting.
- Yes. - [Lex] If that's the case. Okay, but then bacteria- - We've got then, we've got bacteria. - [Lex] Yeah. - How easy is photosynthesis? Much harder, I would say. - Let's actually go there. Let's go through the inventions. - [Nick] Yeah. - What is photosynthesis, and why is it hard? - 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, you know, the single greatest
planetary pollution event in the whole history of the Earth. - The pollutant being oxygen. - Yes, yeah. It also made possible animals. You can't have large active animals without an oxygenated atmosphere, at least not in the sense
that we know on Earth. - So that's a really big invention in the history of Earth.
- Huge invention, yes. And it happened once. There's a few things that
happened once on Earth, and, you know, you're always
stuck with this problem, is once it happened, did it become so good so quickly that it precluded the same
thing happening ever again? Or are there other reasons? And we really have to
look at each one in turn and think, 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 kinda cause an
explosion right at the site, requires really careful wiring. And that wiring, it can't be easy to get it right because, you know, (chuckles) the plants that we see around us, they have chloroplast. Those chloroplasts were
cyanobacteria ones. Those cyanobacteria are
the only group of bacteria that can do that type of photosynthesis. So there's plenty of opportunity. - So there's not even many bacteria. So who invented photosynthesis? - The cyanobacteria, or their ancestors. - [Lex] And there's not many- - No other bacteria can do what's called oxygenic photosynthesis. Lots of other bacteria can split, I mean, you can take 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. 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+, which now precipitates as rust. And you take a proton from
the acidic early ocean, stick it there, now you
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. - That seems, like, extremely unlikely and it's extremely essential for the evolution of complex organisms because of all the oxygen. - Yeah, and that didn't
accumulate quickly either. - 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. - Both resources needed for animals. We need to eat, and we need to burn the food. And we're eating plants, which are getting their
energy from the sun, and we're burning it
with their waste product, which is the oxygen. So there's a lot of kind
of circularity in that, but without an oxygenated planet, you couldn't really have predation. 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 know them. - Well, let's actually step back. What about your eukaryotic versus prokaryotic cells, prokaryotes? How big, what are each of those, and how big of an invention is that? - I personally think that's
the single biggest invention in the whole history of life. - [Lex] It's exciting. (chuckles) So what are they, can you explain? - Yeah, so I mentioned
bacteria and archaea, these are both prokaryotes. 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. In terms of their molecular
machinery, they're amazing. In terms of their morphological appearance under a microscope, they're really small and really simple. The earliest life that
we can physically see on the planet are stromatolites, which are made by things
like cyanobacteria, and they're large superstructures, effectively biofilms plated
on top of each other. And you end up with quite large structures that you can see in the fossil record. But they don't, they never came up with animals, they never came up with plants. They came up with multicellular 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. And I think that that transformed the energetic
possibilities of life. So what we end up with is
kind of a 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 multi-bacterial power without the overhead. So you've got a cell, and it's got bacterial 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 express, 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. - So mitochondria is, like you said, is the bacteria that got inside a cell and then threw away all
this stuff it doesn't need to survive inside the cell, and then kept what? - So what we end up with, so it kept always a handful of genes. In our own case, 37 genes. But there's a few protists, which are single cells, things that have got as
many as 70 or 80 genes, so it's not always the same, but it's always a small number. And you can think of it
as a pared-down power pack where the control unit is really being, has been kind of pared
down to almost nothing. So it's putting out the same power, but the investment 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 amount of power you have to convert those genes into proteins. We've gone up about fourfold
in the number of genes, but in terms of the size of genomes and your ability to make
the building blocks, make the proteins, we've gone up a
hundred-thousandfold or more. So it's huge step change in
the possibilities of evolution. And it's interesting then
that the only two occasions that complex life has arisen on Earth, plants and animals, fungi you could say are complex as well, but they don't form
such complex morphology as plants and animals, start with a single cell. They start with an oocyte
and a sperm fused together to make a zygote. So you start development
with a single cell, and all the cells in the
organism have identical DNA. And you switch off, 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 different cells that are all fighting each other. And so it works. The trouble with bacteria
is they form these biofilms, and they're all genetically different, and effectively they're incapable of that level of cooperation
they would get in a fight. - Okay, so why is this
such a difficult invention, of getting this bacteria inside and becoming an engine
which the mitochondria is, why was that? 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? - Both. It had a huge impact on life because if that had not happened, you can be certain that life on Earth
would be bacterial only. - And that took a really long time. - It took 2 billion years. And it hasn't happened since, to the best of our knowledge. So it looks as if it's
genuinely difficult. And if you think about it then from just an informational perspective, you think, bacteria have got, 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 metagenome where other E. coli out there
have got different gene sets, and they can switch them
around between themselves. And so you can generate a
huge amount of variation, and, you know, they've got more, an E. coli metagenome is
larger than the human genome. We own 20,000 genes or something. So, and they've had 4
billion years of evolution to work out what can I
do and what can't I do with this metagenome. 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've got much larger populations. And they never got around this problem. So why can't they, it seems as if you can't solve
it with information alone, so what's the problem? The problem is structure. If cells, if the very first cells
needed an electrical charge on their membrane to grow, and in bacteria, 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 there are examples of it, 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, you know, you end
up with a large bacteria with no further development. What you need is to incorporate these electrically charged
power pack units inside with their control units intact and for them not to conflict
so much with the host cell 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 an asymmetry. You now have a giant nuclear genome surrounded by lots of
subsidiary energetic genomes that do all the, they're the control units
that are doing all the control of energy generation. - Could this have been done gradually, or does it have to be done that the power pack has to be all intact and ready to go and work? - I mean, it's a kind of step-changing the possibilities of evolution, but it doesn't happen overnight. It's gonna still require
multiple, multiple generations. So it could take, you know, it could take millions of years. It could take shorter time, 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 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? 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 gametes? All eukaryotes do it that way. So, again, you know, (chuckles) why switch? What are the drivers here? So 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 new design. You've got new potential
that you didn't have before. - So the cell living inside another cell, that design allows for better
storage of information, better use of energy, more delegation, like a hierarchical
control of the whole thing, and then somehow that leads to ability to have multi-cell organisms? - I'm not sure that you have hierarchical
control necessarily, but you've got a system where you can have a much larger information
storage depot in the nucleus, you can have a much larger genome. And that allows multicellularity, yes, because it allows you... It's a funny thing, to have 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 gotta have all those
genes in the egg cell at the very beginning, and you gotta have a program
of development which says, okay, you guys switch off those genes and switch on those genes, and you guys, you do that, but all the genes are
there at the beginning. That means you gotta have
a lot of genes in one cell and you gotta be able to maintain them. And the problem with bacteria
is they don't get close to having enough genes in one cell. So 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. - That's really, really tough to do. - Yeah, we know they don't
because it doesn't exist. - We have the data, as far as we know. I'm sure there's a few, like, special ones and they die off quickly. I'd love to know some of the most fun things
bacteria have done since. - Oh, there's a few, I mean, they can do some pretty funky things. And this is a big,
(Lex laughs) this is a broad brush stroke
that I'm talking about, but it's, yeah.
- Yes, generally speaking. So another, you know, fun invention, us humans seem to utilize it well but you say it's also
very important early on, is sex. So, what is sex, just asking for a friend,
(Nick laughs) and when was it invented, and how hard was it to invent, just as you were saying, and why was it invented? Why, how hard was it, and when? - I have a PhD student
who's been working on this, and we've just published-
- On sex? - [Nick] A couple of papers on sex, yes, yes, yes.
- Nice. Where do you publish these? So it's biology.
(Nick laughs) Is it biology, genetics journals? - Oh, this is actually PNAS, which is Proceedings of
the National Academy. - So, like, broad, big-picture stuff. - [Nick] Everyone's interested in sex. - Yeah. (laughs)
- And the job of biologists is to make sex dull. - (laughs) Yikes, yeah. That's a beautiful way to put it. Okay, so when was it invented? - It was invented with eukaryotes
about 2 billion years ago. All eukaryotes share the
same basic mechanism, you produce gametes, the gametes fuse together. So a gamete is the egg cell and the sperm. They're not necessarily even
different in size or shape. So the simplest eukaryotes produce what are called motile gametes, they're all like sperm, and they all swim around, they find each other, they fuse together, they don't have kind of 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 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, and then you double everything. So now we have four copies
of the complete genome, and then we crisscross
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 here. That's recombination. And then we go through two
rounds of cell division, so we divide in half so now the two daughter
cells have two copies. And we 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 miosis and syngamy. That's basically sex. 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. - So what about the kind of, you said, find each other, this kind of imperative to find each other.
- Yeah. - What is that? Like, is that- - Well, you've got a few cells together. So the bottom line on
all of this is bacteria, I mean, it's kind of simple when you've figured it out. And figuring it out, this is not me, this is my PhD student Marco Colnaghi. And in effect, if you're doing lateral, you're an E. coli cell, you got 4,000 genes. You wanna scale up to a eukaryotic size, and I wanna have 20,000 genes. 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 it can't grow, I know all my regulation
systems are saying, something wrong here, something wrong, pick up some DNA, pick up a bit of DNA from the environment. If you got a small genome, the chances of you picking
up the right bit of DNA from the environment is much higher than if you got a genome of 20,000 genes. To do that, 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 gotta pick up large chunks, and in the end, you gotta line them up. You're forced into sex, (chuckles) to coin a phrase. So you're- (Lex laughs) So there is a kind of incentive. - If you wanna have a large genome, you've gotta 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 gotta maintain its quality, you gotta stop it just mutating away. - What about sexual selection? So the finding, like, I don't like this one, I don't like this one, this one seems all right. Like, what, at which point does it become less random? - It's hard to know. - [Lex] 'Cause eukaryotes
just kinda float around, just kinda have... - Yeah, I mean, is there sexual selection in singled-celled eukaryotes? There probably is, it's just that I don't know very much about it. By the time we get onto-
- You don't hang out with eukaryotes. (chuckles) - [Nick] Well, I do, all the time. - But you can't communicate with them, yeah.
- Yeah. A peacock or something. - [Lex] Yes. - The kind of standard, this is not quite what I work on, but the standard answer is
that it's female mate choice, she is looking for good genes. And if you can have a
tail that's like this 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 (chuckles) despite this handicap, you are able to survive, so- - 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.
- Yes. - Like how you advertise yourself that you're worthy of...
- Yeah, absolutely. - So one big advertisement is the fact that you survived it all. (chuckles) - That's pretty good.
- Let me give you one beautiful example, of an algal bloom. And this can be a sign of bacteria, this can be in bacteria. So, if suddenly, you know, you pump nitrate or phosphate or something into the ocean, and everything goes green, you end up with all this
algae growing there. 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 do the same things, it's how we have the different, you know, the gaps between
our fingers and so on, it's how we craft synapses in the brain. You know, it's fundamental, again, to multicellular life. They have the same machinery
in these algal blooms. How do they know who dies? The answer is they will
often put out a toxin. And that toxin is 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'll form kind of a resistant spore. You sink down a little bit, you get outta the way, you're 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
trigger your death apparatus, and you kill yourself. - Oh, so it's truly
life-and-death selection. - Yeah. So it's really, it's a challenge, and this is a bit like sexual selection. They're all pretty much
genetically identical, but they've had different life histories. So have you had, you know, a tough day? 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. - It's also actually exactly
the way I approach dating, but that's probably
(Nick laughs) why I'm single, okay. What about if you can step back DNA? Just mechanism of storing information. RNA, DNA.
- Yeah. - How big of an invention was that? 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 with your and your students' work that there's a deep connection
between the chemistry and the ability to have this
kind of genetic information. So how big of an invention is it to have a nice representation, a nice hard drive for info to pass on? - Huge, I suspect. I mean, but when I was
talking about the code, you see the code in RNA as well. An RNA almost certainly came first. And there's been an
idea going back decades called the RNA world, because RNA in theory can copy itself and can catalyze reactions, so it kinda cuts out this
chicken-and-egg loop. - So DNA, it's possible,
is not that special. - So RNA is the thing that
does the work, really. 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 RNA. So getting to RNA, I suspect, is probably not that hard. But getting from RNA, how do you, you know, there's multiple different
types of RNA now, how do you distinguish? This is something we're
actively thinking about, how do you distinguish between, you know, a random population of RNA? Some of them go on to
become messenger RNA, this is the transcript of the code of the gene that you wanna make. Some of them become transfer RNA, which is kind of the unit
that holds the amino acid that's gonna be polymerized. Some of them become ribosomal RNA, which is the machine which is joining them all up together. How do they discriminate themselves? And, you know, is some kind of phase
transition going on there? 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 is 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. 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 got DNA, then you got an amazingly stable molecule for information storage, and you can do absolutely anything. But how likely that transition
from RNA to DNA was, I don't know either. - How much possibility
is there for variety in ways to store information? 'Cause it seems to be very, there's specific characteristics about the programming language of DNA. - Yeah, there's a lot of work going on on what's called xeno DNA or RNA. Can we replace the basis themselves, the letters, if you like, in RNA or DNA? Can we replace the backbone? Can we replace, for example, phosphate with arsenate? Can we replace the sugar ribos or deoxy ribos with a different sugar? And the answer is yes, you can, within limits. There's not an infinite space there. Arsenate doesn't really work if the bonds are not
as strong as phosphate, it's probably quite hard
to replace phosphate. It's possible to do it. The question to me is, why is it this way? 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, and they work? And I'm increasingly
thinking it's that way, that we're channeled
towards ribos, phosphates, and the basis that are used. But there are, you know, 200 different letters
kicking around out there that could've been used. - It's such an interesting question, if you look at in the programming world, in computer science, there's a programming
language called JavaScript, which was written super quickly, it's a giant mess, but it took over the world.
(Nick chuckles) And it was kind of-
- Sounds very biological. - It was kind of a
running joke that, like, surely this can't be, this is 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's usually running JavaScript, and it's now taking over
much of the back-end, which is, like, the serious,
heavy-duty computational stuff and is become super fast with the different compilation
engines that are running it, so it's like it really
took over the world. It's very possible that this initially crappy, derided language actually takes everything over. And then the question is, did human civilization always
strive towards JavaScript, (Nick laughs) or was JavaScript just the
first programming language that ran in the browser, and so it's sticky, the first is the sticky one. And so it wins over anything
else because it was first. And I don't think that's
the answerable, right? But it's good to ask that.
- Yeah. - I suppose in the lab, you can't (chuckles) run it
with programming languages, but in biology you can probably do some kind of small-scale evolutionary test to try to infer which is which. - Yeah, I mean, in a way, we've got the hardware
and the software here. And the hardware is maybe
the DNA and the RNA itself, and then the software perhaps
is more about the code. It's did the code have to be this way, could it have been a different way? - People talk about the
optimization of the code, and there's some suggestion for that. I think it's weak, actually. But you could imagine you could come out with a
million different codes, and this would be one of the best ones. - [Lex] Yeah. Well, we don't know this. We don't know this.
- Well, I mean, people have tried to model
it based on the effect that mutations would have. - [Lex] Ah. - So, no, you're right, we don't know, because that's a single assumption that a mutation is what's
being selected on there. And there's other possibilities too. - I mean, there does
seem to be a resilience and a redundancy to the whole thing. - Yeah.
- It's hard to mess up. And the way you mess it up often is likely to produce interesting results. - So it's- - Are you talking about JavaScript
or the genetic code now? Yeah?
(Lex laughs) Well, I mean, it's almost, you know, biology is underpinned by this kind of mess as well.
- Yeah. - And you look at the human genome, and it is 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. - So what about, you mentioned the predatory behavior. - Yeah.
- We talked about sex. What about violence? Predator and prey dynamics?
(Nick chuckles) When was that invented? And poetic and biological
ways of putting it, like, how do you describe
predator-prey relationship? Is it a beautiful dance, or is it a violent atrocity? - 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 Lynn Margulis used
to talk about a lot. It's got a kind of a drill piece that drills through the wall in the membrane of the bacterium, and then 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. - So predation in that,
sorry to interrupt, means you murder somebody
and use their body as a resource in some way.
- Yes, yeah. - But it's not parasitic in that you need them to be still alive in some way?
- No, no. I mean, predation is
you kill them, really. - Murder, yeah.
- A parasite is, you kind of live on them. (chuckles) - Okay, so, but it seems the predator
is the really popular tool. - So what we see if we go back 560, 570 million years before
the Cambrian explosion, there is what's known
as the Ediacaran fauna, or sometimes they call vendobionts, which is a lovely name. And it's not obvious that
they're animals at all. They're stalked things, they often have fronds
that look a lot like leaves with kind of fractal
branching patterns on them. And the thing is they're found sometimes, geologists can figure out the environment that they were in and say, "This is more than 200 meters deep because there's no sign of any waves, there's, you know, 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. And they're filter feeders, and we know, you know, sponges and corals and things are filter-feeding animals, they're stuck to the spot. And little bits of carbon
that come their way, they filter it out, and that's what they're eating. 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. 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, you know, they're plainly killing things or running away and hiding. And so we've gone from a
rather gentle but limited world to a rather vicious, unpleasant
world that we recognize and which leads to kind of arms races, evolutionary arms races, 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 it does do good. I don't wanna make an
argument for nuclear arms, but predation as a mechanism forces organisms to adapt, to change, to be better, to escape, or to kill. If you need to eat, then you've gotta eat, and, you know, a cheetah's
not gonna run at that speed unless it has to because the zebra is capable of escaping. So it leads to much greater feats of evolution would ever have
been possible without it, and in the end, to a much
more beautiful world. And so it's not all bad
(chuckles) by any means. But the thing is, you can't have this if you don't have an oxygenated planet, because 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. 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 you've gone to 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 chuckles) The history of life on
Earth, unfortunately, is that of violence. Just the trillions and trillions of multi-cell organisms that were murdered in the struggle for survival.
- It's a sorry statement, but, yes, it's basically true. - 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. - I mean, survival of the fittest, if you just go back to that old phrase, means death of the weakest. Now, what's fit, what's weak? These are terms that don't
have much intrinsic meaning. But the thing is, evolution only happens because of death. - One way to die is the constraints, the scarcity of the
resources in the environment, but that seems to be not nearly as good of a 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. - It forces you to come up with a solution to your specific problem
(Lex chuckles) that is inventive and is new and hasn't been done before. And so it forces, I mean, literally change, literally evolution on populations. They have to become different. - 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 controlled competition in the space of ideas, in the space of approaches to life, maybe you can be even more
productive than evolution is, 'cause evolution is very wasteful, like, the amount of murder required to really test a good idea-
- Yeah. - Genetically speaking, is just a lot.
- Yeah, yeah. - Yeah, I mean-
- Many, many, many generations. - Morally, we cannot base society on the way that evolution works. - That's an invention, right? Morality.
- But actually, 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. You know, in ancient Greece, we had the Athens and
Sparta and city states, and then we had the
Renaissance and nation states. And, you know, universities
compete with each other. - Yes.
- Tremendous amount. Companies competing with
each other all the time. It drives innovation. 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, there's some limits, guys, and these are what the
limits are gonna be. And society as a whole has to say, right, we wanna 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 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 innovation
and the richness of it. - And I forgot who said it, but that murder is illegal, probably Kurt Vonnegut,
(Nick chuckles) "Murder is illegal except when it's done to the sound of trumpets
and at a large scale." So we still have wars, 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 get rid of the
stuff that's not productive. So trying to almost accelerate evolution, the same kind of thing that
makes evolution creative, we're trying to use that. - I think we naturally do it. I mean, I don't think we
can help ourselves do it. And, you know, capitalism.
- It's so hard to know. - Capitalism as a form is
basically about competition and differential rewards. But society, you know, we have a, I keep using this word, moral obligation, but, you know, we cannot operate as a
society if we go that way. It's interesting that we've had problems achieving balance. So, for example, 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 in that sense, you don't need the regulation because they just die. 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, in which case you then have to impose some kind of regulation that the bankers themselves will, in an evolutionary manner, exploit. - Yeah, we've been struggling with this kind of idea of capitalism, the cold brutality of capitalism that seems to create so much
beautiful things in this world, and then the ideals of communism that seem to create so much
brutal destruction in history. 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 playing with as opposed to people. If a PhD student has a bad idea, we don't shoot the PhD student, we just criticize their idea
(Nick laughs) and hope they improve. - You have a very humane lab. - Yeah, (chuckles) yeah.
(Nick chuckles) I don't know how you guys do it, you know. The way I run things, it's always life and death. Okay, 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
early invention of sex and early invention of predation, what was the thing
invented to make humans? What would you say? - I mean, I suppose a
couple of things I'd say. Number one is, you don't have to wind
the clock back very far, 5, 6 million years or so, and let it run forwards again, and the chances of humans as we know them is not necessarily that high. And, 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, spacefaring civilization. So when we think about aliens, we're kind of after
something like ourselves, we're after a spacefaring civilization. We're not after zebras and
giraffes and lions and things, amazing, though, they are. But the additional kind
of evolutionary steps to go from large, complex mammals, monkeys, let's say, to humans doesn't strike me as that long a distance, it's all about the brain. And where's the brain
and morality coming from? It seems to me to be all about groups, human groups and
interactions between groups. - The collective intelligence of it. - Yes, the interactions, really. And there's a guy at
UCL called Mark Thomas, who's done a lot of really beautiful work, I think, on this kind of question. So I talk to him every now and then, so my views are influenced by him. 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. The more expertise you are
able to develop and maintain, the more culturally complex
your society can become. And groups that have become detached, like on Easter Island, for example, very often degenerate in terms of the complexity
of their civilization. - Is that true for complex
organisms in general? Population density is often productive.
- Really matters. Really matters, but in human terms, I don't know what the actual factors were that were driving a large brain, but, you know, 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 seems to work much better just 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. - But population density is the thing that increases the number of interactions, but then there must have been inventions forced by that number of interactions that actually led to humans. So like Richard Wrangham 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 chuckles) when you're living
together, they don't like, our early ancestors don't
like the dictatorial aspect of a single individual
at the top of a tribe, so they learn to collaborate how to basically create
a democracy of sorts, a democracy that prevents, minimizes, or lessens the amount of violence, which essentially gives
strength to the tribe and make the war between
tribes versus the dictator. - 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 communism, it is really just two
aspects of human nature, both of which are-
- We got both. - We have both. And we have a constant kind of
vying between the two sides. 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 you could say that's, 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 and
interactions between groups, yes, all this dynamic of if you're interacting between groups, you can be certain that they're
gonna be burning each other and all kinds of 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 are we gonna do to prevent being overrun by those marauding gangs from over there? And you look outside humans and you look at chimps
and bonobos and so on, and they're very, very
different structures to society. Chimps tend to have an aggressive
alpha-male-type structure. And Bonobos are, you know, there's basically a female society, whether males are predominantly excluded and only brought in at
the behest of the female. We have a lot in common
with both, (chuckles) both of those groups.
- Yeah. And there's, again, tension there. And probably chimps, more violence, bonobos, probably more sex. That's another tension. (Nick laughs) - Yes.
(Lex chuckles) - How serious do we wanna be? How much fun we wanna be? Asking for a friend again, what do you think
happened to neanderthals? What did we cheeky humans do to the neanderthals, Homo sapiens? Do you think we murdered them? (chuckles) How do we murder them? How do we out-compete them? Or do we out-mate them? - I don't know. I mean, I think there's unequivocal evidence that we mated with them. - Yeah, we always try
to mate with everything. - Yes, pretty much.
(Lex laughs) There's some interesting, the first sequences that came along were in mitochondrial DNA, and that was back to
about 2002 or thereabouts. And what was found was that
neanderthal mitochondrial DNA was very different to human mitochondrial DNA.
- Oh, that's so interesting. - And you could do a clock on it, and it said the divergent state
was about 600,000 years ago or something like that, so not so long ago. And then the first full
genomes were sequenced maybe 10 years after that. And they showed plenty of
signs of mating between. So the mitochondrial DNA effectively says no mating, (chuckles) and the nuclear genes say, yeah, lots of mating, but we don't know-
- How is that possible? Sorry, can you explain the difference between mitochondrial DNA-
- Sorry, yes. - And nucleus. - I've talked before
about the mitochondria, which are the power packs in cells. These are the pared-down
control units is their DNA. So it's passed on by the mother only. And in the egg cell, we might have half a million copies of mitochondrial DNA. There's only 37 genes left. And they, it's basically the control
unit of energy production, that's what it's doing. - It's a basic old school machine that does energy production.
- And it's got genes that were considered to
be effectively trivial because they did a very
narrowly defined job, but they're not trivial in the sense that that narrowly defined job is about, (chuckles) everything is being alive. - [Lex] Yeah. - So they're much easier to sequence, you got many more copies of these things, and you can sequence them very quickly. But the problem is because they go down
only the maternal line from mother to daughter, your mitochondrial DNA
and mine is going nowhere. Doesn't matter. Any kids we have, they get their mother's mitochondrial DNA, except in very, very rare
and strange circumstances. And so it tells a different story, and it's not a story which
is easy to reconcile always. And what it seems to suggest, to my mind at least, is that there was one-way traffic of genes probably going from
humans into neanderthals rather than the other way round. Why did the neanderthals disappear? I don't know. I mean, I suspect that they were, I suspect they were probably less violent, less clever, less populous, less willing to fight. I don't know. I mean, I think it probably
drove them to extinction at the margins of Europe. (Lex chuckles) - And it's interesting how much, if we ran Earth over and over again, how many of these branches
of intelligent beings that have figured out some kind of how to leverage collective intelligence. Which ones of them emerge, which ones of them succeed? Is it the more violent ones? Is it the more isolated one? You know, like, what dynamics result in more productivity? And I suppose we'll never know. The more complex the organism, the harder it is to run
the experiment in the lab. - Yes, and in some respects, maybe it's best if we don't know. - Yeah, the truth might be very painful. What about if we actually step back a couple of interesting
things that we humans do. One is object manipulation and movement. And of course, movement was
something that was done, that was another big invention, be able to move around the environment. And the other one is
this sensory mechanism, how we sense the environment. One of the coolest
high-definition ones is vision. How big are those inventions in the history of life on Earth? - Vision, movement, I mean, again, extremely important. Going back to the origin of animals, the Cambrian explosion, where suddenly you're seeing
eyes in the fossil record. And you can, it's not necessarily, again, lots of people historically have said, what use is half an eye? And, you know, you can go in a series of steps from
a light-sensitive spot on a flat piece of tissue to an eyeball with a lens and so on if you assume no more than, I don't remember, this was a specific model
that I have in mind, but it was, you know, 1% change or half a percent
change for each generation, how long would it take to
evolve an eye as we know it? And the answer is half a million years. It doesn't have to take long. That's not how evolution works, that's not an answer to the question, it just shows you can
reconstruct the steps and you can work out
roughly how it can work. So it's not that big a
deal to evolve an eye. But once you have one, then there's nowhere to hide. And, again, we're back to
predator-prey relationships, we're back to all the benefits that being able to see brings you. And if you think, you know, philosophically what bats are doing with echolocation and so on, I have no idea, but I suspect that they
form an image of the world in pretty much the same way that we do, it's just a matter of
mental reconstruction. So I suppose the other thing about sight, there are single-celled organisms that have got a lens and a retina and a cornea and so on. Basically, they got a
camera-type eye in a single cell. They don't have a brain. What they understand about their
world is impossible to say, but they're capable of coming up with the same structures to do so. So I suppose then is that once
you've got things like eyes, then you have a big driving pressure on the central nervous system to figure out what it all means. And then we come around
to your other point about manipulation,
sensory input, and so on, now you have a huge requirement to understand what your environment is and what it means and how it reacts and how you should run away and where you should stay put. - Actually, on that point, let me, I don't know if you know the work of Donald Hoffman, who talks about, who uses the argument, the mechanism of evolution to say that there's not necessarily a strong evolutionary value to seeing the world as it is. So, objective reality, that our perception
actually is very different from what's objectively real. We're living inside an illusion. And basically the entire, the entire set of species
on Earth, I think, I guess, are competing in a space that's an illusion that's distinct from, that's far away from physical
reality as defined by physics. - I'm not sure it's an
illusion so much as a bubble. I mean, we have a sensory input which is a fraction of what we could have a sensory input on. And we interpret it in terms of what's useful
for us to know to stay alive. So yes, it's an illusion in that sense, but-
- So it's the subset. - The tree is physically there, and if you walk into that tree, you know, it's not purely a delusion, there's some physical reality to it. - So it's a sensory slice
into reality as it is, but because it's just a slice, you're missing a big picture. But he says that that slice
doesn't necessarily need to be a slice. It could be a complete fabrication that's just consistent
amongst the species, which is an interesting or at least it's a humbling realization that our perception is limited and our cognitive abilities are limited. And at least to me, his argument, from evolution, I don't know how much, how strong that is as an argument, but I do think that life
can exist in the mind. - Yes.
- In the same way that you can do a virtual
reality video game and you can have a vibrant
life inside that place. And that place is not real in some sense, but you could still have a vibrant, all the same forces of evolution, all the same competition, the dynamics between humans you can have, but I don't know if, I don't know if there's evidence for that being the thing
that happened on Earth. It seems that Earth- - I think in either environment, I wouldn't deny that you could have exactly the world that you talk about. And it would be very difficult to, you know, the idea in
"Matrix" movies and so on, that the whole world is completely
(chuckles) a construction and we're fundamentally deluded. It's difficult to say that's
impossible or couldn't happen, and certainly we construct in our minds what the outside world is, but we do it on input, and that input, I would hesitate to say it's not real, because it's precisely how
we do understand the world. We, you know, we have eyes, but if you keep someone in, apparently this kind of thing happens, someone kept in a dark room for five years or something like that, they never see properly again because the neural wiring that underpins how we interpret vision never developed. You know, you need, when you watch a child develop, it walks into a table, it bangs his head on the table, and it hurts. And (chuckles) now you've got two inputs, you got one pain from this sharp edge, and number two, you probably, you've touched it and realized it's there, it's a sharp edge, and you got the visual input and you put the three
things together and think, I don't wanna walk into a table again. So you're learning, and it's a limited reality but it's a true reality. And if you don't learn that properly, then you will get eaten, you will get hit by a bus, you will not survive. And same if you're in some kind of, let's say computer
construction of reality, I'm not in my ground here, but if you construct the laws that this is what reality is inside this, then you play by those laws. - Yeah, well, I mean, as long
as the laws are consistent. - Yeah.
- So just like you said in the lab, the interesting thing about
the simulation question, yes, it's hard to know if we're
living inside a simulation, but also, yes, it's possible to do these kinds of experiments in the lab now, more and more. To me, the interesting question is, how realistic does a virtual
reality game need to be for us to not be able
to tell the difference? A more interesting question to me is, how realistic or interesting does a virtual
reality world need to be in order for us to want
to stay there forever or much longer than physical reality? Prefer that place. And also prefer it not
as we prefer hard drugs but prefer it in a deep, meaningful way in the way we enjoy life itself. - I mean, I suppose the
issue with "The Matrix," I imagine that it's possible to delude the mind sufficiently that you genuinely, in that way, do think that you are
interacting with the real world when in fact the whole
thing's a simulation. How good does the simulation need to be to be able to do that? Well, it needs to convince you that all your sensory input
is correct and accurate and joins up and make sense. Now, that sensory input is not something that we're born with. We're born with a sense of touch, we're born with eyes, and so on, but we don't know how to use them, we don't what to make of them. We go around, we bump into trees, we cry a lot, we're in pain a lot. We, you know, (chuckles) we're basically booting up the system so that it can make head or tail of the sensory input that it's getting. And that sensory input's not
just a one way flux of things, it's also you have to walk into things, you have to hear things, you have to put it together. Now, if you've got just
babies in "The Matrix" who are slotted into this, I don't think they have
that kind of sensory input, I don't think they would have any way to make sense of New York as a world that they're part of. The brain is just not
developed in that way. - Well, I can't make sense of New York in this physical reality either.
(Nick chuckles) But yeah, I mean, but you said pain and
the walking into things. Well, you can create a pain signal. And as long as it's consistent that certain things result in pain, you could start to construct a reality. There's some, maybe
you disagree with this, but I think we are born almost with a desire to be
convinced by our reality, like a desire to make
sense of our reality. - [Nick] Oh, I'm sure we are, yes. - Like, so there's an imperative, so whatever that reality is given to us, like the table hurts, fire's hot. - [Nick] Yeah. - I think we wanna be deluded in the sense that we
want to make a simple, like, Einstein's simple
theory of the thing around us. - Yeah.
- We want that simplicity. And so maybe the hunger for
the simplicity is the thing that could be used to construct
a pretty dumb simulation that tricks us. So, maybe tricking humans doesn't require building
a universe. (laughs) - No, I don't, I mean, this is not what I work on, so I don't know how close to it we are.
- I don't think anyone works on it.
- But I agree with you that- - Mark Zuckerberg.
- Yeah, I'm not sure that it's (chuckles) a morally justifiable thing to do, but is it possible in principle? I think it'd be very difficult. But I don't see why in principle
it wouldn't be possible, and I agree with you that we
try to understand the world, we try to integrate the
sensory inputs that we have, and we try to come up with a hypothesis that explains what's going on. I think, though, that we have huge input from the social context that we're in. We don't do it by ourselves, we don't kinda blunder around
in a universe by ourself and understand the whole thing. We're told by the people around us what things are and what they do, and, you know, languages
coming in here and so on. So, it would have to be an
extremely impressive simulation to simulate all of that. - Yeah, simulate all of that, including the social construct, the spread of ideas and
the exchange of ideas, I don't know. But those questions are
really important to understand as we become more and
more digital creatures. It seems like the next step
of evolution is us becoming, all the same mechanisms we've talked about are becoming more and more
plugged in into the machine. We're becoming cyborgs. And there's an interesting interplay between wires and biology. You know, zeros and ones
and the biological systems. And I don't think you can just, I don't think we'll have the luxury to see humans as disjoint from the technology we've
created for much longer. We are an organism that's merged. - Yeah. I mean, I agree with you, but we come really with
this consciousness. - [Lex] Yes. - And is there a distinction there? Because what you're saying, the natural endpoint says
we are indistinguishable, that if you are capable of building an AI which is sufficiently close and similar that we merge with it then, then to all intents and purposes, that AI is conscious, as we know it. And I don't have a strong view, but I have a view. (chuckles) And I wrote about it in the
epilogue to my last book, because 10 years ago, I wrote a chapter in a book called "Life
Ascending" about consciousness. And the subtitle of "Life Ascending" was "The Ten Great
Inventions of Evolution," and I couldn't possibly write a book with a subtitle like that that did not include consciousness, and specifically consciousness as one of the great inventions. And it was in part because I
was just curious to know more, and I read more for that chapter. I never worked on it, but I've always, how can anyone not be
interested in the question? And I was left with the feeling that, A, nobody knows, and B, there are two main
schools of thought out there with a big kind of skew in distribution. One of them says, oh,
it's a property of matter. It's an unknown law of physics. Panpsychism, everything is conscious, the sun is conscious, it's just a matter, or a rock is conscious, it's just a matter of how much. And I find that very unpersuasive. I can't say that it's wrong, it's just that I think we
somehow can tell the difference between something that's living
and something that's not. And then the other end is, it's an emergent property of a very complex central nervous system. And I never quite
understand what people mean by words like emergence. I mean, there are genuine examples, but I think we very often tend to use it to plaster over ignorance. As a biochemist, the
question for me then was, okay, it's a concoction of
a central nervous system. A depolarizing neuron
gives rise to a feeling, to a feeling of pain or to a feeling of love or anger, whatever it may be. So what is then a feeling
in biophysical terms in the central nervous system, which bit of the wiring gives rise to? And I've never seen anyone
answer that question in a way that makes sense to me. - And that's an important
question to answer. - I think if we wanna
understand consciousness, that's the only question to answer, because, you know, certainly an AI is
capable of out-thinking, and it is only a matter of time. Maybe it's already happened. In terms of just information processing and computational skill, I don't think we have any problem in designing a mind which
is at least the equal of the human mind. But in terms of what we
value the most as humans, which is to say our
feelings, our emotions, our sense of what the world is in a very personal way, that, I think, means as
much or more to people than their information processing. And that's where I don't think that AI necessarily will become conscious, because I think it's a property of life. - Well, let's talk about it more. You're an incredible writer, one of my favorite writers, so let me read from your
latest book, "Transformers," what you write about consciousness. "'I think therefore I am' said Descartes. It's one of the most
celebrated lines ever written. But what am I, exactly? An artificial intelligence can think too, by definition, and therefore 'is.' Yet few of us could agree whether
AI is capable in principle of anything resembling human emotions, of love or hate, fear and joy, of spiritual yearnings
for oneness or oblivion, or corporeal pangs of thirst and hunger. The problem is we don't
know what emotions are," as you were saying. "What is a feeling in physical terms? How does a discharging neuron give rise to a feeling of anything at all? This is the 'hard
problem' of consciousness, the seeming duality of mind and matter, the physical makeup of our innermost self. We can understand in principle how an extremely sophisticated
parallel processing system could be capable of wondrous
feats of intelligence, but we can't answer in principle whether such a supreme
intelligence would experience joy or melancholy. What is a quantum of solace?" (Nick chuckles) Speaking to the question of emergence, you know, there's just technical, there's an excellent paper
on this recently about this kind of phase transition, emergence of performance
in neural networks on the problem of NLP,
natural language processing. So language models, there seems to be this question of size. At some point, there is a phase transition as you grow the size
of the neural network. So the question is, this is sort of somewhat
of a technical question that you can philosophize over. The technical question is, is there a size of a neural network that starts to be able to form
the kind of representations that can capture a language and therefore be able to not just language but linguistically capture
knowledge that's sufficient to solve a lot of problems in language, like be able to have a conversation? And there seems to be
not a gradual increase, but a phase transition. And they're trying to
construct the science of where that is. Like, what is a good
size of a neural network, and why does such a
phase transition happen? Anyway, that sort of points to emergence, that there could be stages where a thing goes from being, oh, you're a very intelligent toaster, (Nick chuckles) to a toaster that's feeling sad today and turns away and looks
out the window, sighing, having an existential crisis.
(Nick chuckles) - I'm thinking of Marvin the
Paranoid Android. (chuckles) - Yeah, exactly. Well, no, Marvin is simplistic because Marvin is just cranky. - [Nick] Yes. So, easily programmed. - Yeah, easily programmed, nonstop existential crisis. You're almost basically, what is it, "Notes from Underground" by Dostoevsky, it's just constantly
complaining about life. No, capturing the full
rollercoaster of human emotion. The excitement, the bliss, the connection, the empathy, and all that kinda stuff, and then the selfishness, the anger, the depression, all that kinda stuff. Capturing all of that and be able to experience it deeply. Like, it's the most important thing you could possibly experience today. The highest highs, the lowest lows, this is it. My life will be over. I cannot possibly go on, that feeling, and then, like, after a nap, (chuckles) you're feeling amazing. That might be something that emerges. - So why would a nap make
an AI being feel better? - First of all, we don't know that for a human either, right? - But we do know that it's actually true for many people much of the time. Maybe you're utterly depressed- - Oh, you mean-
- And you have a nap and you do in fact feel
better, so. (chuckles) - Oh, you are actually asking
the technical question there. So there's a biological answer to that. And so the question is whether AI needs to have the same kind of
attachments to its body, bodily function and preservation of the brain's successful function. Self-preservation, essentially, in some deep biological sense. - I mean, to my mind, it comes back round to the problem we were talking about before about simulations and sensory input and learning what all of this stuff means, and life and death. That biology, unlike society, has a death penalty over everything. And natural selection works
on that death penalty, that if you make this decision wrongly, you die. And the next generation is represented by beings that made a
slightly different decision. (chuckles) Unbalance. And that is something that's
intrinsically difficult to simulate in all its richness, I would say. So what is... - Death in all its richness? - [Nick] Yeah. - Our relationship with death, or the whole of it. So when you say richness, of course, there's a lot in that. - Yeah.
- Which is hard to simulate? What's part of the richness
that's hard to simulate? - I suppose the complexity
of the environment and your position in that, or the position of an
organism in that environment, in the full richness of that environment over its entire life, over multiple generations with changes in gene sequence
over those generations, so slight changes in the makeup of those individuals over generations. But if you take it back to
the level of single cells, which I do in the book and ask, how does a single cell in effect know it exists as a unit, as an entity? I mean, no, in inverted commas, obviously it doesn't know anything, but it acts as a unit and it acts with astonishing
precision as a unit. And I had suggested that that's linked to the electrical fields on the membranes themselves and that they give some indication of how am I doing in
relation to my environment as a kind of real-time
feedback on the world. And this is something physical which can be selected over generations, that if you get this wrong, (chuckles) it's linked with this set of circumstances that I've just, as an individual, I have a moment of blind
panic and run. (chuckles) As a bacterium or something, you have, you know, some
electrical discharge that says blind panic, and it runs, whatever it may be. And you associate over generations, multiple generations that
this electrical phase that I'm in now is associated with (chuckles) a response like that. And it's easy to see how feelings come in through the back door
almost with that kind of giving real-time feedback on
your position in the world in relation to how am I doing. And then you complexify the system, and yes, I have no problem
with a phase transition. And, you know, can all of this be done purely by the language, by the issues with how the
system understands itself? Maybe it can, I honestly don't know. But, you know, the philosophers for a long time have talked
about the possibility that you can have, you
know, zombie intelligence, and that there are no feelings there but everything else is the same. I mean, I have to throw
this back to you, really. How do you deal with
a zombie intelligence? - (chuckles) So, first of all, I can see that from a
biologist perspective, you think of all the complexities that led up to the human being, the entirety of the
history of 4 billion years that in some deep sense
integrated the human being into this environment. And that dance of the
organism and the environment, you could see how
emotions arise from that. And then emotions are deeply connected in creating a human experience. And from that you mix in consciousness and the full mess of it, yeah. But from a perspective of
an intelligent organism that's already here, like a baby that learns, it doesn't need to learn how to be a collection of cells or how to do all the
things he needs to do. The basic function of a baby as it learns is to interact with its environment, to learn from its environment, to learn how to fit in
to the social society, to like- - And the basic response of the baby is to cry a lot of the time. - To cry.
(Nick chuckles) Well, maybe convince
the humans to protect it or to discipline it,
to teach it, whatever. I mean, we've developed a
bunch of different tricks, how to get our parents to take care of us, to educate us, to teach us about the world. Also, we've constructed
the world in such a way that it's safe enough for us to survive in and yet dangerous enough for
learn the valuable lessons, like the tables are
still hard with corners, so we can still run into them, it hurts. So AI needs to solve that problem, not the problem of constructing this super complex organism that leads up to run the whole... You know, to make an apple pie, to build the whole universe, you need to build the whole universe. (Nick chuckles)
I think the zombie question, it's something I would
leave to the philosophers. (Nick chuckles) Because... And I will also leave to
them the definition of love and what happens between two human beings when there's a magic that just grabs them like nothing else matters in the world, and somehow you've been searching for this feeling, this moment, this person your whole life. That feeling, the philosophers can have
a lot of fun with that one and also say that that's just, you could have a biological explanation, you could have all kinds of, it's all fake, it's actually... Ayn Rand will say it's all selfish. There's a lot of
different interpretations. I'll leave it to the philosophers. The point is the feeling
sure as hell feels very real. And if my toaster makes me feel like it's the only toaster in the world, (Nick chuckles) and when I leave and I miss the toaster, and when I come back, I'm excited to see the toaster and my life is meaningful and joyful, and the friends I have around
me get a better version of me because that toaster exists,
(Nick chuckles) that sure is hell feels like a conscious toaster.
- I mean, is that psychologically different to having a dog? - No, no.
- Because, I mean- - Exactly.
- Most people would dispute whether we can say a dog, I would say a dog is
undoubtedly conscious, but some people would say it isn't. - There's degrees of
consciousness and so on, but people are definitely
much more uncomfortable saying a toaster can be conscious than a dog.
- Yes, yes. - And there's still a deep connection, and you could say our
relationship with a dog has more to do with anthropomorphism. Like, we kinda project
the human being onto it. - [Nick] Maybe. - We can do the same damn
thing with a toaster. - Yes, but you can look
into the dog's eyes and you can see that it's sad, that it's delighted to see you again. I don't have a dog, by the way. It's not that I'm a dog person or a cat person.
- And dogs are actually incredibly good at using
their eyes to do just that. - Yeah, they are. Now, I don't imagine that
a dog is remotely as close to being intelligent
as an AI intelligence, but it's certainly capable of communicating emotionally with us. - But here's what I would venture to say, we tend to think because
AI plays chess well and is able to fold proteins now, well, that it's intelligent. I would argue that in order
to communicate with humans, in order to have emotional intelligence, it actually requires
another order of magnitude of intelligence. It's not easy to be flawed. Solving a mathematical
puzzle is not the same as the full complexity of
human-to-human interaction. That's actually, we humans just take for granted the things we're really good at. Nonstop, people tell me how
shitty people are at driving. No, humans are incredible at driving. Bipedal walking, walking, object manipulation, we're incredible at this. And so people tend to- - Discount the things we
all just take for granted. - And one of those things that
they discount is our ability, the dance of conversation and
interaction with each other, the ability to morph ideas together, the ability to get angry at each other and then to miss each other. Like, to create a tension that makes life fun and difficult and challenging in a
way that's meaningful, that is a skill that's learned, and AI would need to solve that problem. - I mean, in some sense, what you're saying is AI cannot become meaningfully
emotional, let's say, until it experiences some
kind of internal conflict that is unable to reconcile these various aspects of
reality or its reality with a decision to make. And then it feels sad necessarily because (chuckles)
doesn't know what to do. And I certainly can't dispute that, that may very well be how it works. I think the only ways
to find out is to do it. - To build it, yeah. And leave it to the philosophers if it actually feels sad or not. The point is, the robot will be sitting there alone, having an internal conflict
and existential crisis, and that's required for it to have a deep,
meaningful connection with another human being. Now, does it actually feel that? I don't know. - But I'd like to throw
something else at you, which troubles me on reading it, Noah Harari's book "21
Lessons for the 21st Century." And he's written about this kind of thing on various occasions. And he sees biochemistry as an algorithm, and then AI will necessarily be able to hack that algorithm and
do it better than humans. So there will be AI
better at writing music that we appreciate than Mozart ever could or writing better than
Shakespeare ever did, and so on. Because biochemistry is algorithmic, and all you need to do is figure out which bits of the algorithm to play to make us feel good or
bad or appreciate things. And as a biochemist, I find that argument (sighs) close to irrefutable
and not very enjoyable. I don't like the sound of it, that's just my reaction as a human being. You might like the sound of it because that says that AI is capable of the same kind of emotional feelings about the world as we are, because the whole thing is an algorithm and you can program an algorithm, and there you are. He then has a peculiar final chapter where he talks about consciousness
in rather separate terms, and he's talking about
meditating and so on and getting in touch
with his inner conscious. I don't meditate, I don't know anything about that. But he wrote in very
different terms about it, as if somehow it's a way
out of the algorithm. Now, it seems to me that
consciousness in that sense is capable of scuppering the algorithm. I think, in terms of the biochemical
feedback loops and so on, it is undoubtedly algorithmic, but in terms of what we decide to do, it can be much more based on an emotion. We can just think, ah, I don't care, I can't resolve this complex situation, I'm gonna do that. And that can be based on, in effect, a different currency, which is the currency of
feelings and something where we don't have very
much personal control over. And then it comes back around to you and what are you trying to get at with AI? Do we need to have some system which is capable of
overriding a rational decision which cannot be made because there's too much
conflicting information by effectively an emotional
judgmental decision that just says, do this
and see what happens. - Yeah, so-
- That's what consciousness is really doing, in my view. - Yeah, and the question is
whether it's a different process or just a higher level process. You know, the idea that
biochemistry is an algorithm is, to me, an oversimplistic view. There's a lot of things that the moment you say it, it's irrefutable, but it simplifies- - [Nick] I'm sure it's
an externally complex- - And in the process loses
something fundamental. So for example, calling a universe an
information processing system. Sure, yes. You could make that, it's a computer that's
performing computations. But you're missing the process of the entropy somehow leading to pockets of complexity that creates these beautiful artifacts that are incredibly complex, and they're, like, machines. And then those machines, through the process of evolution, are constructing even further complexity. Like, in calling universe
information processing machine, you're missing those little local pockets and how difficult it is to create them. So the question to me is, if biochemistry is an algorithm, how difficult is it to
create a software system that runs the human body, which I think, I think that is going to take so long. I mean, that's going to
be centuries from now, to be able to reconstruct a human. Now, what I would venture to say to get some of the magic of a human being with what we were saying with the emotions and the interactions and like a dog makes a smile and joyful and all those kinds of things, that will come much sooner. But that doesn't require us to reverse-engineer the
algorithm of biochemistry. - Yes, but the toaster
is making you happy. - [Lex] Yes. - It's not about whether
you make the toaster happy. - No, it has to be. It has to be. It has to be. The toaster has to be able to leave me.
- The toaster has to be happy. Yes, but it's the toaster as the AI in this case, it's a very intelligent toaster?
- Yeah, the toaster has to be able to be unhappy and leave me. (Nick laughs) That's essential. - Yeah.
- That's essential for my being able to miss the toaster. If the toaster is just my servant or a provider of, like, services, like, tells me the weather, makes toast, that's not going to deep connection. It has to have internal conflict. You write about life and death. It has to be able to be
conscious of its mortality and the finiteness of its existence and that life for it is temporary and therefore it needs
to be more selective kind of people it hangs out.
- One of the most moving moments in the movies
from when I was a boy was the unplugging of HAL in "2001," where that was the death
of a sentient being, and HAL knew it. So I think we all kind of know that a sufficiently intelligent being is going to have some
form of consciousness, but whether it would be like
biological consciousness, I just don't know. And if you're thinking about
how do we bring together, I mean, obviously we're going to interact more closely with AI, but are we really? Is a dog really like a toaster, or is there really some
kind of difference there? You were talking, you know,
biochemistry is algorithmic, but it's not single algorithm
and it's very complex, of course it is. So it may be that there are, again, conflicts in the circuits of biochemistry, but I have a feeling that
the level of complexity of the total biochemical system at the level of a single
cell is less complex than the level of neural networking in the human brain or in an AI. - Well, I guess I assumed that we were including the brain in the biochemistry algorithm, because you have to- - I would see that as a higher level of organization of neural networks, they're all using the
same biochemical wiring within themselves. - Yeah, but the human
brain is not just neurons, it's the immune system, it's the whole package. I mean, to have a biochemical algorithm that runs a intelligent biological system, you have to include the whole damn thing. And it's pretty fascinating
that it comes from an embryo. (chuckles) Like, the whole, I mean, boy, I mean, if you can, what is a human being? 'Cause it's-
- But if you look- - It's just some code, and then you build. So DNA doesn't just
tell you what to build, but how to build it. I mean, the thing is impressive, and the question is, how difficult is it to reverse-engineer the whole shebang? - [Nick] Very difficult. - I would say it's, (blows) don't wanna say impossible, but, like, it's much
easier to build a human than to reverse-engineer, to build, like, a fake human, human-like thing, than to reverse-engineer the entirety of the process, the evolution- - I'm not sure if we are capable of reverse-engineering the whole thing, if the human mind is
capable of doing that. I mean, I wouldn't be a
biologist if I wasn't trying. - [Lex] Yeah. - But I know I can't
understand the whole problem, I'm just trying to understand
the rudimentary outlines of the problem. There's another aspect, though. You're talking about
developing from a single cell to the human mind and all the subsystems
that are part of it, the immune system and so on. This is something that you'll talk about, I imagine, with Michael Levin. But so little is known, you talk about reverse-engineers. So little is known about
the developmental pathways that go from a genome to going to a fully-wired organism. And a lot of it seems to depend on the same electrical interactions that I was talking about, happening at the level of single cells and its interaction with the environment. There's a whole electrical
field side to biology that is not yet written
into any of the textbooks, which is about how does
an embryo develop into, or a single cell develop
into these complex systems, what defines the head, what defines the immune system, what defines the brain, and so on. That really is written in a language that we're only just
beginning to understand. And frankly, biologists, most biologists are still very reluctant to even get themselves
tangled up in questions like electrical fields
influencing development. It seems like mumbo jumbo
to a lot of biologists, and it should not be, because this is the 21st century biology, this is where it's going. But we're not gonna
reverse-engineer a human being or the mind or any of these subsystems until we understand how this
developmental processes work, how electricity and biology really works, and if it is linked with feelings, with consciousness, and so on. I mean, in the meantime, we have to try, but I think that's where the answer lies. - (blows) So you think it's possible that the key to things like consciousness or some of the more tricky
aspects of cognition might lie in that early development, the interaction of
electricity and biology. - [Nick] Mm. - Electrical fields? Oh boy.
- But we already know the EEG and so on is telling us a
lot about brain function, but we don't know which cells, which parts of a neural network
is giving rise to the EEG, we don't know the basics. The assumption is, I mean, we know it's neural networks, we know it's multiple cells, hundreds or thousands
of cells involved in it. And we assume that it's
to do with depolarization during action potentials and so on. But the mitochondria which are in there have much more membranes than the plasma membrane of the neuron, and there's a much greater
membrane potential. And it's formed in parallel, very often parallel cristae which are capable of reinforcing a field and generating fields
over longer distances. And nobody knows if that plays a role in consciousness or not. There a reasons to argue that it could, but frankly we simply do not know. And it's not taken into consideration. You look at the structure of the mitochondrial
membranes in the brains of, you know, simple things like
Drosophila, the fruit fly, and they have amazing structures. You can see lots of
little rectangular things, they're all lined up in amazing patterns. What are they doing? Why are they like that? We haven't the first clue. - What do you think about organoids and brain organoids and, like, so in a lab trying to study
the development of these in the Petri dish, development of organs? Do you think that's promising? Do you have to look at the whole systems? - I've never done anything like that, I don't know much about it. The people who I've talked to who do work on it say
amazing things can happen and that, you know, a bit
of a brain grown in a dish is capable of experiencing
some kind of feelings or even memories of its former brain. Again, I have a feeling
that until we understand how to control the electrical fields that control development, we're not gonna understand
how to turn an organoid into a real functional system. - But how do we get that understanding? It's so incredibly difficult. I mean, you would have to, I mean, one promising direction, I'd love to get your opinion on this. I don't know if you're familiar
with the work of DeepMind and AlphaFold with
protein folding and so on. Do you think it's possible that that will give us some
breakthroughs in biology, trying to basically simulate and model the behavior of
trivial biological systems as they become complex biological systems? - I'm sure it will. The interesting thing to
me about protein folding is that for a long time, my understanding, this is not what I work on, so I may have got this wrong, but my understanding is that you take the sequence of a protein and you try to fold it, and there are multiple
ways in which it can fold. And to come up with the
correct conformation is not a very easy thing because you're doing it
from first principles from a string of letters, which specify the string of amino acids. But what actually happens is when a protein is
coming out of a ribosome, it's coming out of a charged tunnel, and it's in a very specific environment, which is gonna force this to go there now and then this one to go there and this one to come like that, and so you're forcing a
specific conformational set of changes onto it as it
comes outta the ribosome. So by the time it's fully emerged, it's already got its shape. And that shape depended on
the immediate environment that it was emerging into, one letter, one amino acid at a time. And I don't think that the field
was looking at it that way. And if that's correct, then that's very
characteristic of science, which is to say it asks very
often the wrong question and then does really amazingly
sophisticated analyses on something having never thought to actually think, well,
what is biology doing? And biology's giving you a
charged electrical environment that forces you to be this way. Now, did DeepMind come up through patterns with some answer that was like that? I've got absolutely no idea. It thought to be possible to deduce that from
the shapes of proteins. It would require much greater
skill than the human mind has. But the human mind is capable of saying, well, hang on, let's
look at this exit tunnel and try and work out what shape is this protein going to take, and we can figure that out. - That's really interesting
about the exit tunnel, but, like, sometimes we get lucky. And, like, just like in science, the simplified view or the static view will actually
solve the problem for us. So in this case, it's very possible that
the sequence of letters has a unique mapping to our structure without considering how it unraveled, so without considering the tunnel. And so that seems to be
the case in this situation, where the cool thing about proteins, all the different shapes
it can possibly take, it actually seems to take very specific, unique shapes given the sequence. - That's forced on you by an exit tunnel. So the problem is actually
much simpler than you thought. And then there's a whole army of proteins which change the conformational state, chaperone proteins. And they're only used when there's some presumably issue with how it came out of the exit tunnel, and you wanna do it differently to that. So very often the chaperone
proteins will go there and will influence the
way in which it folds. So, there's two ways of doing it. Either you can look at the structures and the sequences of all the proteins and you can apply an immense mind to it and figure out what the patterns are and figure out what happened, or you can look at the actual
situation where it is and say, well, hang on, it was
actually quite simple. It's got a charged environment, and then it's forced to come out this way. And then a question will be, well, do different ribosomes have
different charged environments? What happens if a chaperone? You know, you're asking a
different set of questions to come to the same answer in a way which is telling
you a much simpler story and explains why it is, rather than saying it could be, this is one in a billion different possible conformational states that this protein could have. You're saying, well, it has this one because that was (chuckles)
the only one it could take given its setting. - Well, yeah, I mean, currently humans are very good at that kind of first principles thinking, of stepping back. But I think AI is really good at, you know, collect a huge amount of data. And a huge amount of data
of observation of planets and figure out that Earth is not at the center of the universe, that there's actually a sun, we're orbiting the sun. But then you can, as a human being, ask, well, how did solar
systems come to be? What are the different
forces that are required to make this kind of pattern emerge? And then you start to
invent things like gravity. I mean, obviously. - (chuckles) Is it an invention? - I mixed up the ordering
of gravity wasn't considered as a thing that connects planets, but we are able to think
about those big picture things as human beings. AI is just very good
to infer simple models from a huge amount of data. And the question is
with biology, you know, we kinda go back and forth
how we solve biology. Listen, protein folding was thought to be impossible to solve. And there's a lot of
brilliant PhD students that worked one protein at a time, trying to figure out the structure, and the fact they was able to do that- - Oh, I'm not, I'm not knocking it at all, but I think that people have
been asking the wrong question. - But then as the people start to ask better and bigger questions, the AI kinda enters the chat and says, "I'll help you out with that." (chuckles) - [Nick] Can I give you another example from my own work?
- Sure. - The risk of getting a
disease as we get older, there are genetic aspects to it. You know, if you spend
your whole life overeating and smoking and whatever, that's a whole separate question. But there's a genetic side to the risk. And we know a few genes that increase your risk of certain things. And for probably 20 years now, people have been doing what's called GWAS, which is genome-wide association studies. So, you effectively scan the entire genome for any single nucleotide polymorphisms, which is to say a single
letter change in one place that has a higher association of being linked with a
particular disease or not. And you can up out with
thousands of these things across the genome. And if you add them all up and try and say, well, so do they add up to explain
the known genetic risk of this disease? And the known genetic risk
often comes from twin studies. And you can say that, you know, that if this twin gets epilepsy, there's a 40 or 50% risk
that the other twin, identical twin, will also get epilepsy. Therefore, the genetic
factor is about 50%. And so the gene similarities that you see should account
for 50% of that known risk. Very often it accounts
for less than a 1/10 of the known risk. And there's two possible explanations, and there's one which people tend to do, which is to say, ah, well, we don't have enough statistical power. Maybe there's a million, we've only found a thousand of them, but if we found the other million, they're weakly related, but there's a huge number of them, and so we'll account for that whole risk. Maybe there's, you know, maybe there's a billion of
them, (chuckles) for instance. So that's one way. The other way is to say, well, hang on a minute, you're missing a system here. That system is the mitochondrial DNA, which people tend to dismiss because it's small and it
doesn't change very much. But a few single letter changes
in that mitochondrial DNA, it controls some really basic processes, it controls not only all the
energy that we need to live and to move around and do everything we do but also biosynthesis, to make the new building blocks to, you know, to make new cells. And cancer cells very often kind of take over the mitochondria and rewire them so that
instead of using them for making energy, they're effectively
using them as precursors for the building blocks for biosynthesis. You need to make new amino acids, new nucleotides for DNA, you wanna make new lipids to
make your membranes and so on. So they kind of rewire metabolism. Now, the problem is that we've got all these interactions between mitochondrial DNA and the genes in the nucleus
that are overlooked completely because people throw away, literally throw away
the mitochondrial genes, and we can see in fruit flies that they interact and produce
big differences in risk. So, you can set, you can set AI onto this
question of exactly what, you know, how many of these
base changes there are, and that's just one possible solution that maybe there are a million of them, and it does account for the
greater part of the risk. Or the other one is they aren't, that it's just not there. Actually, the risk lies in something you weren't even looking at. And this is where human
intuition is very important. And there's this feeling that, well, I'm working on this and I think it's important and I'm bloody-minded about it, and in the end, some people are right, it turns out that it was important. Can you get AI to do that, to be bloody-minded? - And that, hang on a minute, you might be missing a
whole other system here that's much bigger. That's the moment of discovery
of scientific revolution. I'm giving up on saying
AI can't do something. I've said it enough times
about enough things, I think there's been a lot of progress. And instead, I'm excited
by the possibility of AI helping humans. But at the same time, just like I said, we seem to dismiss the power of humans. - [Nick] Yes, yes. - Like, we're so limited in so many ways that we kinda, in what we feel like dumb ways, like we're not strong, we're kinda, our attention, our memory is limited, our ability to focus on things is limited in our own perceptions of what limited is, but that actually there's
an incredible computer behind the whole thing that makes this whole system work. Our ability to interact
with the environment, to reason about the environment, there's magic there. And I'm hopeful that AI can
capture some of that same magic, but that magic is not gonna look like Deep Blue playing chess. - [Nick] No. - It's going to be more interesting, - But I don't think it's gonna look like pattern-finding either. I mean, that's essentially what you're telling me it
does very well at the moment, and my point is it works very well where you're looking
for the right pattern. But we are storytelling animals, and a hypothesis is a story, it's a testable story. But, you know, a new hypothesis
is a leap into the unknown and is a new story basically. And it says this leads to that, it's a causal set of storytelling. - It's also possible that the leap into the unknown has a pattern of its own. - [Nick] Yes, it is. Is there-
- And it's possible that it's learnable. - I'm sure it is. There's a nice book by Arthur Koestler on the nature of creativity, and he likens it to a joke where the punchline goes off in a completely unexpected direction, and says that this is the
basis of human creativity, that, you know, some creative switch of direction to an unexpected place
is similar to a joke. I'm not saying that's how it works, but it's a nice idea, and there must be some truth in it. And it's one of these... Most of the stories we tell
are probably the wrong story and probably going nowhere and probably not helpful, and we definitely don't do as well at seeing patterns in things. But some of the most
enjoyable human aspects is finding a new story that
goes to an unexpected place. And again, these are all aspects of what being human means to me. And maybe these are all things that AI figures out for itself or maybe they're just aspects, but I just have the feeling sometimes that the people who are
trying to understand what we are like, if we wish to craft an AI system which is somehow human-like, that we don't have a firm enough grasp of what humans really are like in terms of how we are built. - But we get a better,
better understanding of that, I agree with you completely. We try to build a thing, and then we go, hang on a minute. - [Nick] Yeah. - There's another system here, and that's actually the attempt to build AI that's human-like is getting us to a deeper
understanding of human beings. The funny thing is, I recently talked to Magnus Carlsen, widely considered to be
the greatest chess player of all time. And he talked about AlphaZero, which is a system from
DeepMind that plays chess. And he had a funny comment. He has a kinda dry sense of humor. But he was extremely impressed when he first saw AlphaZero play. And he said that it did a lot of things that could easily be
mistaken for creativity. (Nick laughs) So he, like, as a typical human, refused to give the
system sort of its due, because it came up with a lot of things that a lot of people are
extremely impressed by, not just the sheer calculation but the brilliance of play. So one of the things that it does in really interesting ways
is it sacrifices pieces. So in chess, that means you
basically take a few steps back in order to take a step forward. You give away pieces
for some future reward. And that, for us humans, is where art is in chess. You take big risks that for us humans, those risks are especially painful because you have a fog
(Nick chuckles) of uncertainty before you. So to take a risk now based on intuition of I think this is the right risk to take, but there's so many possibilities that that's where it takes guts, that's where art is, that's that danger. And then AlphaZero takes those same kind of risks and does them even greater degree, but of course it does it from where you could easily reduce down to a cold calculation over patterns. But boy, when you see the final result, it sure looks like the same kind of magic that we see in creativity, when we see creative
play on the chess board. But the chess board is very limited. And the question is, as we get better and better, can we do that same kind of creativity in mathematics, in programming? And then venturing biology, psychology, and expand into more and
more complex systems. - I used to go running when I was a boy. Fell running, which is to say
running up and down mountains. And I was never particularly great at it, but there were some people
who were amazingly fast, especially at running down. And I realized in trying to do this that there's only really two ways, there's three possible ways of doing it, and there's only two that work. Either you go extremely
slowly and carefully, and you figure out, okay, there's a stone, I'll put my foot on this stone, and then, oh, there's another, there's a muddy puddle I'm gonna avoid, and, you know, it's slow, it's laborious, you figure it out step by step. Or you can just go incredibly fast, and you don't think about it at all, the entire conscious
mind is shut out of it. And it's probably the same playing table tennis or something. There's something in the mind which is doing a whole lot
of subconscious calculations, and it's amazing, you can run at astonishing
speed down a hillside with no idea how you did it at all. And then you panic and you think, I'm gonna break my leg
if I keep doing this, I've gotta think about
where I'm gonna put my foot. So you slow down a bit and try to bring the conscious mind in, and then you do, you crash. You you cannot think consciously
while running downhill. And so it's amazing,
(Lex chuckles) it's amazing how many calculations
the mind is able to make. And now, the problem with
playing chess or something, if you're able to make all of those subconscious
kind of forward calculations about what is the likely
outcome of this move now in the way that we can by running down a hillside or something, you know, it's partly about
what we have adapted to do. It's partly about the reality
of the world that we're in. Running fast downhill is something that we better be bloody good at, otherwise we're gonna be eaten. Whereas trying to calculate
multiple, multiple moves into the future is not something we've ever been called on to do. And two or three, four moves into the future's quite
enough for most of us most of the time. - Yeah, yeah. So, yeah, just solving chess may not, we may not be as far
towards solving the problem of downhill running
(Nick chuckles) as we might think just
because we solve chess. Still, it is beautiful to see creativity, humans create machines that are able to create art and art on the chess
board and art otherwise. Who knows how far that takes us? So I mentioned Andrej Karpathy earlier. Him and I are big fans of yours. If you're taking votes, his suggestion was you
should write your next book on the Fermi paradox. (Nick chuckles) So let me ask you on
the topic of alien life, since we've been talking about life and we're kind of aliens. How many alien civilizations
are out there, do you think? - Well, the universe is very big, so some. But not as many as most
people would like to think, is my view, because the idea that
there is a trajectory going from simple cellular
life like bacteria all the way through to humans, seems to me there's some
big gaps along that way. The eukaryotic cell, the complex cell that we have, is the biggest of them, but also photosynthesis is another. Another interesting gap is a long gap from the origin of the eukaryotic cell to the first animals, that was about a billion years, maybe more than that. And a long delay in when
oxygen began to accumulate in the atmosphere. So from the first appearance of oxygen in the Great Oxidation Event to enough for animals to respire, it was close to 2 billion years. Why so long? Seems to be planetary factors, it seems to be geology as
much as in anything else, and we don't really
know what was going on. So the idea that there's a
kind of an inevitable march towards complexity and sentient life, I don't think is right. Not to say it's not gonna happen, but I think it's not gonna happen often. - So if you think of Earth, given the geological constraints and all that kind of stuff, do you have a sense that life, complex life, intelligent life, happened really quickly
on Earth, or really long? So, just to get a sense of, are you more sort of saying that it's very unlikely to get the kind of conditions
required to create humans, or is it even if you have the condition, it's just statistically difficult? - I think, I mean, the problem, the single great problem at
the center of all of that, to my mind, is the origin
of the eukaryotic cell, which happened once, and without eukaryotes, nothing else would've happened. And that is something that-
- Really? 'Cause you're saying it's super important, eukaryotes, but- - I'm saying, tantamount of saying that it is impossible to build something as complex as a human
being from bacterial cells. - Totally agree in some
deep fundamental way, but it's just, like, one
cell going inside another. Is that so difficult to get to work right, like, statistically?
- Well, again, it happened once, and if you think about, I'm in a minority view in this position, most biologists probably
wouldn't agree with me anyway. But if you think about the starting point, we've got a simple cell. It's an archaeal cell, we can be fairly sure about that. So it looks a lot like a bacterium but is in fact from this
other domain of life. So it looks a lot like a bacterial cell. That means it doesn't have anything, it doesn't have a nucleus, it doesn't really have
complex endomembrane. It has a little bit of stuff, but not that much. And it takes up an endosymbiont. So what happens next? And the answer is basically everything to do with complexity. To me, there's a beautiful paradox here. Plants and animals and fungi all have exactly the same type of cell, but they all have really
different ways of living. So a plant's cell is photosynthetic, they started out as algae
in the oceans, and so on. So think of algal blooms, single cell things. You know, the basic cell
structure that it's built from is exactly the same with a
couple of small differences, it's got chloroplast as well, it's got a vacuole, it's got a cell wall, but that's about it. Pretty much everything
else is exactly the same in a plant cell and an animal cell. And yet the ways of life
are completely different. So this cell structure did not evolve in response to different ways of life, different environments. I'm in the ocean doing photosynthesis, I'm on land running around
as part of an animal, I'm a fungus in a soil spinning
out long kind of shoots into whatever it may be, mycelium. So they all have the same
underlying cell structure, why? Almost certainly it was
driven by adaptation to the internal environment, to having these pesky endosymbionts that forced all kinds of
change on the host cell. Now, in one way, you could see
that as a really good thing because it may be that there's some inevitability
to this process, that as soon as you got endosymbionts, you're more or less bound
to go in that direction, or it could be that there's
a huge fluke about it and it's almost certain to go wrong in just about every case possible, that the conflict will
lead to effectively war, leading to death and extinction, and it simply doesn't work out. So maybe it happened millions of times and it went wrong every time, or maybe it only happened once, and it worked out because
it was inevitable. And actually we simply
do not know enough now to say which of those two
possibilities is true, but both of them are a bit grim. - But you're leaning towards we just got really lucky in that one leap. So, do you have a sense that
our galaxy, for example, has just maybe millions of planets with bacteria living on it? - I would expect billions, tens of billions of planets with bacteria living on
it practically, I would. I mean, there's probably what, 5 to 10 planets per star of which I would hope that at least one would have bacteria on. So I expect bacteria to be very common. I simply can't put a number otherwise, I mean, I expect it will happen elsewhere. It's not that I think we're living in a completely empty universe. - [Lex] That's so fascinating. - But I think that it's
not gonna happen inevitably and there's something, you know, that's not the only problem with complex life on Earth, I mentioned oxygen and
animals and so on as well. And even humans, we came along very late. You go back 5 million years, and, you know, would we be that impressed if we came across a
planet full of giraffes? I mean, you'd think, hey, there's life here, there's a nice planet to
colonize or something. We wouldn't think, oh, let's try and have a
conversation with this giraffe. - Yeah, I'm not sure what
exactly we would think. I'm not exactly sure what
makes humans so interesting from an alien perspective, or how they would notice. I'll talk to you about cities too, 'cause that's an interesting perspective of how to look at human civilization. But your sun's, I mean, of course you don't know, but it's an interesting world, it's an interesting galaxy, it's an interesting universe to live in, that's it's just like, every sun, like 90% of solar systems have bacteria in it. Like, imagine that world. And the galaxy maybe has just a handful, if not one intelligent civilization. That's a wild world. - It's a wild world.
- I didn't even even think about that world. There's a kinda thought that, like, one of the reasons
it would be so exciting to find life on Mars or Titan or whatever is, like, if it's life as elsewhere, then surely, statistically, that life, no matter how unlikely, eukaryotes, multi-cell organisms, sex, violence, what else is extremely difficult? I mean, photosynthesis, figuring out some machinery that involves the chemistry
in the environment to allow the building
up of complex organisms, surely that would arise. But man, I don't know how I would feel about just bacteria everywhere. - Well, it would be
depressing if it was true. I suppose depressing.
- All the wasted potential. I don't know what's more depressing, bacteria everywhere or nothing everywhere. - Yes, either of them are chilling. - [Lex] Yeah. - But whether it's chilling or not, I don't think should force us to change our view about
whether it's real or not. - Yes, yes.
- And what I'm saying may or may not be true. - So how would you feel if
we discovered life on Mars? - I'd be delighted.
- It sounds like you would be less
excited than some others, because you're like, well... - What I would be most
interested in is how similar to life on Earth it would be. It would actually turn into
quite a subtle problem, because the likelihood of life having gone to and fro between Mars and the Earth is quite, I wouldn't say high, but it's not low. It's quite feasible. And so if we found life on Mars and it had very similar genetic code but it was slightly different, most people would interpret
that immediately as evidence that there'd been transit
one way or the other and that it was a common origin of life on Mars or on the Earth, and it went one way or the other way. The other way to see
that question, though, would be to say, well, actually the whole beginnings of life lie in deterministic chemistry
and thermodynamics, starting with the most
likely abundant materials, CO2 and water, and a wet, rocky planet, and Mars was wet and
rocky at the beginning, and will, I won't say inevitably, but potentially almost inevitably come up with a genetic code which
is not very far away from the genetic code
that we already have. So, we see subtle differences
in the genetic code, what does it mean? It could be very difficult to interpret. - Is it possible, do you think, to tell the difference of
something that truly originated? - I think if the
stereochemistry was different. We have sugars, for example, that are the L form or the D form, and we have D-sugars and L-amino acids right
across all of life. But lipids, the bacteria have one stereo isomer, and the bacteria have the other, the opposite stereo isomer. So it's perfectly possible
to use one or the other one, and the same would
almost certainly go for, and I think George Church has been trying to make life based on the
opposite stereo isomer. So it's perfectly possible to do, and it will work. And if we were to find life on Mars that was using the opposite stereo isomer, that would be unequivocal evidence that life had started independently there. - So hopefully the life we find
will be on Titan and Europa or something like that, where it's less likely that we shared, and it's harsher conditions so there's gonna be weirder kinda life. - I wouldn't count on that because- - Water.
- If life started in deep sea hydrothermal vents here. - [Lex] It's so harsh conditions. - That's pretty harsh, yeah. So Titan is different. Europa is probably quite similar to Earth in the sense that we're
dealing with an ocean. It's an acidic ocean there, as the early Earth would've been. And it almost certainly
has hydrothermal systems. Same with Enceladus. We can tell that from these plumes coming from the surface through the ice, we know there's a liquid ocean and we can tell roughly
what the chemistry is. For Titan, we're dealing
with liquid methane and things like that, so that would really, if there really is life there, it would really have to
be very, very different to anything that we know on Earth. - So the hard leap, the hardest leap, the most important leap is
from prokaryotes to eukaryotes. What's the second, if we were ranking? You gave a lot of emphasis
on photosynthesis. - Yeah, and that would be
my second one, I think. But it is not so much, I mean, photosynthesis
is part of the problem. It's a difficult thing to do. Again, we know it happened once. We don't know why it happened once. But the fact that it was kind of taken on board completely by plants and algae
and so on as chloroplasts and did very well in completely
different environments and then on land and whatever else seems to suggest that there's
no problem with exploring, well, you know, you could
have a separate origin that explored this whole domain over there that the bacteria had never gone into. So that kind of says that the reason that it only happened once is probably because it's difficult, because the wiring is difficult. - [Lex] Yeah. - But then, it happened at
least 2.2 billion years ago, right before the GOE. Maybe as long as 3 billion years ago, when some people say there
are whiffs of oxygen, there's just kind of traces in the fossil in the geochemical record that say maybe there's
a bit of oxygen then, that's really disputed. Some people say it goes all the
way back 4 billion years ago and that the common
ancestor of life on Earth was photosynthetic. So immediately you've got, you know, groups of people who disagree over a 2-billion-year period of time about (chuckles) when it started. But let's take the latest
date when it's unequivocal, that's 2.2 billion years ago, through to around about the time of the Cambrian explosion, when oxygen levels definitely
got close to modern levels, which was around about
550 million years ago. So we've gone more than one
and a half billion years where the Earth was in stasis. Nothing much changed. It's known as the Boring Billion, in fact. Probably stuff was, that was when eukaryotes
arose somewhere in there. So this idea that the world
is constantly changing, that we're constantly evolving, that we're moving up some ramp, it's a very human idea. But in reality, there are, there are kind of tipping points to a new stable equilibrium, where the cells that are producing oxygen are precisely counterbalanced by the cells that are
consuming that oxygen, which is why it's 21% now and has been that way for
hundreds of millions of years. We have a very precise balance. You go through a tipping point, and you don't know where the
next stable state's gonna be, but it can be a long way from here. And so if we change the
world with global warming, there will be a tipping point. Question is where and when, and what's the next stable state? It may be uninhabitable to us. It'll be habitable to life for sure. But there may be something
like the Permian extinction, where 95% of species go extinct and there's a 5- to 10-million-year gap and then life recovers but without humans. - And the question, statistically, well, without humans, but statistically does
that ultimately lead to greater complexity, more interesting life, more intelligent life?
- Well, after the first appearance of oxygen with the GOE, there was a tipping point which led to a long-term stable state that was equivalent to
the Black Sea today, which is to say oxygenated
at the very surface and stagnant, sterile, not sterile, but sulfurous lower down. And that was stable certainly
around the continental margins for more than a billion years. It was not a state that led to progression in an obvious way. - Yeah, I mean, it's interesting to think about evolution, like, what leads to stable states and how often are evolutionary pressures
emergent from the environment? So, maybe other planets are able to create evolutionary pressures, chemical pressures, whatever, some kind of pressure that say, you're screwed unless you
get your shit together in the next like 10,000 years. Like, a lot of pressure.
- Yeah. - it seems like Earth, like, the Boring Billion might
be explained in two ways. One, it's super difficult to
take any kind of next step, and the second way it
could be explained is, there's no reason to take the next step. - No, I think there is no reason. But at the end of it, there was a snowball Earth. So there was a planetary
catastrophe on a huge scale where the ice, the sea was frozen at the equator, and that forced change, in one way or another. It's not long after that,
a hundred million years, perhaps after that, so not short time, but this is when we begin to see animals. There was a shift again, another tipping point that
led to catastrophic change that led to a takeoff then. We don't really know why, but one of the reasons why
that I discuss in the book is about sulfate being
washed into the oceans, which sounds incredibly parochial. But the issue is, I mean, what the data is showing, we can track roughly how oxygen was going into the atmosphere from carbon isotopes. So there's two main isotopes of carbon that we need to think about here, one is carbon-12, 99% of carbon is carbon-12, and then 1% of carbon is carbon-13, which is a stable isotope. And then there's carbon-14, which is a trivial, radioactive, it's trivial amount. So carbon-13 is 1%. And life and enzymes generally, you can think of carbon atoms as little balls bouncing around, ping pong balls bouncing around. Carbon-12 moves a little
bit faster than carbon-13 because it's lighter, and it's more likely
to encounter an enzyme. And so it's more likely to
be fixed into organic matter. And so organic matter's enriched, and this is just an observation, it's enriched in
carbon-12 by a few percent compared to carbon-13, relative to what you would
expect if it was just equal. And if you then bury organic matter as coal or oil or whatever it may be, then it's no longer oxidized. So some oxygen remains left
over in the atmosphere, and that's how oxygen
accumulates in the atmosphere. And you can work out historically how much oxygen there must
have been in the atmosphere by how much carbon was being buried. And you think, well,
how can we possibly know how much carbon was being buried? And the answer is, well, if you're burying carbon-12, all you're leaving behind is
more carbon-13 in the oceans, and that precipitates out as limestone. So you can look at
limestones over these ages and work out what's the carbon-13 signal. And that gives you kind of a feedback on the oxygen content. Right before the Cambrian explosion, there was what's called a negative isotope anomaly excursion, which is basically the carbon-13 goes down by a massive amount and then back up again
10 million years later. And what that seems to be saying is the amount of carbon-12 in the oceans was disappearing, which is to say it was being oxidized. And if it's being oxidized, it's consuming oxygen. So a big carbon-13 signal says the ratio of carbon-12 to carbon-13
is really going down, which means there's much more carbon-12 being taken out and being oxidized. Sorry, this is getting too complex, but. - Well, it's a good way to estimate the amount of oxygen. - Yeah, if you calculate
the amount of oxygen based on the assumption
that all this carbon-12 that's being taken out is
being oxidized by oxygen, the answer is, all the oxygen in the atmosphere gets stripped out, there is none left. And yet the rest of the
geological indicators say, no, there's oxygen in the atmosphere. So it's kind of a paradox. And the only way to explain this paradox, just on mass balance of how
much stuff is in the air, how much stuff is in
the oceans, and so on, is to assume that oxygen
was not the oxygen, it was sulfate. Sulfate was being washed into the oceans. It's used as an electron acceptor by sulfate-reducing bacteria just as we use oxygen
as an electron acceptor, so they pass their electrons
to sulfate instead of oxygen. - [Lex] Bacteria did. - Yeah, yeah. So these are bacteria. So they're oxidizing
carbon, organic carbon, with sulfate, passing the electrons onto sulfate. That reacts with iron to form ion pyrite, or fool's gold, sinks down to the bottom, gets buried out of the system. And this can account for the mass balance. So why does it matter? It matters because what it says
is there was a chance event. Tectonically, there was a lot
of sulfate sitting on land as some kind of mineral. So calcium sulfate minerals,
for example, are evaporitic. And because there happened to be some continental collisions, mountain building, the sulfate was pushed
up the side of a mountain and happened to get washed into the ocean. - Yeah, so I wonder how many happy accidents
like that are possible. - Yeah, statistically it's really hard. You know, maybe you can
rule that in statistically, but this is the course of life on Earth. Without all that sulfate being raised up, this Cambrian explosion almost certainly would not have happened. And then we wouldn't have had animals, and so on and so on. So, you know, it's... - This kind of explanation
of the Cambrian explosion. So, let me actually
say it in several ways. So, you know, folks who challenge the validity of the theory of evolution
will give us an example, now, I'm not well studied in this, but will give us an example
of the Cameron explosion as, like, this thing is weird. (chuckles) - [Nick] Oh, it is weird, yeah. - So, the question I would have is, what's the biggest mystery or gap in understanding about evolution? Is it the Cambrian explosion, and if so, how do we, what's our best understanding
of how to explain? First of all, what is it? In my understanding, in the short amount of time, maybe 10 million years, 100 million years, something like that, a huge number of animals, a variety, diversity of
animals were created. Anyway, there's like
five questions in there. - Yeah, yeah.
- Is that the biggest mystery? - No, I don't think it's a
particularly big mystery, really, anymore. I mean, there are still mysteries about why then. And I've just said sulfate being washed into the oceans is one. It needs oxygen, and oxygen levels rose around that time. So probably before that, they weren't high enough for animals. What we're seeing with
the Cambrian explosion is the beginning of predators
and prey relationships. We're seeing modern ecosystems and we're seeing arms races. And we're seeing, we're seeing the full creativity
of evolution unleashed. So, I talked about the Boring Billion. Nothing happens for, you know, one and a half, 1 billion years, 1.5 billion years. The assumption, and this is completely
wrong, this assumption, is then that, you know, evolution works really slowly, and that you need billions of years to affect some small change, and then another billion
years to do something else, and it's completely wrong. Evolution gets stuck in a stasis, and it stays that way
for tens of millions, hundreds of millions of years. And Stephen Jay Gould used to argue this, he called it punctuated equilibrium, but he was doing it to do with animals and to do with the last
500 million years or so, where it's much less obvious than if you think about the
entire planetary history. And then you realize that the first 2 billion
years was bacteria only. You have the origin of life, 2 billion years of just bacteria, oxygen and photosynthesis arising here, then you have a global catastrophe, snowball Earths and Great Oxidation Event, and then another billion
years of nothing happening, and then some period of upheavals, and then another snowball Earth, and then suddenly you see
the Cambrian explosion. This is long periods of stasis where the world is in a stable state and is not geared towards
increasing complexity, it's just everything is in balance. And only when you have
a catastrophic level, global-level problem
like a snowball Earth, it forces everything out of balance, and there's a tipping point, and you end up somewhere else. Now, the idea that
evolution is slow is wrong. It can be incredibly fast. And I mentioned earlier on, you can, you know, in theory, it would take half a million
years to invent an eye, for example, from a light-sensitive spot. It doesn't take long to convert, you know, one kind of tube into a tube with nubbles on it into a tube with arms on it, and then multiple arms, and then at one end is a head where it starts out as a swelling. You know, it's not
difficult intellectually to understand how these things can happen. It boggles the mind that
it can happen so quickly, but we're used to human timescales. And what we need to talk
about is generations of things that live for a year in the ocean, and then a million years
is a million generations, and the amount of change that you can do, you can affect in that
period of time is enormous. And we're dealing with
large populations of things where selection is sensitive
to pretty small changes. So, again, as soon as you throw in the competition of predators and prey and you're ramping up
the scale of evolution, it's not very surprising that it happens very quickly when the environment allows it to happen. So I don't think there's a big mystery, there's lots of details
that need to be filled in. I mean, the big mystery in
biology is consciousness. - The big mystery in
biology is consciousness. Well, intelligence is
kind of a mystery too. I mean, you said biology, not psychology. 'Cause from a biology perspective, it seems like intelligence and consciousness all are the same, like, weird, like, all the brain stuff. - I don't see intelligence as necessarily that difficult, I suppose. I mean, I see it as a form of computing, and I don't know much about
computing, so. (laughs) - Well, you don't know much
about consciousness either, so, (chuckles) I mean, I suppose... Oh, I see. I see, I see, I see, I see, that consciousness you do know a lot about as a human being. - No, no. I mean, I think I can
understand the wiring of a brain as a series of, in pretty much the same way
as a computer, in theory, in terms of the circuitry of it. The mystery to me is how this system gives rise to feelings, as we were talking about earlier on. - Yeah, I just, I think we oversimplify intelligence. I think the dance, the magic of reasoning is as interesting as the magic of feeling. - [Nick] Mm-hmm. - We tend to think of reasoning as, like, running a very simplistic algorithm. I think reasoning is the
interplay between memory, whatever the hell is going
on in the unconscious mind, all of that... - I'm not trying to diminish
it in any way at all. Obviously, it's extraordinarily,
exquisitely complex, but I don't see a logical
difficulty with how it works. - Yeah, no, I mean, I agree with you, but sometimes, yeah, there's a big cloak of mystery around consciousness. - I mean, let me compare it with classical versus quantum physics. You know, classical physics is logical and you can understand, (chuckles) the kind of language we're dealing with, it's almost at the human level, we're dealing with stars
and things that we can see. And when you get to quantum
mechanics and things, it's practically impossible
for the human mind to compute what just
happened there. (chuckles) - Yeah. I mean, that is the same. It's like, you understand mathematically the notes of a musical composition, that's intelligence. - Yes.
- But why it makes you feel a certain way. - [Nick] Mm. - That is much harder to understand. Yeah, that's really... But (chuckles) it was interesting framing that that's a mystery
at the core of biology. I wonder who solves consciousness. I tend to think
consciousness will be solved by the engineer, (laughs) meaning the person who builds it.
- You may well be right. - Who keeps trying to build the thing versus biology's such
a complicated system. I feel like it's, I feel like the building
blocks of consciousness from a biological perspective are like, that's, like, the final
creation of a human being, so you have to understand
the whole damn thing. You said electrical fields, but, like, electrical fields plus, plus. Everything, the whole shebang.
- Yes, yeah. I'm inclined to agree. I mean, my feeling is, from my meager knowledge
of the history of science, is that the biggest
breakthroughs usually come from a field that it was not related to. So, if anyone, you know, it's not gonna be a biologist
who solves consciousness, just because biologists are too embedded in the nature of the problem. And then nobody's gonna
believe you when you've done it because nobody's gonna be able to prove that this AI is in fact conscious and sad (chuckles) in any case any more than you can prove
that a dog is conscious and sad. So it tells you that it is, in good language, and you must believe it. But I think most people will accept, if faced with that, that that's what it is. All of this probability, though, of complex life. In one way, I think
why it matters is that, my expectation, I suppose, is that we will be, over the next hundred years or so, if we survive at all, that AI will increasingly dominate, and pretty much anything that we put out into space, looking for other, well, for the universe,
for what's out there, will be AI, won't be us. We won't be doing that, or when we do, it'll be on
a much more limited scale. And I suppose the same would apply to any alien civilization. So perhaps rather than looking
for signs of life out there, we should be looking for AI out there. But then we face the problem that I don't see how a planet is going to
give rise directly to AI. I can see how a planet
can give rise directly to organic life. And if the principles that govern the evolution
of life on Earth apply to other planets as well, and I think a lot of them would, then the likelihood of ending up with a human-like civilization capable of giving rise
to AI in the first place is massively limited. Once you've done it once, perhaps it takes over the universe, and maybe, (chuckles) maybe there's no issue. But it seems to me that the
two are necessarily linked, that you're not gonna
just turn a sterile planet into an AI life form without the intermediary
of the organics first. - So you have to run the
full evolutionary computation with the organics to create AI. - How does AI bootstrap
itself up without the aid, if you like, of an intelligent designer? - The origin of AI is going to have to be in the chemistry of a planet. So, but that's not a
limiting factor, right? So, I mean, let me ask the Fermi paradox question. Let's say we live in this incredibly dark and beautiful world of
just billions of planets with bacteria on it and very few intelligent civilizations, and yet there's a few out there. Why haven't we at scale
seen them visit us? What's your sense? Is it because they don't exist? Is it because-
- Well, don't exist in the right part of the
universe at the right time, that's the simplest answer for it. - Is that the one you
find the most compelling, or is there some other explanation? - I find that, no, it's not that I find it more compelling, it's that I find more probable, and I find all of them, I mean, there's a lot
of hand-waving in this, we just don't know. So, I'm trying to read out from what I know about life on Earth to what might happen somewhere else. It gives to my mind a
bit of a pessimistic view of bacteria everywhere and only occasional intelligent life. And, you know, running forward, humans, only once on Earth, and nothing else that
you would necessarily be any more excited about making contact with than you would be making
contact with them on Earth. So, I think the chances
are pretty limited, and the chances of us surviving
are pretty limited too. In the way we're going on at the moment, the likelihood of us not
making ourselves extinct within the next few hundred years, possibly within the next 50 or 100 years, seems quite small. I hope we can do better than that. So maybe the only thing that will survive from
humanity will be AI, and maybe AI, once it exists and once it's capable of
effectively copying itself and cutting humans out of the loop, then maybe that will
take over the universe. - I mean, there's a
kind of inherent sadness to the way you described that, but isn't that also potentially beautiful, that that's the next step of life? I suppose you, from your perspective, as long as it carries the
flame of consciousness somehow. - I think, yes, there can be some beauty to it being the next step of life. And I don't know if
consciousness matters or not from that point of view, to be honest with you. - [Lex] Yeah. - But there's some sadness, yes, probably, because I think it comes
down to the selfishness that we were talking about earlier on. I am an individual with a desire not to be
kind of displaced from life, I wanna stay alive, I want to (chuckles) be here. So I suppose the threat that
a lot of people would feel is that we will just be wiped out, that there will be potential conflict between AI and humans and that AI will win
because it's a lot smarter. - Boy, would that be
a sad state of affairs if consciousness is just
an intermediate stage between bacteria and AI. (Nick laughs)
Right? And so-
- Well, I would see bacteria as being potentially a
kind of primitive form of consciousness anyway.
- Right, so maybe- - The whole of life on Earth, to my mind- - It's conscious.
- It's capable of some form of feelings in response
to the environment. That's not to say it's
intelligent, though, it's got its own algorithms
for intelligence, but nothing comparable with us. I think it's beautiful what a sterile planet can come up with. It's astonishing that it's come up with all of this stuff
that we see around us, and that either we or whatever we produce is capable of destroying all of that. It is is a sad thought, but it's also, it's hugely pessimistic. I'd like to think that
we're capable of giving rise to something which is at least as good, if not better than us as AI. - Yeah, I have that same, I have that same optimism, especially a thing that
is able to propagate throughout the universe more
efficiently than humans can. Or extensions of humans, some merger with AI and humans, whether that comes from
bioengineering of the human body to extend its life somehow, to carry that flame of
consciousness and that personality and the beautiful tension
that's within all of us, carry that through to multiple planets, to multiple solar systems all
out there in the universe. I mean, that's a beautiful vision. Whether AI can do that or
bioengineered humans can, that's an exciting possibility, and especially meeting
other alien civilizations in that same kind of way. Do you think aliens have consciousness? - If they're organic, yes.
- So organic, connected to consciousness. - I mean, I think any system which is gonna bootstrap itself
up from planetary origins, I mean, let me finish this, and then I'll come on
towards something else, but from planetary origins is going to face similar constraints, and those constraints
are going to be addressed in similar basic engineering ways. And I think it will be cellular, and I think it will
have electrical charges, and I think it will have to be selected in populations over time, and all these things will tend to give rise to the same processes as the simplest fix to
a difficult problem. So I would expect it to be conscious, yes, and I would expect it to
resemble life on Earth in many ways. When I was about, I guess, 15 or 16, I remember reading a book by Fred Hoyle called "The Black Cloud," which, I was a budding
biologist at the time, and this was the first time
I'd come across someone really challenging the
heart of biology and saying, you are far too parochial, you know, you're thinking
about life as carbon-based. Here's a life form which is kind of dust, interstellar dust on a solar system scale. And, you know, it's a novel, but I felt enormously
challenged by that novel because it hadn't occurred to me how limited my thinking was, how narrow-minded I was being. And he was a great physicist with a completely different conception of what life could be. And since then, I've seen
him attacked in various ways. And I'm kind of reluctant to say the attacks make more sense to me than the original story, which is to say, even in terms of information processing, if you're on that scale and there's a limit to the speed of light, how quickly can something think if you're needing to broadcast across the solar system? It is going to be slow. It's not gonna hold a
conversation with you on the kind of timelines that
Fred Hoyle was imagining, or at least not by any
easy way of doing it, assuming that speed of light is a limit. And then, again, you really can't, this is something Richard
Dawkins argued long ago, and I do think he's right, there is no other way to generate this level of
complexity than natural selection. Nothing else can do it. You need populations, and you need selection in populations and kind of an isolated interstellar cloud. Again, there's unlimited time or maybe there's no
problems with distance, but you need to have a certain frequency of generational time to generate a serious level of complexity. And I just have a feeling
it's never gonna work. - Well, as far as we know, so natural selection, evolution, is really powerful tool here on Earth, but there could be other mechanisms. So whenever, I don't
know if you're familiar with cellular automata, but complex systems that
have really simple components and seemingly move based on simple rules when they're taken as a whole, really interesting complexity emerges. I don't know what the
pressures on that are. It's not really selection, but interesting complexity
seems to emerge. And that's not well understood exactly why that complexity emerges.
- I think there's a difference between complexity and evolution. So, some of the work we're
doing on the origin of life is thinking about how does, well, how do genes arise? How does information arise in biology? And thinking about it
from the point of view of reacting CO2 with
hydrogen, what do you get? Well, what you're gonna
get is carboxylic acids, then amino acids. It's quite hard to make nucleotides. And it's possible to make them, and it's been done, and it's been done following
this pathway as well. But you make trace amounts. And so the next question, assuming that this is the right
way of seeing the question, which maybe it's just not, but let's assume it is, is, well, how do you reliably
make more nucleotides then? How do you become more complex and better at becoming a
nucleotide-generating machine? And the answer is, well, you need positive feedback loops, some form of autocatalysis. So, that can work, and we know it happens in biology. If this nucleotide, for example, catalyzes CO2 fixation, then you're going to
increase the rate of flux through the whole system, and you're going to effectively
steepen the driving force to make more nucleotides. And this can be inherited because there are forms
of membrane heredity that you can have, and there are... Effectively, you can, if a cell divides in two and it's got a lot of stuff inside it and that stuff is basically
bound as a network which is capable of regenerating itself, then it will inevitably regenerate itself. And so you can develop greater complexity. But everything that I've said depends on the underlying rules of thermodynamics, there is no evolvability about that. It's simply an inevitable
outcome of your starting point, assuming that you're able to increase the driving
force through the system. You will generate more of the same, you'll expand on what you can do, but you'll never get
anything different than that. And it's only when you
introduce information into that as a gene, as a kind of small stretch of RNA, which can be random stretch, then you get real evolvability, then you get biology as we know it. But you also have selection as we know it. - Yeah, I mean, I don't know how to
think about information. That's the kinda memory of the system. So it's not, yeah, at the local level, it's propagation of copying
yourself and changing and improving your adaptability
to the environment. But if you look at Earth as a whole, it has a kind of memory, that's the key feature of it. - [Nick] In what way? - It remembers the stuff
it tries. (chuckles) Like, if you were to describe Earth, I think evolution is something that we experience as
individual organisms. That's how the individual
organisms interact with each other. There's a natural selection. But when you look at Earth as
an organism in its entirety, how would you describe it? I mean-
- Well, not as an organism. I mean, the idea of Gaia is lovely. And James Lovelock originally put Gaia out as an organism that had somehow evolved. And he was immediately
attacked by lots of people. And he's not wrong, but he backpedaled somewhat because that was more of a
poetic vision than the science. The science is now called
Earth systems science, and it's really about how does the world kind of regulate itself so it remains within the limits which are hospitable to life, and it does it amazingly well. And it is working at a planetary level of kind of integration, of regulation. But it's not evolving
by natural selection, and it can't because
there's only one of it. And so it can change over time, but it's not evolving. All the evolution is happening
in the parts of the system. - Yeah, but it's a
self-sustaining organism. What do you mean?
- No, it's sustained by the sun. (chuckles) - Right, so, I mean, so you don't think it's
possible to see Earth as its own organism? - I think it's poetic and beautiful, and I often refer to the
Earth as a living planet, but it's not, in biological terms, an organism, no. - If aliens were to visit Earth, what would they notice? What would be the basic unit
of life they would notice? - Trees, probably, I mean, it's green, it's green and blue, I think that's the first
thing you'd notice, is it stands out from space as being different to
any of the other planets. - So would notice the trees at first, 'cause the green.
- Well, I would. I'd notice the green, yes. - Yeah. And then probably notice, figure out the photosynthesis, and then- - Probably notice cities
second, I suspect. Maybe first.
- Yeah. - So let me actually-
- If they arrived at night, they'd notice cities first, that's for sure.
(Lex laughs) - It depends, depends the time. You write quite beautifully
in "Transformers," once again. I think you opened the book in this way, I don't remember. "From space," describing Earth. It's such an interesting
idea of what Earth is. You also, I mean, "Hitchhiker's Guide"
summarizing it as harmless, or mostly harmless, which is a beautifully poetic thing. You open "Transformers" with, "From space it looks grey and crystalline, obliterating the blue-green
colours of the living Earth. It is criss-crossed by irregular patterns and convergence striations. There's a central amorous density, where these scratches seem lighter. This 'growth' does not look alive, although it has extended
out along some lines, and there is something grasping and parasitic about it. Across the globe there
are thousands of them, varying in shape and detail, but all of them grey, angular, inorganic, spreading. Yet at night they light up, glowing up the dark sky, suddenly beautiful. Perhaps these cankers on the landscape are in some sense living - there's a controlled flow of energy, there must be information
and some form of metabolism; some turnover of materials. Are they alive? No, of course not; they are cities." So is there some sense that
cities are living beings? You think aliens would think
of them as living beings? - Well, it'd be easy to see it that way, wouldn't it? - It wakes up at night. They wake up at night.
(Nick chuckles) - Strictly nocturnal, yes.
(Lex chuckles) I imagine that any aliens that are smart enough to
get here would understand that they're not living beings. My reason for saying that is that we tend to think of biology
in terms of information and forget about the cells. And I was trying to draw a comparison between the cell as a city and the energy flow through the city and the energy flow through cells and the turnover of materials. And an interesting thing about cities is that they're not really
exactly governed by anybody. There are regulations and
systems and whatever else, but it's pretty loose. They have their own life, their own way of developing over time. And in that sense, they're quite biological. There was a plan after
the Great Fire of London. Christopher Wren was making plans, not only for St Paul's Cathedral, but also to rebuild in large
Parisian-type boulevards, a large part of the area of
Central London that was burnt. And it never happened because they didn't have
enough money, I think. But it's interesting what was in the plan. There were all these boulevards, but there were no pubs and no coffee houses
or anything like that. And the reality was London
just kind of grew up in a set of jumbled streets. And it was the coffee houses and the pubs where all the business of the
city of London was being done, and that was where the
real life of the city was, and no one had planned it, the whole thing was unplanned and works much better that way. And in that sense, the cell
is completely unplanned, it's not controlled by
the genes in the nucleus in the way that we might
like to think that it is, but it's this kind of evolved entity that has the same kind of flux, the same animation, the same life. So I think it's a beautiful analogy, but I wouldn't get too
stuck with it as a metaphor. - See, I disagree with you. I disagree with you. I think you are so steeped.
(Nick chuckles) And actually the entirety of science, the history of science is steeped in a biological framework of
thinking about what is life. And not just biological, it's very human-centric too. That the human organism
is the epitome of life on Earth. I don't know, I think there is some
deep, fundamental way in which a city is a living being in the same way that a individual human- - But it doesn't give
rise to an offspring city. So, I mean, it's not, it doesn't work by natural selection, it works by, if anything, memes, it works by. - Yeah, but isn't it-
- It's kind of copying itself conceptually as a mode of being. - So, I mean, maybe memes, maybe ideas are the organisms that are really essential
to life on Earth. Maybe it's much more important about the collective
aspect of human nature, the collective intelligence than the individual intelligence. Maybe the collective
humanity is the organism, and the thing that defines
the collective intelligence of humanity is the ideas. And maybe the way that
manifests itself is cities, maybe, or societies, or geographically constrained societies or nations and all that kinda stuff. I mean, from an alien perspective, it's possible that that is the
more deeply noticeable thing, not from a place of ignorance.
- Yes, but what's noticeable doesn't tell you how it works. I mean, I don't have any problem with what you're saying, really, except that it's not
possible without the humans. You know, we went from a
hunter-gatherer-type economy, if you like, without cities through to cities. And as soon as we get into human evolution and culture and society and so on, then yes, there are
other forms of evolution, other forms of change. But cities don't directly
propagate themselves, they propagate themselves
through human societies, and human societies only exist because humans as individuals
propagate themselves. So there's kind of a, there is a hierarchy there. And without the humans in the first place, none of the rest of it exists. - So to you, life is primarily
defined by the basic unit on which evolution can operate on Earth.
- I think it's a really important thing, yes. - Yeah. And we don't know, we don't have any other
better ideas than evolution for how to create life.
- I never came across a better idea than evolution.
(Lex chuckles) I mean, maybe I'm just
ignorant and I don't know. And there's, you know, you mentioned automata and so on, and I don't think specifically about that, but I have thought about it in terms of selective
units of the origin of life and the difference between
evolvability and complexity or just increasing complexity but within very narrowly defined limits. The great thing about
genes and about selection is it just knocks down all those limits, it gives you a world of
information in the end which is limited only by
the biophysical reality of what kind of an organism you are, what kind of a planet
you live on, and so on. And cities and all these
other forms that look alive and could be described as alive, because they can't propagate themselves, can only exist as the product of something that did propagate itself. - Yeah. I mean, there's a deeply compelling truth to that kind of way of looking at things, but I just hope that we
don't miss the giant cloud (Nick chuckles) among us. - I kind of hope that I'm
wrong about a lot of this, because I can't say that my worldview is
particularly uplifting. But in some sense, it doesn't matter if
it's uplifting or not. Science is about what's reality, what's out there, why is it this way? And I think there's beauty in that too. - There's beauty in darkness.
(Nick chuckles) You write about life and death sort of at the biological level, does the question of suicide, why live, does the question of why the human mind is
capable of depression, are you able to introspect that from a place of biology, of why our minds, why we humans can go to such dark places? Why can we commit suicide? Why can we go, you know, suffer, suffer, period, but also suffer from a
feeling of meaninglessness, of going to a dark place
that depression can take you? Is this a feature of life, or is it a bug? - Mm, I don't know. I mean, if it's a feature of life, then I suppose it would have to be true of other organisms as well. And I don't know, we were talking about dogs earlier on, and they can certainly
be very sad and upset and may mooch for days after their owner died
or something like that. So I suspect, in some sense, it's a feature of biology. It's probably a feature of mortality. It's probably... (sighs) But beyond all of that, I mean, I guess there's two
ways you could come at it. One of them would be to say, well, you can effectively do the math and come to the conclusion
that it's all pointless and that there's really no point in me being here any longer. And maybe that's true in the
greater scheme of things. You can justify yourself
in terms of society, but society will be gone
soon enough as well, and you end up with a very
bleak place just by logic. - In some sense, it's surprising that we can find any meaning at all. - Well, maybe this is where
consciousness comes in, that we have transient joy. But with transient joy, we have transient misery as well. And sometimes, with everything in biology, getting the regulation right
is practically impossible. You will always have a bell-shaped curve where some people unfortunately
are at the joy end and some people are at the misery end. And, you know, that's
the way brains are wired, and I doubt there's ever
an escape from that. It's the same with sex and
everything else as well, we're dealing with, you know, you can't regulate it, so it's anything goes, it's all part of biology. - Amen to that.
(Nick chuckles) Let me, on writing. In your book "Power, Sex, Suicide." First of all, can I just read off the books you've written?
(Nick chuckles) If there's any better titles
and topics to be covered, I don't know what they are. It makes me look forward to whatever you're going to write next, I hope there's things you write next. So first you wrote "Oxygen: The Molecule
that Made the World," as we've talked about this
idea of the role of oxygen in life on Earth. Then, wait for it, "Power, Sex, Suicide: Mitochondria
and the Meaning of Life." Then, "Life Ascending: The Ten Great
Inventions of Evolution." "The Vital Question," the first book I've read of yours, "The Vital Question: Why
is Life the Way it is?" And the new book "Transformer: The Deep
Chemistry of Life and Death." In "Power, Sex, Suicide," you write about writing, or about a lot of things, but I have a question about writing. You write, "In the Hitchhiker's Guide to the Galaxy, Ford Prefect spends 15 years
researching his revision to the Guide's entry on the Earth, which originally read 'Harmless.'" By the way, I would also, as a side question, would like to ask you what would be your
summary of what Earth is. (Nick chuckles)
But, you write, "His long essay on the
subject is edited down by the Guide to read 'Mostly harmless.' I suspect that too many new
editions suffer a similar fate, if not through absurd editing decisions, at least through a lack of
meaningful change in content. As it happens, nearly 15 years have passed since the 1st edition of Power,
Sex, Suicide was published, and I am resisting the temptation to make any lame revisions. Some say that even
Darwin lessened the power of his arguments in the Origin of Species through his multiple revisions, in which he dealt with criticisms and sometimes shifted his
views in the wrong direction. I prefer my original to speak for itself, even if it turns out to be wrong." Let me ask the question about writing, both your students in the academic setting but also writing some of
the most brilliant writings on science and humanity I've ever read. What's the process of writing? How do you advise other humans? If you were to talk to young Darwin or the young you
(Nick chuckles) and just young anybody and give advice about how to write and how to write well
about these big topics, what would you say? - I mean, I suppose
there's a couple of points. One of them is, what's the story? What do I wanna know? What do I wanna convey? Why does it matter to anybody? And very often, the most, the biggest, most interesting questions, the childlike questions are the one that actually
everybody wants to ask but don't quite do it in
case they look stupid. And one of the nice things
about being in science is the longer you're in, the more you realize it. Everybody doesn't know the
answer to these questions, and it's not so stupid
to ask them after all. - [Lex] Yes. - So, trying to ask the questions that I would've been asking
myself at the age of 15, 16, when I was really hungry
to know about the world and didn't know very much about it and wanted to go to the
edge of what we know, but be helped to get there. I don't wanna be, you know, too much terminology, and so I want someone to keep a clean eye on what the question is. Beyond that, I've wondered a lot about, who am I writing for? And that was, in the end, the only answer I had was myself, at the age of 15 or 16. Because even if you're, you know, you just don't know who's reading it but also where are they reading it. Are they reading it in the bath or in bed or on the metro, or are they listening to an audio book? Do you wanna have, you know, a recapitulation every few pages 'cause you read three pages at a time, or are you really irritated by that? You know, you're going to get criticism from people who are irritated
by what you're doing, and you don't know who they are or what you're gonna do
that's gonna irritate people, and in the end, all you can do is just try and please
yourself. (chuckles) - Yeah.
- And that means, well, what are these big, fun, fascinating and big questions, and what do we know about it? And can I convey that? And I kind of learnt in trying to write, first of all, say what we know. And I was shocked in the
first couple of books how often I came up quickly against all the stuff we don't know. And if you're trying to, I've realized later on in
supervising various physicists and mathematicians who are PhD students, and, you know, their maths
is way beyond what I can do. But the process of trying to work out, what are we actually gonna model here, what's going into this equation, is a very similar one to writing, what am I gonna put on a page? What's the simplest possible
way I can encapsulate this idea so that I now have it as a unit that I can kind of see how it interacts with the other units? And you realize that, well, if this is like that, and this is like this, then that can't be true. (chuckles) So you end up navigating your own path through this landscape, and that can be thrilling 'cause you don't know where it's going. And I'd like to think that that's one of the reasons my
books have worked for people, because this sense of a
thrilling adventure ride, I don't know where it's
going either. (chuckles) - So finding the simplest possible way to explain the things we know and the simplest possible way to explain the things we don't know, and the tension between those two. And that's where the story emerges. What about the edit? Do you find yourself, to the point of this, you know, editing down to mostly harmless?
- Yeah. - To arrive at simplicity, do you find the edit is productive, or does it destroy the magic
that was originally there? - No, I usually find, I think I'm perhaps a better
editor than I am a writer. I write and rewrite and
rewrite and rewrite. - So you put a bunch of
crap on the page first, and then see where, through the edit, where it take you?
- Well, yeah. But then there's the professional editors who come along as well. And, I mean, in "Transformer," the editor came back to me, well, after I'd sent, you know, two months after I sent the first edition, he'd read the whole thing and he said, "The first two chapters
present a formidable hurdle to the general reader. Go and do something about it." - Yes.
- And it was the last thing I really wanted to hear.
- Well, your editor sounds very eloquent in speech. - Yeah, well, this was an email, but I thought about it, and, you know, the bottom line is, he was right. And so I put the whole thing
aside for about two months. Spent the summer, this would've been, I guess last summer, and then turned to it with full attention in about September or something and rewrote those chapters
almost from scratch. I kept some of the material, but it took me a long time to process it, to work out what needs to change, where does it need to change, I wasn't writing in this time, how am I going to tell this story better so it's more accessible and interesting? And in the end, I think it worked. It's still difficult, it's still biochemistry, but it has, he ended up saying, "Now it's got a barreling energy to it." And I was, you know, because he'd been, 'cause he'd told me the
truth the first time, I decided to believe that
he was telling me the truth the second time as well and was delighted. - Could you give advice to
young people in general, folks in high school, folks in college, how to take on some of the
big questions you've taken on. Now, you've done that
in the space of biology and expanded out. How can they have a career they can be proud of or have a life they can be proud of? - Gosh, that's a big question. (both chuckling) - I'm sure you've gathered some wisdom that you can impart-
- Yeah. - Onto the young populous.
- So the only advice that I actually ever
give to my students is, follow what you're interested in. Because they're often worried that if they make this decision now and do this course instead of that course, then they're gonna restrict
their career opportunities. There isn't a career path in science. It's not, I mean, there is, but there isn't. There's a lot of competition, there's a lot of death symbolically. So who survives? The people who survive are the people who care enough to still do it. And they're very often the people who don't worry too much about the future and are able to live in the present. 'Cause if you, you know, you do a PhD, you've competed hard to get onto the PhD, then you have to compete
hard to get a post-doc job. And you have, you know, the next bond may be on another continent, and it's only two years anyway. And so, and there's no guarantee you're gonna get a faculty
position at the end of it. So-
- And there's always a next step to compete if you get a faculty position.
- Yeah. - You get a tenure, and with tenure, you go full professor, full professor, then you go to some kind of, whatever
the discipline is, there's an award. If you're in physics, you're always competing
for the Nobel Prize, there's different awards.
- Yeah, yeah, yeah. - And then eventually
you're all competing to, I mean, there's always a competition. - So there is no happiness. Happiness does not lie there.
- If you're looking into the future, yes. - And if what you're
caring about is a career, then it's probably not the one for you. If, though, you can put that aside. And, you know, I've also worked in industry for a brief period, and I was made redundant twice, so I know that-
- (laughs) Redundant. - That, you know, there's no guarantee-
- Evolution. - That you got a career that way either. - [Lex] Yes. - So, live in the moment, and try and enjoy what you're doing. And that means really go to, go to the themes that
you're most interested in and try and follow them
as well as you can. And that tends to pay
back in surprising ways. I don't know if you've found this as well, but I found that people
will help you often if they see some light shining in the eye and you're excited about their subject and, you know, just want to talk about it. And they know that their friend in California's got a job coming up, they'll say, "Go for this,
this guy's all right." You know, they'll use the network to help you out if you really care. And you're not gonna have a
job two years down the line, but if what you really care
about is what you're doing now, then it doesn't matter if you have a job in two years time or not. It'll work itself out if you've got the light in your eye. And so that's the only advice I can give. And most people probably
drop out through that system because the fight is just
not worth it for them. - Yeah, when you have
the light in your eye, when you have the
excitement for the thing, what happens is you start
to surround yourself with others that are
interested in that same thing that also have the light, if you really are rigorous about this, 'cause I think it does take, it takes effort to make- - Oh, you've gotta be obsessive. But if you're doing what
you really love doing, then it's not work anymore, it's what you do. - Yeah, but I also mean
the surrounding yourself with other people that are
obsessed about the same thing, 'cause depending on-
- Oh, that takes some work as well, yes, and luck.
- You know, finding the right, yeah, finding the right mentors, the collaborators. Because I think one of the
problem with the PhD process is people are not careful enough in picking their mentors. Those are people, mentors and colleagues and so on, those are people gonna define
the direction of your life, how much you love a thing. I mean, the power of just, like, the few little conversations
you have in the hallway, it's incredible. So you have to be a little
bit careful in that. Sometimes you just get
randomly almost assigned. Really pursue, I suppose, the subject as much as you pursue the
people that do that subject. So, like, both, the whole dance of it. - [Nick] They kind of go together, really. - Yeah, they do, they really do. But take that part seriously, and probably in the way
you're describing it, careful how you define success, 'cause-
- You'll never find happiness in success, I don't think. There's a lovely quote from
Robert Louis Stevenson, I think, who said, "Nothing in life is so
disenchanting as attainment." (Lex laughs) - Yeah, so, I mean, in some sense, the true
definition of success is getting to do today what you really enjoy doing, just what fills you with joy, and that's ultimately success. Success isn't the thing
beyond the horizon, the big trophy, the financial. - I think it's as close as
we can get to happiness. That's not to say you're
full of joy all the time, but it's as close as we can get to a sustained human happiness, is by getting some fulfillment from what you're doing on a daily basis. And if what you're looking for is the world giving you
the stamp of approval with a Nobel Prize or a fellowship or whatever it is, then... You know, I've known people like this, who they're eaten away by the anger, the kind of caustic resentment that they've not been awarded
this prize that they deserve. - And the other way, if you put too much value
into those kinds of prizes and you win them, I've gotten the chance
to see that it also, the more, quote, unquote, successful you are in that sense, the more you run the danger of growing egos so big that you don't get to actually enjoy the beauty of this life. You start to believe that
you've figured it all out as opposed to, I think, what ultimately the most fun thing is, is being curious about
everything around you, being constantly surprised, and these little moments of discovery, of enjoying beauty in small and big ways all around you. And I think the bigger your ego grows, the more you start to
take yourself seriously, the less you're able to enjoy that. - Oh, man, to that, I couldn't agree more. - So, you know, the summary from harmless
to mostly harmless in "Hitchhiker's Guide to the Galaxy," how would you try to summarize Earth? And, you know, if you were given, if you had to summarize the whole thing in a couple of sentences and maybe throwing
meaning of life in there, like, why?
(Nick chuckles) Why? Maybe, is that a defining
thing about humans, that we care about the
meaning of the whole thing? I wonder if that should be part of it, these creatures seem to
be very lost (chuckles) and searching.
- Yes, they're always asking why. I mean, that's my
defining question, is why? People made a joke, I have a small scar on my forehead from a climbing accident years ago, and the guy I was climbing
with had dislodged a rock, and he'd shouted something. He shouted, "Below," I think, meaning that the rock was coming down. And I hadn't caught what he said, so I looked up and it smashed
straight on my forehead. And everybody around me
took the piss, saying, "He looked up to ask why." (both laughing) - Yeah, but that's a human imperative. That's part of what it means to be human. - Yeah.
- Look up to the sky and ask why. (laughs) And ask why. - So your question, define the Earth. I'm not sure I can do that. I mean, the first word that
comes to mind is living. I wouldn't like to say mostly living, but perhaps. (laughs) - Mostly living?
- Yeah. - Well, it's interesting, 'cause, like, if you were to write "The Hitchhiker's Guide to the Galaxy," I suppose, say our idea that we talked about the bacteria is the most prominent form of life throughout the galaxy and the universe, I suppose that Earth
would be kind of unique and would require-
- So there's abundance, in that case. - [Lex] Yeah. - It's profligate, it's rich, it's enormously living. (chuckles) - So how would you describe
that it's not bacteria? It's... - [Nick] Eukaryotic. - (laughs) Yeah. Eukaryotic, yeah.
- Well, I mean, that's the technical term, but it is, basically is. (Lex chuckles) - [Lex] Yeah, and then photosynthesis.
- How would I describe that? I've actually really
struggled with that term, because the word, I mean, there's few words
quite as good as eukaryotic to put everybody off immediately. (chuckles) You start
using words like that, and they'll leave the room. Krebs cycle is another one that gets people to leave the room. (both chuckling) But-
- That's an interesting- - But so I've tried to think, is there another word for
eukaryotic that I can use? And really the only word that I've been able to use is complex. Complex cells, complex life, and so on. And that word, it serves one immediate purpose, which is to convey an impression, but then it means so
many different things, just everybody actually
is lost immediately. And so it's kind of. (chuckles) - Well that's noticeable, from the perspective of other planets, that is a noticeable phase
transition of complexity, is the eukaryotic. What about the harmless
and the mostly harmless? Is that kind of... - Probably accurate on a
universal kind of scale. I don't think that
humanity is in any danger of disturbing the universe at the moment. - At the moment, which is why the mostly. We don't know, depends what Elon is up to. Depends how many rockets.
(Nick chuckles) I think-
- Yes, it'll be still, even then, a while, I think, before we disturb
the fabric of time and space. - Was the aforementioned Andrej Karpathy, I think he summarized Earth as a system where you hammer it
with a bunch of photons, the input is like photons, and the output is rockets. (Nick laughs) So if you just... - Well, that's a hell of a lot of photons before it was a rocket launch. - Yeah, but, like,
(Nick laughs) you know, maybe in the
span of the universe, it's not that much time. And I do wonder, you
know, what the future is, whether we're just in the
early beginnings of this Earth, which is important when
you try to summarize it, or we're at the end, where humans have finally
gained the ability to destroy the entirety
of this beautiful project we got going on, now with nuclear weapons, with engineered viruses, with all those kinds of things. - Or just inadvertently
through global warming and pollution and so on. We're quite capable. I mean, we just need to pass a tipping point.
- Quickly or slowly? I mean, I think we're more likely to do it inadvertently
than through a nuclear war, which could happen at any time. But my fear is we just don't know where
the tipping points are, and we will, we kind of think we're smart enough to fix the problem quickly
if we really need to, I think that's the overriding assumption, that we're all right for now. Maybe in 20 years time, it's gonna be a calamitous problem, and then we'll really need to put some serious mental
power into fixing it without seriously worrying that
perhaps that it's too late. And that however brilliant we are, we missed the boat. - And just walk off the cliff. I don't know, I have optimism in humans being clever descendants of apes.
- Oh, I have no doubt that we can fix the problem, but it's an urgent problem, and we need to fix it pretty sharpish. And I do have doubts about whether politically we are capable of coming together enough to, not just in any one country but around the planet. I mean, I know we can do it, but do we have the will? Do we have the vision to accomplish it? - That's what makes this whole ride fun. We don't know.
(Nick laughs) Not only do we not know if we can handle the crises before us, we don't even know all the crises that are gonna be before us in the next 20 years. The ones I think that will
most likely challenge us in the 21st century are the
ones we don't even expect. People didn't expect World War II at the end of World War I. You certainly-
- Well, some folks did, but yeah, not at the end of World War I, but by the late 1920s, I think people were
beginning to worry about it. - Yeah, no, there's always people worrying about everything.
- Yeah. - So, if you focus on the thing that- - [Nick] People worry about, yes. - 'Cause there's a million
things people worry about, and 99.99999% of them don't come to be. Of course the people that
turn out to be right, they'll say, "I knew all along," but that's not, you know, that's not an accurate way of knowing what you could have predicted. I think, rationally speaking, you can worry about it, but nobody thought you could
have another world war. The war to end all wars, why would you have another war? And the idea of nuclear weapons, just technologically, is a very difficult thing to anticipate. To create a weapon that just
jumps orders of magnitude and destructive capability. And of course we can intuit all the things like engineered viruses, nanobots, artificial intelligence, yes, all the different
complicated global effects of global warming. So how that changes the
allocation of resources, the flow of energy, the tension between countries, the military conflict between countries, the reallocation of power. Then looking at the role of
China in this whole thing, with Russia and growing
influence of Africa, and the weird dynamics of Europe, and then America falling apart through the political division fueled by recommender systems
through Twitter and Facebook. The whole beautiful mess is just fun. And I think there's a lot
(Nick laughs) of incredible engineers, incredible scientists,
incredible human beings, that while everyone is
bickering and so on online for the fun of it on the weekends, they're actually trying
to build solutions. And those are the people that will create something beautiful. You know, that's the process of evolution. It all started with a Chuck
Norris single-cell organism that went out from the vents and was the parent to all of us. And for that guy or lady, or both, I guess, (chuckles) is a big thank you, and I can't wait to what happens next. And I'm glad there's
incredible humans writing and studying it like you are, Nick. It's a huge honor that
you would talk to me. - [Nick] That was fantastic. - This was really amazing, I can't wait to read what you write next. Thank you for existing,
(Nick chuckles) (chuckles) and thank
you for talking today. - Thank you. - Thanks for listening to this
conversation with Nick Lane. To support this podcast, please check out our
sponsors in the description. And now, let me leave you with
some words from Steve Jobs. "I think the biggest innovations of the 21st century will
be at the intersection of biology and technology. A new era is beginning." Thank you for listening, I hope to see you next time.