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 this if you have hydrogen and co2 and you put them together in a falcon tube and you warm it up to say 50 degrees centigrade and you put in a couple of catalysts and you shake it nothing'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 it's because that's where you need the spark the following is a conversation with nick lane a biochemist at university college london and author of some of my favorite books on biology science and life ever written including his two most recent titled transformer the deep chemistry of life and death and the vital question why is life the way it is this is 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 uh we little humans can ask of ourselves how did life originate on earth you could 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 opinions grounded in science um but they're still really at this point their opinions because there's so much stuff to know that all we can ever do is get a kind of a small slice of it and it's the context which matters so i can give you my answer

my answer is from a biologist's point of view that has been missing from the equation over decades which is well what does life do on earth what what why is it this way why is it made of cells why is it made of carbon why does it why is it powered by electrical charges on membranes there's all these interesting questions about cells that if you then look to see well is there an environment on earth on the early earth four billion years ago it 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 can drive the kind of chemistry that life does so it seems so beautiful and so so obvious um that i've spent the last 10 years or more trying to do experiments it turns out to be difficult of course everything's more difficult than you ever thought it was going to be but it looks i would say more true rather than less

true over that 10-year period i think i have to take a step back every now and then and think hang on a minute where's this going uh 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 think i'm talking about carbon i'm talking about cells and maybe you or plenty of people can say to me ah yeah but life can be anything i have no

imagination and maybe they're right but unless we can say why life here is this way and if those reasons are fundamental reasons or if they're just trivial reasons then we can't answer that question um so so i think they're fundamental reasons and i think we need to worry about them yeah there might be some deep truth to the puzzle here on earth that will resonate with other puzzles elsewhere that will 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 sharing a session on whether oxygen matters or not in the history of life of course it matters but it matters most of the origin of life to be not there um as i see it we have this i mean life is made of carbon basically primarily um organic molecules with carbon-carbon bonds and the building block the lego brick that we take out of the air or take out of the oceans is

carbon dioxide and to turn carbon dioxide into organic molecules we need to strap on hydrogen and so we need an and this is basically what life is doing it's hydrogenating carbon dioxide it's taking the hydrogen the bubbles out of the earth in these hydrothermal vents and it sticks it on co2 um and it's kind of really as simple as that um and actually thermodynamically there's the the thing that i find most troubling is that you if you do these experiments in the lab the molecules you get are exactly the molecules that we see at the

heart of biochemistry in the heart of life is there something to be said about the earliest origins of that little uh potion that chemical process what really is the spark there there isn't a spark um there is a continuous chemical reaction and there is kind of a spark but it's a continuous electrical charge which helps drive that reaction so literally spark uh well the charge at least but yes i mean a spark in that sense is um we're we tend to think of in terms of frankenstein we tend to think in terms of electricity and

one one moment you zap something and it comes alive and what does that really mean you've it's come alive and now what's sustaining it well we are sustained by oxygen by this continuous chemical reaction and if you put a plastic bag on your head then you've 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 this if you have hydrogen and co2 and you put them together in a falcon tube and you warm it up to say 50 degrees centigrade and you put in a couple of catalysts and you shake it nothing's gonna happen but thermodynamically that is less stable two gases hydrogen and co2 is less stable than cells what should happen is you get cells coming out um so why doesn't that happen is because of the kinetic barriers is because 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 there's a long distance to go from the 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 you to 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 i would i would talk about growing protocells as soon as we in introduce even random bits of information into into there i'm

thinking about rna molecules for example it doesn't have to have any information 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 but the system so that's when it becomes alive to my mind that's encompassed into like um an object that keeps information and involves that information over time or changes that information over time yes exactly in response to

that 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 possibly started in multiple locations on earth it's possible to start on multiple occasions um there's two provisos to that one of them is oxygen makes it impossible really for life to start so as soon as we've got oxygen in the atmosphere then life isn't going to 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

i start in these vents now and the answer is you've got if you want hydrogen to react with co2 and there's oxygen there hydrogen reacts with oxygen instead it's just you know you you get an explosive reaction that way it's rocket fuel so it's never going to 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 have been multiple origins and they all just disappeared um but there's a very interesting deep split in life between bacteria and what

are called archaea which look just the same as bacteria 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 uh 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 have d they both have dna the genetic code is identical in them both the way in which it's uh transcribed into rna into the copy of 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 what kind of processes could drive that divergence very

early on um 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 uh there's probably probably many unsuccessful attempts at only one really successful attempt can you explain why that divergence makes you think there's one answer uh one common ancestor okay can you describe that intuition i'm a little bit unclear about why the diver 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 if it

was if if you've 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 going to kind of take over the world and and wipe out everything else and so you what you would see would be a single common ancestor for all of life but with you know lots lots of different vent systems all

kind of vying to create the first life forms you might say so this thing is a cell a single cell well we're always talking about populations of cells but yes these are cell organisms but the fundamental life form is a single cell right so like or so they're always together but they're alone together yeah there's a machinery in each one individual component that if left by itself would still work yes yes yes it's the unit of selection is a single cell but selection operates over generations and changes over generations in populations of cells so it

would be impossible to say that a cell is the unit of selection in the sense that you unless you have a population you can't evolve you can't change right but there was one chuck norris it's an american reference yeah uh cell that made it out of the vents right or like the first one so imagine then 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 um 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 in all these different vents so either they all have the same code and two cells spontaneously merge from different places or two 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 came out that's kind of a bit strange uh so how did they come

out well they come out because what you're doing inside event is you're relying on the electrical charges down there to power this reaction between hydrogen and co2 to make yourself grow and when you leave the vent you've got to do that yourself you've got to power up your own membrane and so the question is well how do you power up your own membrane and the answer is well you need to pump you need to pump ions to give an electrical charge on the membrane so what do the pumps look like well the pumps look different

in these two groups it's as if they they both emerge from a common ancestor as soon as you've got that ancestor things move very quickly um and and divergently why does the dna replication look different well it's joined to the membrane the membranes are different the dna replication is different because it's joined to a different kind of membrane so there's interesting you know this this is detail you may say but it's also fundamental because it's about the two big divergent groups of life on earth that seem to have diverged really early on it all started

from one organism and then that organs just start replicating the heck out of itself with some mutation of the dna so like there's some um there's a competition through the process of evolution they're not like trying to beat each other up they're just they're just trying to live they just replicate us yeah well you know let's not minimize their yeah 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 a kind of an outgrowth of the earth you might say of course the

aliens would describe us humans in that same way they might be right primitive life it's just it's just ants that are hairless mostly hairless overgrown ants overgrown ants okay um what do you think about the idea of panspermia that 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 uh so so pseudotranspermia the idea that you know the chemicals

the amino acids the nucleotides are being delivered from space well we know that happens it's unequivocal they're delivered on meteorites comets and so on um so what do they do next that's to me the question and well what they do is they stock a soup like presumably they land in a pond or in an ocean or wherever they land and then you end up with a you know best possible case scenario is you end up with a super nucleotides and amino acids and then you have to say so now what happens and the answer is

oh well they have to go become alive so how did they do that you may as well say then a miracle happened i don't believe in soup i i think what we have in a vent is a continuous conversion a continuous growth a continuous reaction continuous converting a flow of molecules into more of yourself you might say even if it's a small bit so you've you've got 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 uh soup all the way down isn't it also no no i mean soup almost by definition doesn't have a structure but soup is a collection of ingredients that are like randomly yeah they're not i mean we have chemistry going on here we have metadata forming which are which are you know effective oil water interactions okay so it feels like there's a direction to a process like a director there are there are directions to processes yeah and if you are com if you're starting with co2 and you've got two reactive fluids being brought

together and they they react what are they going to make well they they make carboxylic acids which include the fatty acids that make up the cell membranes and and they form directly into bilayer membranes they form like soap bubbles it's spontaneous organization caused by the nature of the molecules and and those things are capable of growing and are capable in effect of being selected even before there are genes we have this so we have a lot of order and that order is coming from thermodynamics and the thermodynamics is always about increasing the entropy of the

universe but if you have if you have oil and water and they're separating you're increasing the entropy of the universe even though you've got some order which is the soap and the water are not not miscible now to come back to your first question about um panspermia properly um that just pushes the question somewhere else that just even if it's true maybe life did start on earth by panspermia but but so what are the principles that govern the emergence of life on any planet we it's an assumption that life started here and it's an assumption

that it you know it started in a hydrothermal vent or it started in a terrestrial geothermal system the question is can we work out a testable sequence of events that would lead from one 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 the fundamental question of past sperm 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 or well that's of course you would say that as a human uh but there could be aliens right now chuckling at that idea maybe you need some special um special sauce special elsewhere sauce your senses we have everything i mean this is precisely the the question so i i like to when when i'm talking in schools i like to start out with the idea of we make we can make a time machine we go back four billion years and we go to these environments that people talk

about we go to a deep sea hydrothermal event we go to a kind of yellowstone park type place environment and we find some slime that looks like we can we can test it it's made of organic molecules it's got a structure which is not obviously cells but you know it's is 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 this is a stepping stone and that's not us that 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 because we're never going to build that time machine is to have an intellectual framework that can explain step by step experiment by experiment how we go from a sterile inorganic planet to living cells as we know them and in that framework every time you have a choice it could be this way or it could be that way or you know there's lots of possible forks down that road um did it have to be that way could it have

been the other way and would that have given you life with very different properties um and so if you if you come up with a you know it's a long hypothesis because as i say we're going from really simple prebiotic chemistry all the way through to genes and molecular machines that's a long long pathway and nobody in the field would agree on the order in which these things happened which is not a bad thing because it means that you have to go out and do some experiments and try and demonstrate that it's possible or not

possible 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 i mean that's a perception that's our romanticization of things are always better 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 are 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 four billion years later they look exactly the same so about four billion years ago bacteria started to to really run the show and then nothing happened for a while nothing happened for two billion years yep then after two billion years we see another single event origin if you like of of our

own type of cell the eukaryotic cell so cells with a nucleus and loss 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 four billion years ago and something happened two billion years ago but the bacteria themselves didn't change they remain bacterial so there is no trajectory

necessary trajectory towards great complexity in human beings at the end of it it's very easy to imagine that without photosynthesis arising or without eukaryotes arising that a planet could be full of bacteria and nothing else we'll get to that because that's a brilliant invention and there's a few brilliant invention along the way but what is life if you were to show up on earth but to take that time machine and you said asking yourself the question is this a stepping stone towards life as you step along when you see the early bacteria how would you

know it's life is and then this is really important question when you go to other planets and look for life like what uh what is the framework of telling the difference between a rock and a bacteria 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 one question approaching me there's no answer so there's no i mean there's lots of there are at least 40 or 50 different definitions of

life out there and most of them are well convincingly obviously bad in one way or another um uh i mean there's this phrase i i can never remember the exact words that people use but there's a nasa uh working definition of life uh which more or less has a a system which is capable of of a 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 i know what they're getting at i know what they're trying to say but

but i pick a hole in that and there's you know there's always wags who say but you know by that definition a rabbit is not alive only a pair of rabbits would be alive because a single rabbit is incapable of copying yourself there's all kinds of pedantic silly but also important objections to any hypothesis the real question is what what is you know we can argue all day or people do argue all day about is is a virus alive or not and it depends on the content but most biologists could not agree about that so

then what about a jumping gene a retro element or something like this even simpler than a virus but it's capable of converting its environment into a copy of itself and that's about as close it's not a definition but this is a kind of a description of life is that it's it's able to parasitize the environment and that goes for plants as well as animals and bacteria and viruses um to make a a 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 the way evolution is so it is extremely powerful process of evolution which is basically make a copy yourself and sometimes mess up a little bit okay that seems to work really well i wonder if it's possible to mess up big time mess up big time as a standard that's the default uh it's called the hopeful monster and you know this doesn't work in principle it can actually it turns out i would say that this is due a re-emergence this is some amazing work from

michael levine i don't know if you came across him but uh you if you haven't interviewed him you should interview him yeah uh yeah about yeah i'm talking to him in a few days oh fantastic i mentioned off yes there's some people that anja if i may mention uh andre kapathi is a friend who's really admired in the ai community said you absolutely must talk to to michael and to nick this is so this of course i'm a huge fan of yours so i'm really fortunate that we can actually make this happen anyway well michael

levin is doing amazing work uh basically about the way in which electrical fields control development um and he's done some work with planarian worms so flatworms well 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 um one 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 of head um 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 a shift it but for it to be a speciation for it to to continue for it to to give rise to a different morphology over time then it has to be perpetuated so that shift that change in the in in 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 and so the likelihood it would be lost but but there will 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 kind of trying to mathematize a definition of life and saying how many steps the shortest amount of steps it takes to build the thing almost like an engineering view of it i like that view um because i think that in a sense that's not very far away from what it what what what a hypothesis needs to do to be a testable hypothesis for the origin of life you need to spell out here's

here's each step and here's the experiment to do for each step the idea that we can do it in the lab some people say oh well i've you know we'll have created life within five years but you know ask them what they mean by life um we have a planet four billion years ago with these vent systems across the entire surface of the planet and we have millions of years if we wanted i have a feeling that we're not talking about millions of years i have a feeling we're talking about 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 a you know a planet uh doing similar chemistry you asked about a trajectory the trajectory is the planetary trajectory the planet has properties it's basically it's got a lot of iron at the center of it it's got a lot of electrons at the center of it it's more oxidized on the outside partly because of the sun and partly because the heat of volcanoes puts out oxidized gases so the planet is a battery it's a giant battery

um 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 um and it's uh 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 in what happens in water the chemistry that happens in water some some will be miscible with water and will form membranes and will form insoluble structures and you

know water's a nobody really understands water very well um and it's uh 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 is likely to be is just kind of bulk bulk water how fundamental is water to life would you say i would say pretty fundamental um i wouldn't like to say it's impossible for life to start any other way but water is everywhere water is extremely good at what it does and carbon

carbon works in water especially well so those things and carbon is everywhere so those things together make me think probabilistically if we found 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 pot of water a pretty damn good indication that life has is either exists here or has once existed here 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 of bringing those electrons from inside to the outside it needs to turn over its surface it needs to make that water work and turn it into hydrogen so i think you need a living planet but once you've got the living planet i think the rest of it uh is kind of thermodynamics all the way so if you were to run earth over a million times up to this point maybe beyond to the end let's

run it to the end uh what is it uh how much variety is there you kind of spoke to this trajectory that the environment dictates like chemically i don't know in which other way um spiritually like dictates kind of the direction of this giant machine that seems uh chaotic but it does seem to have order in the steps it's taking uh how much how often will life how 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 that's how many times you say you want to run it a million times um i would say at least a few hundred thousand will get bacteria again oh wow um nice because i i think there's some level of inevitability that a wet rocky planet will give rise through through the same processes to something very close i i think this is not something i'd have thought a few years ago but we're 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 um there are patterns that you can discern in the co or he has discerned in the code that if you if you think about them in terms of we start with co2 and hydrogen and 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

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 potentially that's that's really exciting if that's if that's the case okay but then bacteria we've got then we've got bacteria yeah um how easy is photosynthesis much harder i would say let's actually go there let's let's go through the inventions yeah um 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 the 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 this is you know the single greatest planetary pollution event in the whole history of 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 not in the sense that we know on earth so that's a really big invention in this huge intervention yes and it happened once there's a few things that happen once on earth and you know you're always stuck with this problem is it once it happened did it become so good so quickly that it precluded the the same thing happening ever again or are there other reasons and we really have to look at each one in turn and think what's why does it

only happen once in this case it's really difficult to split water it requires a lot of power and that power you're effectively separating charge across a membrane and the way in which you do it if it doesn't all rush back and and kind of cause an explosion right at the site requires really careful wiring um and that wiring it can't be easy to get it right because you know the plants that we see around us they have chloroplasts those chloroplasts were cyanobacterial ones those cyanobacteria are the only group of bacteria that can do that type

of photosynthesis so there's plenty of opportunity so not even many bacteria so who who invented photosynthesis that the cyanobacteria or their ancestors and there's not many um 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 um you can do it from iron you can take electrons so the early oceans were probably full of iron you can take an

electron from ferrous ion so iron two plus and make it iron three plus which now precipitates as rust uh and you take a a proton from the acidic early ocean stick it there now you've got a hydrogen atom stick it onto co2 you've just done the trick the trouble is you bury yourself in rusty iron and with sulfur you can bury yourself in sulfur one of the reasons oxygenic photosynthesis is so much better is 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 the we're eating plants um which are getting their energy from the sun and we're burning it with their waste products which is the oxygen so there's a lot of kind of circularity in that but with with without an oxygenated planet you couldn't really have

um predation you you don't 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 eukaryotic versus prokaryotic cells prokaryotes what 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 exciting so what what are they can you explain yeah so so so i mentioned bacteria and archaea these are both prokaryotes um they're basically small cells that

don't have a nucleus if you look at them under a microscope you don't see much going on if you look at them under a super resolution microscope then they're fantastically complex 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 then they're large superstructures effectively biofilms plated on top of each other and and you end up with quite quite large structures that you

can see in the fossil record but they they don't they never came up with animals they never came up with plants they they hear 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 a kind of supercharged cell which can have a much larger nucleus with many more genes all supported if you

think about you could think about it as a multi-bacterial power without the overhead so you've got 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 to to express to 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 throw 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 um but there's a 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 um and you can think of it as

a paired down power pack where the control unit is really being has been kind of paired down to almost nothing so you're putting out the same power but the the investment in in the overheads is really paired 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 four-fold in the number of genes but in terms of the the size of genomes and your ability to to make the

building blocks make the proteins we've gone up a hundred thousand fold or more so it's huge step change in the possibilities of evolution uh and it is it's interesting then that the only 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 we 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 and liver you switch off those and you switch on a different set and the standard evolution explanation for that is that you've you you're restricting conflict you don't have a load of genetically different cells that are all fighting each other um and so it works the trouble with bacteria 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 uh

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 a great importance in terms of the impact they had on life both uh it had a huge impact on life because if if that had not happened you can be certain that life on earth would be bacterial only and that took a really long time too it took two billion years yeah

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 from from just an informational perspective you you think bacteria have got they they structure their information differently so a bacterial cell has a small genome you might have 4 000 genes in it but a single e coli cell has access to about 30 000 genes potentially it's got a kind of meta genome where other e coli out there have got different gene sets and they can switch them around between

themselves and so you can generate a huge amount of variation and you know they've got more an e coli meta genome is larger than the human genome we own 20 000 genes or something so and they've had four billion years of evolution to work out what can i do and what can't i do with this 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 they've got much larger populations and they never

they never got around this problem so why can't they it seems as if you can't solve it with information alone so what's the what's what's the problem the problem is structure if if if cells if the very first cells needed an electrical charge on their membrane to grow and in bacteria it's this is 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 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 we're surrounded by lots of subsidiary energetic genomes that do do all the and they're the control units that are doing all the all the control of energy generation could this have been done gradually or does it have to be done the power pack has to be all intact and ready to go and uh it works i mean it's a kind of step changing the possibilities of evolution but it doesn't happen overnight it's going to 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 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 why switch what are the drivers here so there's a lot of there's a lot of times a lot of evolution but as soon as you've got cells living inside another cell what you've got is a is a new design you 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 uh more delegation like a hierarchical control of the whole thing and then and then somehow that leads to ability to have multi-cell organisms i'm not sure that you have hierarchical control necessarily but you you've got a system where you can 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 um it allows you it's it's a funny thing you to to have a to have a an animal where i have you know 70

of my genes switched on in my brain and i have different 50 switched on in my liver or something you've got to have all those genes in the egg cell at the very beginning and you've got to have a a 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've got to have a lot of genes in one cell and you've got to be able to maintain them and the problem with

bacteria is they don't get close to having enough genes in one cell so they would 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 coming into we know they don't because they're 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 did 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 big this is broad brush stroke that i'm talking about yeah generally speaking uh so how was uh so another you know fun invention us humans seem to uh utilize it well but you say it's also very important early on is sex so uh what is sex uh just asking for a friend 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 asked a couple of papers on sex yes yes what do you publish these biology is it biology genetics journals yeah this is actually pnas which is proceedings of the national academy broad big big picture everyone's interested in sex of biologists is to make sex dull yes yeah that's a beautiful way to put it okay so when was it invented uh it was invented with eukaryotes about two billion years ago um all eukaryotes share the same basic mechanism that 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 much going on there beyond that and then these are haploid which is to say we all have two copies of our genome and the the gametes have only a single copy of the genome so when they fuse together you now become diploid again which is to say

you now have two copies of your genome and what you do is you line them all up um and then you and then you double everything so now we have four copies of the complete genome and then we criss cross between all of these things so we take a bit from here and stick it on there and a bit from here and we stick it on here that's recombination um and and then we go through two rounds of cell division so we divide in half so now the two daughter cells have two copies and we

don't divide in half again now we have some gametes each of which has got a single copy of the genome and that's the basic ground plan for what's called meiosis and uh and enhancing 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 yeah find each other what is that like is that well you've got a few cells together so the bottom the bottom line on all of this is is is bacteria i mean it's kind of simple uh when when you when you've figured it out and figuring it out this is not me this is my phd student marco kolnagi um and uh and in effect if you if

you're doing lateral you're an e coli cell you've got 4 000 genes you want to scale up to a eukaryotic size and i want to have 20 000 genes um and i'm and i need to maintain my genome so it doesn't get shot to pieces by mutations and i'm going to 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 because i'm not sentient but i know i 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've got a small genome the chances of you picking up the right bit of dna from the environment is much higher than if you've got a genome of 20 000 genes to do that you've effectively got to be picking up dna all the time all day long and nothing else and you're still going to get the wrong dna you've got to pick up large chunks and in the end you've got to align them you're forced into to kind of phrase um so yeah

uh so it's it's so there is a kind of uh um incentive uh if you want to have a large genome you've got to prevent it mutating to nothing that will happen with bacteria there's another reason why bacteria can't have a large genome but as soon as you give them the power path as soon as you give your carotid cells the power pack that allows them to increase the size of their genome then you face the pressure that you've got to maintain its quality you've got to stop it just mutating away what about sexual selection

so the the finding uh like uh i don't like this one i don't like this one this one seems all right like what's the the the is is it at which point does it become less random it's hard to know because your courier's just kind of floated around i'm just kind of have yeah there's everything that's their section in single cell do you characterize the probably is it's just that i don't know very much about it by the time you don't hang out with the acquisitions well i do all the time but you know but

they can't communicate with them yet yeah peacock or something yes um the kind of standardize is not quite what i work on but the standard answer uh is that it's female mate choice she is looking for good genes um and and if you can have a tail that's like this and and still survive still be alive not actually being taken down by the nearest predator then you must have got pretty good genes because despite this handicap you're 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 like uh how you advertise yourself that you're worthy yeah of uh absolutely so one big advertisement is the fact that you survived it all let me give you one one beautiful example uh of an algal bloom and this can be this can be a cyanobacteria it can be in bacteria so so if if suddenly you you know you pump nitrate or phosphate or something into the ocean and everything goes green you end up with all this uh algae growing there um

a viral infection or something like that can kill the entire bloom overnight and it's not that the virus takes out everything overnight it's that most of the cells in that bloom kill themselves before the virus can get onto them and it's through a form of cell death called programmed cell death and we we do the same thing this is how we have the different you know the gaps between our fingers and so on it's how we craft synapses in the brain um it you know is fundamental again to to to multicellular life they have the

same machinery in these in these algal blooms how do they know who dies the answer is they will often put out a toxin and that toxin is a kind of a challenge to you either you can cope with the toxin or you can't if you can cope with it you form a spore and you will go on to become the next generation you you you form a kind of a resistance spore you sink down a little bit you get out of the way you're out of the out out of you can't be attacked by a

virus if you're a spore at least not so easily whereas if you can't deal with that toxin you pull the plug and you you you you trigger your death apparatus and you kill yourself because it's truly life and death yeah so it's really it's a challenge and this is a bit like sexual selection it's not so they're all pretty much genetically identical but they've had different life histories so have you had a you know a tough day did you did you happen to get infected by this virus or did you run out of iron or

did you get a bit too much sun whatever it may be if this extra stress of the toxin just pushes you over the edge then you have this binary choice either you're the next generation or you kill yourself now using this same machinery it's also actually exactly the way i approach dating but that's probably why i'm single okay uh what about if we can step back dna just mechanism of storing information rna dna yeah how big of an invention was that that seems to be you that seems to be fundamental to like something deep within

what life is is the ability as you said to kind of store and propagate information but then you also kind of infer that with your and your students work that there's a deep connection between the chemistry and the ability uh to have this kind of genetic information so how big of an invention is is it to have a nice representation a nice hard drive for info to pass on huge i suspect uh i mean but when i was talking about the code you see the code in rna as well and rna almost certainly came first

um 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 kind of cuts out this chicken and egg loop so dna it's possible it's not that special so our rna 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 how do how do you distinguish this is something where actively thinking about how do you distinguish between you know a random population of rnas some of them go on to become messenger rna that this is the the transcript of the code of the gene that you you want to make some of them become transfer rna which is which is the kind of the unit that holds

the amino acid that's going to be polynomial 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 some kind of phase transition going on there what's 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 of rna viruses like hiv for example they're pretty small and and so there's a limit to

how complex life could be unless you come up with dna which chemically is a really small change but how easy it is to make that change i don't really know as soon as you've got dna then you've got an amazingly stable molecule for information storage um and you can do absolutely anything but how likely that transition from rna to dna was i don't know either how much possibility is there for variety in ways to store information because it seems to be very specific characteristics about the the programming language of dna yeah there's a lot of

work going on what's called xenodna or rna can we replace the the bases themselves the the letters if you like in in in rna or dna can we replace the backbone can we replace for example phosphate with arsenate can we replace the sugar ribose or deoxyribose with a different sugar and the answer is yes you can um 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 um 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 um and and they work uh and i'm increasingly thinking it's that way that we're channeled towards ribose phosphate and and and the bases that are used but there are you know 200 different letters kicking around out there that could

have been used it's such an interesting question if you look at in the programming world in computer science there's a programming language called javascript yeah which was uh written super quickly it's a giant mess but it took over the world and it was sounds very biological it was it was kind of a running joke that like um like surely this can't be the it's a terrible programming language it's a giant mess it's full of bugs it's so easy to write really crappy code but it took over all of front-end development in the web browser if

you have any kind of dynamic interactive website it has it's usually running javascript and it's now taking over much of the backend which is like the serious heavy duty computational stuff and it's become super fast with the different compilation engines um that are running it so it's like it really took over the world it's very possible that this initially crappy uh derided language actually takes everything over and then the question is did human civilization always strive towards javascript or was javascript just the first programming language that ran on the browser and still sticky the first

the first is the sticky one and so it wins over anything else because it was first and we i don't think that's answerable right but it's good to ask that i suppose in the lab you can't you can't run it with programming languages but in biology you can probably do some kind of um small scale evolutionary tests to try to infer which which is which yeah i mean in a way we've we've got the hardware and the software here and and the the hardware is maybe the the dna and the rna itself and then the

software perhaps is more about the code is did the code have to be this way could it have been a different way yeah people talk about the optimization of the code and there's some suggestion for that uh i think it's weak actually but you could imagine you could come out with a million different codes and and this would be one of the best ones um well we don't know this well i mean people have tried to model it based on the effect that mutations would have um so no you're right we don't know because that's

the thing that's a single assumption that a mutation is 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 it's hard to mess up in in the way you mess it up often is likely to produce interesting results so it's um are you talking about javascript or the genetic code now yeah well i mean it's almost you know biology is underpinned by this kind of mess as well you look at the human genome and it's full of stuff that

is really either broken or dysfunctional or was a virus once whatever it may be and somehow it works and maybe we need a lot of this mess you know we know that some functional genes are taken from this mess so what about you mentioned predatory behavior yeah we talked about sex what about violence predator and prey dynamics how uh when was that invented and uh poetic and biological ways of putting it like what how do you describe a predator-prey relationship is it a beautiful dance or is it a 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 delivibrio is one that lynne margulis used to talk about a lot um it's it's got a kind of a drill piece that drills through the wall and 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

yeah but it's not parasitic in that you need them to be still alive no no i mean predation is you kill them really murder parasite is so you kind of live on them okay so but it seems the predator is really popular uh um so what we see if we go back 560 570 million years before the cambrian explosion there is um what's known as the ediacaran fauna or sometimes they call vendo bions which is a lovely name uh and and it's not obvious that they're animals at all uh they're stalked things they often have

fronds that look a lot like leaves with kind of fractal branching patterns on them um and the thing is they've they're found sometimes 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 no 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 they're filter feeders and we know things you know sponges and corals and things are filter-feeding animals they're stuck to

the spot uh and little bits of carbon that come their way they they filter it out and that's what they're eating um so no predation involved in this beyond stuff just dies anyway and it feels like a very gentle rather beautiful rather limited world you might say there's not a lot going on there and something changes oxygen definitely changes during this period other things may have changed as well but the next thing you really see in the fossil record is the cambrian explosion and what do we see there we're now seeing animals that we would

recognize they've got eyes they've got claws they've got shells they're you know they're plainly killing things or running away um and and hiding um and 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 want to go there it's not done anybody any good in some ways maybe we maybe it does do good i don't want to make

an argument for nuclear arms but but predation as a as a mechanism forces organisms to adapt to change to be better to escape to to or to kill um if you need to eat then you've got to eat and you know a cheetah is not going to run at that speed unless it's unless it has to because the the zebra is capable of escaping so it leads to to much greater feats of evolution than would ever have been possible without it and in the end to a much more beautiful world and so it's not all

bad by any means the the but the thing is you can't have this if you don't have an oxygenated planet because if you it's all in the end it's about how much energy can you extract from the food you eat and if you don't have an oxygenated planet you can get about 10 out not much more than that um and if you've got an oxygenated planet you can get about 40 out and that means you can have instead of having one or two trophy levels you can have five or six trophies levels and that means

things can eat things that eat other things and so on and 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 i their 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 in this struggle it's a sorry statement but yes it's basically true and that's somehow is a catalyst from

an evolutionary perspective for creativity for creating more and more complex organisms that are better and better at survival i mean survival of the fittest if you just go back to that old phrase means death of the weakest um 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 the constraints the scarcity of the resources in the environment but that seems to be not nearly as good of a mechanisms mechanism for death than other creatures roaming about

in the environment when i say environment i mean like the static environment but then there's the dynamic environment of bigger things trying to eat you and use you for your energy it forces you to come up with a with a solution to your specific problem that you that is inventive and is new and hasn't been done before and so it forces i mean literally uh change literally evolution on 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 because 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 um be even more productive than evolution is because evolution is very wasteful like the amount of murder required to really test the good idea yeah genetically speaking is just a lot yeah

many many many generations morally we cannot base society on the way that evolution works that's that's not mentioned right 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 we you know in in in ancient greece we had we had the the the athens and sparta and city-states and then we had the renaissance and and nation-states and we you know universities compete with each other yes tremendous amounts of companies competing with each

other all the time it it drives innovation um and if we want to do it without all the death that we see in nature then we have to have some kind of societal level control that says well hit the some limits guys and these are what the limits are going to be and society as a whole has to say right we want to limit the amount of death here so you can't do this and you can't do that and you know who makes up these rules and how do we know it's it's a tough thing

but it's basically trying to find a moral basis for avoiding the death of evolution and natural selection and keeping the the the innovation and the and the richness of it i forgot who said it but that murder is illegal probably current finding it 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 um get rid of the

stuff that's not productive trying to almost accelerate evolution the same kind of thing that um uh 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 capitalism as a form is is basically about competition and and differential rewards but we society and you know we have a i keep using this world 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 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 uh in which case you then have to impose some kind of regulation that the bankers themselves will in an evolutionary manner exploit yeah it's we've been struggling with this

kind of idea of capitalism the the the cold brutality of capitalism that seems to create so much beautiful things in this world and then the the ideals of communism that seem to create so much brutal destruction in history and we struggle with ideas of well maybe we didn't do it right how can we do things better and then the ideas are the things we're playing with as opposed to people if a phd student has a bad idea we don't shoot the phds we just criticize their idea and i hope they improve you have a very

humane lab yeah yeah i don't know how you guys do it you know the way i run things uh it's always life and death okay so it is interesting about humans that there is an inner sense of morality which begs the question of how did homo sapiens evolve if we think about the invention of 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 five six million years or so and and and 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 and space-faring civilization so when we think about aliens we we we're kind of after something like ourselves or after a space-faring civilization we're not after you know zebras and giraffes and lions and

things amazing though they are but the the additional kind of evolutionary steps to go from large complex mammals monkeys let's say to to humans doesn't strike me as that longer a distance it's all about the brain and where's the 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 the yes the interactions really and there's some there's a guy at ucl uh called mark thomas who's done a lot of really beautiful work i think on on this kind of

question so i talk to him every now and then so my views are influenced by him um but a lot seems to depend on population density that the more interactions you have going on between different groups the more transfer of information if you like between groups of people moving from one group to another group almost like lateral gene transfer in bacteria the more expertise you're 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 but in human terms um i don't know what the actual factors were that were driving a a large brain but you know you can you can talk about fire you can talk about tool use you can talk about language and none of them seem to correlate especially well with the actual known trajectory of human evolution in terms of cave art and these kind of things that that seems to work much better just with with population density and

number of interactions between different groups all of which is really about human interactions human human interactions and the complexity of those but population density is the thing that increases the number of interactions but then there must have been inventions uh forced by that number of interactions that actually led to humans so like richard wrangham 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 when you're living together they don't like this the our early ancestors don't like the dictatorial aspect of a single

individual at the top of a tribe so they uh they they learn to collaborate how to uh basically create a democracy uh 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 uh versus the dictator i mean i think one of the what 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's really just

two aspects of human nature both of which are both we have both uh 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 and you could say that's a you know a drawing towards socialism or communism on the other side we really do care about ourselves we really do care about our families about working for something that we gain from and that's the capitalist side of it they're both

really deeply ingrained in human nature in terms of violence um and and interactions between groups yes all this dynamic of if you're interacting between groups you can be certain that they're going to be burning each other and all kinds of interact 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 going to do to to to to prevent being overrun by those marauding gangs from over there um and you look you look outside humans and you look at

chimps and bonnibos 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 they they there's basically a female society where the males are predominantly excluded and only brought in at the behest of the female we have a lot in common with both both of those groups and there's again tension there yeah and uh probably chimps more violence with bonobos probably more sex that's another tension [Laughter] how serious do i do do we want to be how much fun we want

to be uh 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 was it that how do we murder them how do we out-compete them um do we i made them i don't know i mean i i think there's unequivocal evidence that we mated with them yeah we always try to meet with everything yes pretty much there's some interesting the first sequences that came along were in mitochondrial dna and that was back to about 2002 or thereabouts

what was found was that neanderthal mitochondrial dna was very different to human mitochondria that's so interesting 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 um and then the first full genomes were secrets maybe 10 years after that and they showed plenty of signs of mating between so so the mitochondrial dna effectively says no mating and the the nuclear genes say yeah lots of mating um but we don't know is that possible so can you explain the

difference between mitochondrial cell yes and new uh nucleus i've talked before about the mitochondria which are the power packs in cells these are the paired down control units is that 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 and they do a it's basically the control unit of energy production that's what is that's what it's doing it's a basic old-school machine that does and it's got genes that were considered to be effectively trivial

because they did they did a a very narrowly defined job but they're not trivial in the sense that that narrowly defined job is about everything is being alive yeah um so so they're much easier to sequence you've got many more copies of these things and you can sequence them very quickly um 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 um except in very very rare and strange circumstances um

and so it tells a different story and it's not a story which is easy to reconcile always um and and what it seems to suggest to my mind at least is that there was one way uh traffic of genes probably going from humans into neanderthals rather than the other way around why did the neanderthals disappear i i don't know i mean i i suspect that they were i suspect they were probably less violent less clever uh less populous less willing to fight i i don't know i mean i i think it drove them to extinction

at the margins of europe 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 um uh the more isolated one you know like what dynamics results in more productivity and we i suppose we'll never know it's 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 being 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 uh how big are those inventions in the history of life on earth vision movement uh 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 and you know you can go in a series of steps uh from a a light sensitive spot on a flat piece of tissue to an eyeball with a lens and so on um if you assume no more than then i i don't remember this this was a specific model that i have in mind but it was you know

one percent change or half a percent change for each generation how long would it take to evolve and high as we know it and the answer is half a million years um it doesn't have to take long that's not how evolution works that's not a 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 where back to all the benefits that being able to see brings you and if you think you know philosophically what bats are doing with ecolocation 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 a retina and a and a cornea and so on basically they've got a camera type eye in a

single cell they don't have a brain um what they understand about their world is impossible to say but but they're capable of coming up with 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 we come around to your other point about manipulation sensory input and so on about you now now you you you 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 um 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 we're basically the entire uh the entire set of species on earth i think i i guess

are competing in a space that's an illusion that's distinct from this far away from physical reality as it is as defined by physics i'm not sure it's an illusion so much as a bubble i mean we we have a sensory input which is a fraction of what we could have a sensory input on um 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 the tree is physically there and if you walk into that tree you you know that there is

it's not purely a delusion there's some physical reality to it so it's a it's a uh 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 it's argument from evolution i don't know how much how 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 vibe all the same forces of evolution all the same competition the dynamics of uh between humans you can have but i don't know if um 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 uh you know the the idea um in in matrix movies and so on that the whole world is completely a construction um and we're fundamentally deluded it's it's difficult to say that's impossible or couldn't happen or and certainly we construct in our minds what the outside world is but we do it on input and that input i i would hesitate to say it's not real um 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 and they never see properly again because they've the the the neural wiring that underpins how we interpret vision never developed you know you need when you watch a child develop it walks right it walks into a table it bangs its head on the table and it hurts uh and now you've got two inputs you've got one pane 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've got the visual input and you put the three things together and think i don't want to walk into a table again so you're learning and 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 uh and same if you if you're in in in some kind of uh let's say computer construction of reality i'm not in my ground

here but if if you construct the laws that this is what reality is inside in inside this then you play by those laws yeah well i mean as long as the laws are consistent 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 the 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 uh hard drugs but prefer in a deep meaningful way in the way we we enjoy i mean i suppose the issue with the matrix i i imagine that it's possible to 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 is 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 and and joins up and makes 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 but we don't know how to use them we don't know 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 we're we're basically booting up the system so that it it can make head a 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 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 uh as a world that they're part of the brain is just not developed in that way so i can't make sense of new york in this physical reality either but yeah i mean but you said pain and 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 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 oh i'm sure we are yes okay so there's an imperative so whatever that reality is given to us like the table hurts fire's hot yeah i think we want to be deluded in a sense that we want to make a simple like einstein simple theory of the thing around us we want that simplicity and so um maybe the hunger for the simplicity is the thing that could be used to construct a pretty dumb simulation that that tricks us so maybe tricking humans doesn't require building a universe no i i don't i mean i

this is not what i work on so i don't know how close to it we are anyone working but i i agree with you but yeah i'm not sure that it's a morally justifiable thing to do but it's it's is it possible in principle um i think it'll be very difficult but i don't see why in principle it wouldn't be possible and i agree with you that it's it's um 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 kind of blunder around in a universe by ourself and understand the whole thing we're told by the people around us uh what things are and what they do and that you know language is 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 this the the thing the the spread of

ideas and the the the exchange of ideas i don't know and 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 partial 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 um 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 in organisms that's um yeah i mean i agree with you but we come really with this to consciousness yes and is there a distinction there because what you're saying the natural end point says we are indistinguishable that if you are capable of building a 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 um and i don't i don't have a strong view but i have a view um and i

i wrote about it in the epilogue to my last book because 10 years ago i i wrote a chapter in in a book called life ascending about consciousness and the subtitle of life ascending was 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 uh 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 um and i was left with the feeling that hey nobody knows and b there are two main schools of thought out there with a big kind of a skew in distribution one of them says oh it's a property of matter there's an unknown law of physics pan psychism 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 um 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 the other end is it's a it's an emergent property of a very complex central nervous system um and i am 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 um use it to to plaster over uh ignorance as a biochemist the question for me then was okay it's a 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 or 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 i've never seen anyone answer that question you know in a way that makes sense to me and that's an important question to answer i think if we want to understand consciousness that's the only question to answer because i you know i certainly a an ai is capable of out thinking and it's 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 our sense of what the world is in a 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 the 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 is one of the most celebrated lines ever written but what am i exactly and 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 the feeling in physical terms how does a discharging neuron give rise to a feeling of anything at all this is the heart 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 wonderous feasts of intelligence but we can't answer in principle whether such a supreme intelligence would experience joy or melancholy what is the quantum of solace i speaking

to the question of emergence you know there's just technical um uh there's a there's an excellent paper on this uh recently about the um this kind of face 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 um 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 face transition and we in the they're trying to construct the science of where that is like what is the good size of a neural network and why does such a face transition happen anyway that that sort of points to

emergence that there there could be stages where a thing goes from being oh you're you're very intelligent toaster to a toaster that's feeling sad today and turns away and looks out um out the window sighing having an existential crisis thinking you're marvin the paranoid android is that well no marvin is simplistic because marvin is just cranky yes uh it's so easily programmed yeah easily programmed non-stop existential crisis you're almost basically uh what is notes from underground but dusty like just just constantly complaining about life no they're capturing the full rollercoaster of human emotion the excitement

the bliss the connection um the empathy and all that kind of stuff and then the selfishness the the anger the the depression all that kind of stuff the 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 this i cannot possibly go on that feeling and then like after a nap you're feeling amazing that might be something that emerges so why would a nap make an ai being feel better the

first of all we don't know that for a human either right but we do know that that's actually true for many people much of the time you may be depressed when you do in fact feel better so oh you are actually asking the technical question there is there uh so that's a very there's a biological answer to that and so the question is whether ai needs to have the same kind of attachment to its body and bodily function and preservation of the brain's successful function of self-preservation essentially in some deep biological sense i mean i

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 um that 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 on balance um and that is something that's intrinsically difficult to simulate in all this richness i i would say um so so what is

death in all its richness yes the our relationship with death or or or the whole of it so which when you say richness of course there's a lot in that yeah which is hard to simulate what what's the what's part of the richness that's hard to simulate uh 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 um which i do in in in the book and and ask how do how how does a single cell in effect know it exists as an 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 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 are if you get this wrong um it's linked with this set of circumstances that i've just as an individual i have a moment of blind panic and run um as a bacterium or something you have a you know some electrical discharge that says blind panic and it 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 a response like that and it's easy to see how feelings come in through through the back door almost with with that that kind of um giving real-time feedback on your position in the world in relation to how how am i doing and then you you complexify the system and yes i have no problem with a with with phase transition and i you know can can all of this be done um purely by the language by the the the issues with how the system understands itself maybe it can i honestly don't know um but i

i you know the philosophers for a long time have talked about uh the possibility that you can have a zombie intelligence uh and that there are no feelings there but all everything else is the same um is i mean i have to throw this back to you really how do you deal with zombie intelligence so first of all i can see that from a biologist's perspective you think of all the complexities that led up to the human being the entirety of the history of four 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 their emotions are deeply connected and creating a human experience and from that you mix in consciousness and the fullness of it yeah uh 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 it's 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 this social society to like um and the the basic uh response of the baby is to cry a lot of the time cry uh to uh well maybe convince the humans to to protect it or to discipline it to teach it what if i mean uh we've developed a bunch of different tricks uh how to get our parents or 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 to learn the valuable lessons like the tables are still hard with corners so it can still run into them it hurts like how so ai needs to solve that problem not the problem of constructing this super complex organism that leads up uh so you to run the whole um you know to make an apple pie to build the whole universe you need to build the whole universe i think the the zombie question is uh it's something i would leave to the philosophers because uh and i

will also leave to them the definition of love and what is what happens between two human beings when there's a magic that just grabs them like uh nothing else matters in the world and somehow you've been searching for this feeling this moment this person your whole life that feeling um the philosophers can have a lot of fun with that one and also say that that's just uh you could have a biological explanation you can have all kinds of it's all fake it's uh actually ein 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 surest health feels very real and if my toaster makes me feel like it's the only toaster in the world 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 it get a better version of me because that toaster exists that sure as hell feels i mean is that psychologically different to having a dog no because i mean most people would

dispute whether we can say a dog i would i would say dog is undoubtedly conscious but but but some people there's degrees of consciousness and so on but people are definitely much more uncomfortable saying a toaster yeah conscious than a dog and there's still a deep connection you could say our relationship with the dog has more to do with anthropomorphism like we kind of project the human being onto it 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 uh

it's sad that it's it's delighted to see you again i don't have a dog by the way i don't know it's not that i'm incredibly good at using their eyes they do just that they are now i don't imagine that a dog is remotely as close to being intelligent as a as an ai intelligence but um it's certainly capable of communicating emotionally with us but here's what i would venture to say we tend to think because ad plays chess well yeah 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 non-stop people tell me how shitty people are driving no humans are incredible at driving uh 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 the ability to morph ideas together the ability to get angry at each other and then to miss each other like to create attention 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 a 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 with a decision to make and then it feels sad necessarily because it doesn't know what to do and i i certainly can't dispute that that may very well be how it works i think the only way to find out is to do it and just 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 an 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 which troubles me uh on reading it um uh noah harrari'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 a.i better at writing music that we appreciate the mozart ever called 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 it's a as a biochemist i find that argument 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 is capable of the same kind of uh emotional feelings about the world as as we are because the whole thing is an algorithm

and you can program an algorithm and 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 um 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 um based on an emotion we can just think i don't care i can't resolve this complex situation i'm going to 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 to to you and what you 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 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 um i might you know the idea that biochemistry is an algorithm is uh to me an over simplistic view there's a lot of things that the moment you say it it's irrefutable but it simplifies i'm sure it's an extreme and in

the process loses something fundamental so for example calling a universe an information processing system sure yes you could you could make that it's a computer that's performing computations but you're missing uh the the process of uh 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 are through the process of evolution are constructing even further complexity like in calling universe information processing machine you're 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 in a software system okay that runs the human body which i think is incorrect i think we're that is going to take so long i can't 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 saying with the emotions and the interactions and like like a dog makes us 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 yes it's not about whether you make the toast happy um no it has to so it has to be it has to be the toaster has to be able to leave me happy yeah because the toaster is the ai in this case is a very interesting the toaster has to be able to be unhappy and leave me that's essential yeah that's essential for my being able to miss the toaster if the toaster

is just my servant that's not 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 is for temporary and therefore it needs to be more selective what are those hangs out moving moments in the movies from when i was a boy was the the unplugging of hal in 2001 where that was the death of a sentient

being and hal knew it so i think we we all kind of know that that a sufficiently intelligent being is going to have some form of consciousness but whether it would be back 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 um more closely with with ai but are we really is is a is a dog really like a toaster or is there really some kind of difference there you were talking ab you know biochemistry is algorithmic uh but it's not

single algorithm and it's very complex of course it is so it may be that there's 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 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 uh 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 it's the whole package i mean to have a biochemical algorithm that runs a uh intelligent biological system you have to include the whole damn thing and it's pretty fascinating it comes from like from an embryo like the whole i mean oh boy i mean if you can um what is a human being because it's but if you look just some code and then you build and then that so it's dna doesn't just tell you what

to build but how to build it is it i mean the thing is impressive and the question is how uh difficult is it to reverse engineer the whole shebang very difficult i i would say it's don't want to say impossible but it is like it's much easier to build a human than to reverse engineer uh to build like a fake human human-like thing than to reverse engineer the entirety of the process the evolution of her i'm not sure if we are capable of reverse engineering the whole thing yeah if our if the human mind is

capable of doing that i mean i wouldn't be a biologist if i wasn't trying yeah um 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 a to a to the human mind and all the part system subsystems that are part of in the immune system and so on um this is something that you'll talk about i imagine um with uh with michael levin but the so little is known about 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 um and a lot of it seems to depend on the same intellect electrical interactions that i was talking about happening at the level of single cells and its interaction with the environment there's 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 our single cell develop into 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 uh but we're not going to reverse engineer a human being or the mind or any of these subsystems until we understand how this developmental process well how electricity

in biology really works and and if it is linked with feelings of with consciousness and so on that's the stamin in the meantime we have to try but but i think that's where the answer lies so you think uh it's possible that the key to things like consciousness are some of the more tricky aspects of cognition might lie in that early development the interaction of electricity and biology electrical fields 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 christie which are capable of of um reinforcing a field and generating fields over longer distances

um and nobody knows if that plays a role in consciousness or not there's reasons to argue that it could but frankly we we simply do not know and it's not taken into consideration you look at the the structure of the mitochondrial membranes in the brains of you know simple things like drosophila uh the fruit fly and they have amazing structures you can see lots of little rectangular things all lined up uh in in in 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 uh study the development of these in the uh in the petri dish development of organs do you think that's promising do you have to look at 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 in a dish is capable of experiencing some kind of feelings or even memories of its former brain again

i i have a feeling that until we understand how to control the electrical fields that that control development we're not going to understand how to turn an organoid into a real functional system but how do to get that understanding it's so 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 um i don't know if you're familiar with the work of deep mind and alpha fold 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 is not what i work on so i may have got this wrong but my understanding is that you you take the sequence the sequence of a protein and you try to fold it um in and there are multiple ways in which you 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 going to force this to go there now and then this one to go there and this one to come like and so you're forcing a specific conformational set of changes onto it as it comes out of the ribosome so by the time it's fully emerged it's already got its

shape and that shape depended on on on on the immediate environment that it was emerging into one letter as one one one amino acid at a time and i don't think that the field was looking at it that way and this is if 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 in biology is giving you a charged electrical environment that forces you to be this

way now did deep mind come up through patterns with some answer that was like that i've got absolutely no idea it bought to be possible to deduce that from the shapes of proteins it would require much greater 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 well they can figure that out that's really interesting about the exit tunnel but like sometimes we get lucky and our like just

second science the simplified view or the static view uh 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 and that seems to be the case in this situation with the the cool thing about proteins all the different shapes that 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 of uh proteins that uh which change the conformational state uh chaperone proteins and they're only used when when there's some presumably issue with how it came out of the exit tunnel and you want to do it differently to that so very often the chaperone proteins will go there and will influence the way in which it falls so there's two ways of doing it either you can 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 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 of course it's forced to come out this way and then the question would be well do different ribosomes have different charged environments what happens if a chaparral 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 in a billion different possible conformational states that this protein could have you're saying well it has this one because that was the only one it could take given its setting well yeah i mean there's currently humans are very good at that kind of first principles thinking oh yeah 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 how do solar systems come to be how do it what are the different forces that are required to make this kind of pattern emerge and then you start to invent things like gravity what i mean obviously i mixed up the ordering of of uh gravity wasn't considered as a thing that connects planets but um 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 um data and the question is with biology you know we kind of 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 that i was able to do that oh i'm not i'm not knocking it at all but uh but 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 kind of enters the chat and says i'll help you out with that can i give you another example of my own work um the the risk of getting a disease as we get older um 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 and we know a few genes that increase your risk of certain things and for for probably 20 years now people have been doing what's called g

wasps which is um genome-wide association studies so you you've effectively scanned the entire genome for any single nucleotide polymorphisms which is 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 come up 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 uh to explain the 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 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 percent uh and so the the gene similarities that you see should account for 50 of that known risk very often it accounts for less than a tenth 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 if we maybe there's 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 i mean you know maybe there's a billion of them for instance so 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's not uh it doesn't change very much but a few single letter changes in that mitochondrial dna it 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 to 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 want to 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 in fruit flies that they interact and produce big differences in risk so you can set uh you can set ai onto this question of exactly what uh you know how many of these base changes there are and this is one possible solution that maybe there are a million of them and

it does account for the great part of the risk well the other one is they aren't it's just not there that actually the risk lies in something you weren't even looking at and this is where human intuition is very important and just 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 uh that that that hang on a minute you might be

missing a whole other system here that's much bigger that's that's huma that's that's the moment of discovery of scientific revolution i'm giving up on saying hey i can't do something i've said it enough times about enough things i think there's been a lot of progress and uh 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 yes yes like we're so limited in so many ways uh that kind of in in what we feel like dumb ways like we're

not strong we're uh we're kind of um our attention our memory is limited our ability to focus on things is limited in our own perception 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 i'm hopeful that ai can capture some of that same magic but that magic is not going to look like uh deep blue playing chess no it's going to be more interesting but i don't think

it's going to look like a 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 the hypothesis is a story it's a testable story but but you know a new hypothesis is a leap into the unknown and it's a new story basically and it says uh this leads to this leads to that it's a causal set of of of storytelling it's also possible that the leap into the

unknown has a pattern of its own yes it is possible let's learn learnable i'm sure it is there's a nice uh book by arthur cursler on um on on the nature of creativity and 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 to a i'm not saying that's how it works but it's a nice idea and there's must be some truth in it um

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 is finding a new story that goes to an unexpected place and these are all aspects of what being human means to me um and maybe these are all things that that ai figures out for itself or maybe they're just aspects but i i just have the feeling sometimes that the people who are

trying to understand what to what we are like what weird what we 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 uh get a better better understanding of that i agree with you completely we try to build the thing and then we'll go hang on in a minute 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 i recently talked to magnus carlson the widely considered to be the greatest chess player of all time and he talked about alpha zero which is a system from deepmind that plays chess and he had a funny comment um he has a kind of dry sense of humor but he was extremely impressed when he first saw alpha zero play and he said that it did a lot of things that could easily be mistaken for creativity [Laughter] uh so he like refute as a typical human refused to give the system sort of it's

due because he came up with a lot of things that a lot of people are extremely impressed by not just the sheer calculation but the the brilliance of play so one of the things that um it does in really interesting ways is it sacrifices pieces so in chess that means you you 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 uh for us humans those risks are especially

painful because you have a fog of uncertainty before you so to take a risk now based on the 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 the alpha alpha zero takes those same kind of risks and does them even greater degree but of course it does it from a well you could easily uh 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 uh when we see creative play on the chessboard but the chessboard 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 adventuring biology psychology and expand into more and more complex systems i was um used to go running when i was a boy and fell running which is 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 uh and i i realized in trying to do this that um there's there's only really two two way 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 there's another there's a muddy puddle i'm going to 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 about exactly 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 going to break my leg if i keep doing this i've got to think about where i'm going to put my foot so you slow down a bit and try to bring those conscious mind in and then

you you do you crash you can't you can you cannot think consciously while running downhill and so it's amazing it's amazing how many calculations the mind is able to make and now the problem with playing chess or something if you were able to make all of those subconscious kind of forward calculations about what what is the likely outcome of this move now uh in the way that we can by running down a hillside or something is it 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 going to be eaten um whereas whereas trying to calculate multiple multiple moves into the future is not something we've ever been called on to do two or three four moves into the future is quite enough for most of us most of the time yeah yeah so the yeah just solving chess may not um we may not be as far towards solving the problem of uh downhill running as we might think just because we solved chess still it's beautiful to

see creativity humans create machines they're able to create art and art on the chessboard and art otherwise who knows how far that takes us so i mentioned andre carpathi 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 so let me ask you on the topic of uh alien life since we've been talking about life and we're a 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 that there is a trajectory going from simple simple cellular life like bacteria all the way through to humans it seems to me there's some big gaps along that way the the eukaryotic cell the the complex cell that we have is is the biggest of them but also photosynthesis is another the other another interesting gap is a long gap from from the origin of the eukaryotic cell to the first animals that was about a billion years uh maybe more than that

um a long delay in when oxygen began to accumulate in the atmosphere so from the first appearance of oxygen in the great oxidation event who were enough for animals to respire it was close to two billion years um why so long it 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 uh complexity and and um sentient life i don't think he's right doesn't not to say it's not going

to happen but i think it's not going to 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 happen really quickly on earth over the long so just 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 the 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 have happened and and that is something that that's because you're saying it's super important the eukaryotes but i'm saying tantamount to saying that it is impossible to build something as complex as a human being from bacterial cells i totally agree in some deep fundamental way but it's just like a one cell going inside another it's not so difficult to get to work right like well again it happened once um and if you

think about if you if you think i mean i'm in a minority view in this position most biologists probably wouldn't agree with me anyway but if you think about the the starting point we've 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 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 endo membrane it has it

has a little bit of stuff but not not that much and it takes up an endless inbound 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 cell it's photosynthetic they started out as algae in the oceans and so on so think of algal blooms single cell things you know the the basic uh the basic cell structure that it's built from

is exactly the same with a couple of small differences it's got chloroplasts 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 these 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 uh i'm a fungus in a soil spending 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 forced all kinds of change on 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 as soon as you've got endless imbalance 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 uh 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 you're leaning towards we just got really lucky in that one leap like we got 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 would i mean there's probably what five to ten 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 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 that's so

fast but i think that it's not going to happen inevitably and there's something you know it wasn't that's not the only problem with uh with with complex life on earth i mentioned oxygen animals and so on as well and even humans we came along very late you go back five 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 and 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 because that's an interesting perspective of uh how to look at human civilization but your sense 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 just like every sun like 90 percent of uh 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 and so wow i didn't even even think about that world there's a kind of thought that like one of the reasons it would be so exciting to find life on mars or titan or whatever it's like if it's life is elsewhere then surely statistically that life no matter how unlikely your query has multi-cell organisms sex violence what what else is extremely difficult i mean uh photosynthesis is figuring out some machinery that involves the chemistry and 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 i don't think natural i don't know what's more depressing bacteria everywhere nothing everywhere yes either of them are chilling 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 and what i'm saying may or may not be true so how would you feel if we discovered life on mars absolutely 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 the likelihood of life having gone to and fro between between mars and the earth is 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 they've been transit one way or

the other and that it was a it was a common origin of life on mars or on the earth and he went one way the other way the other way to see that question though would be to say well actually though the 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 uh 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 you think to tell the difference or 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 and we have uh d sugars and l amino acids right across all of life but lipids uh we have the bacteria have one one stereoisomer and the bacteria have the other the opposite stereoisomer so

it's perfectly possible to use one or the other one uh and the same would almost certainly go for i think george church has been trying to make life based on the opposite stereoisomer so it's perfectly possible to do and it will work um and if we were to find life on mars that was using the opposite stereoisomer 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

going to be weirder kind of life i wouldn't count on that because life started in deep sea hydrothermal vents it's harsh 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 um as the early earth would have been and it almost only 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 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 uh that we know on earth so the hard leap the hardest sleep the most important leap is from precarious to to eukaryotes eukaryotic what's the second if we're ranking what's what's the what's uh you gave a lot of emphasis on photosynthesis yeah and that would be my second one i think but it's it's 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 um 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 there's no problem with exploring whether you know you could have a separate origin that explored this whole domain over there that the bacteria had never gone into um so that kind of says that the reason that it only

happened once is probably because it's difficult because the wiring is difficult yeah um but then it it happened at least 2.2 billion years ago right before the goe maybe as long as three billion years ago when there are some people say there are whiffs of oxygen there's just kind of traces in the fossil in the in the geochemical record that say maybe there's a bit of oxygen then that's really disputed some people say he goes all the way back four billion years ago and and um it was the common ancestor of life on earth was

photosynthetic so immediately you've got you know groups of people who disagree over a two billion year period of time about when it started um but well 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 uh 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 um nothing much changed it's known as the boring billion in fact um uh probably

stuff was that was when you carries arose somewhere in there but it's uh 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 though there are um there 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 is going to 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 five to ten 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 intense 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 um but sulfurous lower down um and and that was stable certainly around the continental margins for more than a billion years uh it was not a state that led to progression in an obvious way um

yeah i mean it's interesting to think about evolution like what leads to stable states and uh how often are evolutionary pressures emerging 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 together in the next like 10 000 years like a lot of pressure uh it seems like earth like the boring building might be explained in two ways one it's super difficult to take any kind of next step and uh the second way 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 there was a snowball earth um so there was a planetary catastrophe on a huge scale where the the the ice was the the sea was frozen at the equator um and that forced change in one way or another it's not long after that 100 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 um is about sulfate being washed into the oceans which sounds incredibly parochial but the the issue is i mean that what the data is showing we can we can track roughly how oxygen was going into the atmosphere from um from carbon isotopes so there's two 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 one percent of carbon is carbon-13 which

is a stable isotope and then there's carbon-14 which is a trivial radioactive estrogen amount so 13 is one percent and life and enzymes generally you can think of carbon atoms as little balls bouncing around bing bong 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 is 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 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 what you're leaving behind

is more carbon 13 in the oceans and that precipitates out in limestone so you can look at limestones over these ages and work out what's the carbon 13 signal and that gives you a kind of a feedback on what they want 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 um was was

disappearing which is to say it was being oxidized um and if it's being oxidized it's consuming oxygen and that should so a big carbon 13 signal says that the ratio of carbon 12 to carbon 13 is is really going down which means there's there's much more carbon 12 being taken out and being oxidized sorry this is getting too complex but well it's a good it's a good way to estimate the amount of oxygen 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 yeah um and yet the rest of the geological indicators say no there's oxygen in the atmosphere so it's a kind of a paradox and 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 um is to assume that it what 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 anterior did yeah yeah so these are these are these are bacteria so they're oxidizing carbon organic carbon with sulfate passing the electrons onto sulfate that reacts with iron to form iron pyrites 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 a some kind of mineral so calcium sulfate minerals for example are evaporitic um and and um because there happened to be some continents some continental collisions mountain building this sulfate was pushed up the side of a mountain and happened to get washed into the ocean yeah so many happy accidents like that are possible statistically it's really hard you know maybe you can roll that in statistically or 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 and so on and so on so it's you know it's this kind of explanation of the cambrian explosion so uh let me actually say in several ways so you know folks who challenge the validity of the uh theory of evolution will give us an example now i'm not well studied in this but we'll give us an example the camera and explosion is like this thing is weird oh i just wait so by 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 uh 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 um anyway there's like five questions in there yeah is that the biggest mystery no i don't think that's a particularly big mystery really anymore i mean it's 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 um 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 we're seeing uh modern ecosystems and we're seeing arms races and we're seeing um we're seeing the full creativity of evolution unleashed and the so i talked about the boring billion nothing happens for for you know one and a half one billion years one and a half billion years um the assumption and this is

completely wrong this assumption is is that 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 it's completely wrong evolution gets stuck in a stasis and it stays that way for tens of millions hundreds of millions of years uh and stephen j gould used to argue this he called it punctuated equilibrium but he was doing it to do with animals and to do with the 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 two billion years was bacteria only you have the origin of life two billion years of just bacteria oxygenic photosynthesis arising here then you have a global catastrophe snowball earths and great oxidation events and then another billion years of nothing happening and then some 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 it's not lean is not geared towards increasing

complexity it's just everything is in balance and only when you have a catastrophic level of 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 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 uh you know one one one kind of tube into

a tube with knobbles on it into a tube with with with arms on it and then multiple arms and and then at one end is the head where that starts out as a swelling is you know it's not difficult consider intellectually to understand how these things can happen um it boggles the mind that it can happen so quickly but we're used to human time scales and what we need to talk about is generations of things that live for a year in the ocean um and and then a million years is a million generations and the

amount of change that you can do it can affect in in that period of time is enormous and we're dealing with large populations of things where selection is sensitive to pretty small changes and can uh so again what as soon as you throw in the competition of predators and prey and you're ramping up the 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 in biology is consciousness the big mystery in biology is conscious well intelligence is kind of a mystery too i mean you said biology not psychology because 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 this intelligence is necessarily that difficult i suppose i mean i see it as a form of computing and i don't know much about computing so i you don't know much about consciousness either so i i mean i suppose oh i see i see i see acid

that consciousness you do know a lot about as a human being no no i mean i i think i i can understand the wiring of a brain as a series of in pretty much the same way as a computer in in theory um in terms of um 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 i think we oversimplify intelligence i think the dance the magic of reasoning is as interesting as the magic of feeling we we

tend to think of reasoning as like very uh running a very simplistic algorithm i think reasoning is re the interplay between memory whatever the hell is going on the unconscious mind all of that um i'm not trying to diminish it in any way at all obviously it's extraordinarily exquisitely complex and but but i don't see a logical difficulty with how it works yeah no i i mean i agree with you but sometimes um yeah there's a big cloak of mystery around consciousness i mean let me compare it with with classical versus quantum physics the classical

physics is logical and you can understand the 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 is what just happened there yeah um i mean that that is the same it's like you understand mathematically the the notes of a musical composition that's intelligence yes but why makes you feel a certain way that is much harder to understand yeah that's that's really um but it

was it was interesting framing that that's a mystery at this at the core of biology i wonder who solves consciousness i tend to think consciousness will be solved by the engineer meaning anything the person builds it who tries keeps trying to build the thing uh versus biology is such a complicated system i feel like it's um 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 whole shebang 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 through from a field that was not related to so so if anyone you know is not going to be a biologist who solves consciousness uh just because biologists are too embedded in in in the nature of of the problem and then nobody's going to believe you when you've done it because nobody's going to be able to prove that this this ai is in fact conscious and and sad

in any case and 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 uh probability though of complex life i in one way i think why it matters is that my expectation i suppose is that we we will be over the next hundred years or so if we survive at all that ai will increasingly dominate and and pretty much anything

that we put out into space going looking for other well for the universe for what's out there will be ai won't be won't be us we won't be doing that or when we do it'll be on a much more limited scale i 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 um that's i don't see how a planet is going to give rise directly to ai we 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 um 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 uh maybe there's no issue but it it seems to me that the the the two are necessarily linked that are you you're not going to just turn a

sterile planet into an ai life form without the intermediary of the organics first so you have to run the the the full compute the 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 that's not a limiting factor right so i mean so there's 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 um because 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 you know it's not that i find it more compelling it's that i find more probable uh and i find all of them i mean

there's a lot of hand waving in this we just don't know uh so so i'm trying to read out from what i know about life on earth to what might happen somewhere else and 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 so i think the chances are pretty limited and the

chances of us surviving is pretty limited too 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 um so maybe the only thing that will survive from humanity will be ai and maybe once it exists and once it's capable of of effectively copying itself and cutting humans out of the loop um then maybe that will take over the universe i mean there's a kind of inherent

sadness to the way you describe that but isn't that also potentially beautiful that that's the next step of life um i suppose as 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 um yeah but there's there's some sadness yes probably because um because i think it comes down to the selfishness that we were talking about earlier on i

i am an individual with a a desire not to be kind of displaced from life i want to stay alive i want to be here um so i suppose the threat that a lot of people would feel is that we will just be wiped out so that we will be um that there will be potential conflicts between ai and humans and that that hey i 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 a.i so i would see bacteria

as being potentially a kind of primitive form of consciousness right so maybe the whole of life on earth to my mind is conscious it's capable of some form of feelings in response to the environment that's not to say it's intelligent though he's got his own algorithms for intelligence but nothing comparable with us i think it's beautiful what a planet what a sterile planet can come up with and it's astonishing that it's come up with all of this stuff that we see around us and and that either we or whatever we produce is capable of destroying

all of that yeah is it 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 i have that same [Music] i have the 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 in 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 that's a beautiful vision whether ai can do that or uh bioengineered humans uh can that's an exciting possibility and especially meeting other other alien civilizations in that same kind of way do you think do you think aliens have consciousness if they're organic so organic yes connected to caution i mean i i think any any system which is going to bootstrap itself up from planetary origins

i mean let me finish this and then come onto something else but uh from 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 of 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're you are far too parochial you you know you're thinking about life as carbon based here's a here's a life form which is kind of dust interstellar dust that on a on a on a solar system scale um and i you

know it's a novel but i felt enormously challenged by that novel because i hadn't occurred to me how limited my thinking was uh how how narrow-minded i was being and he was it was a great physicist with a completely different conception of what life could be and since then i've seen him attacked uh in in various ways and i i'm kind of reluctant to say the attacks make more sense to me than 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 of

the speed of light how quickly can something think if you're needing to broadcast across the the the solar system is going to be slow it's not going to hold a conversation with you on the kind of timelines that fred hoyle was imagining at least not by any easy way of doing it assuming that speed of light is a limit um and and then again you 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 a kind of an isolated um interstellar cloud again it's unlimited time and 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 um and i just have a feeling it's never going to 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 is that the difference between complexity and evolution so some of the work we're doing on the origin of life is is is thinking about how does uh 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 going to get is carboxylic acids then amino acids it's quite hard to make nucleotides um and it's possible to make them and it's been done and it's being 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 and 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 auto catalysis 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 um 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 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 um that's the kind of memory of the systems it's not yet 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 in my way it

remembers the stuff it tries like if you were to describe earth i i think evolution is something that we experience uh as individual organisms that's 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 um how would you describe it i mean well not as an organism i mean the idea of gaia is is lovely and james lovelock originally put gaia out as a as an organism that had somehow evolved uh 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 than um than than the science the science is now called earth systems science and it's really about how does the 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 it is working at a planetary level of um of 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 um 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 no it's stained by the sun right so i mean the so you don't think it it's possible to see earth as its own organism i think it's poetic and beautiful and i often refer to the to the earth as living planet but it's not in in biological terms an organism no if aliens were to visit earth would they 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 they would notice the trees at first because the ground i would i noticed the green yes yeah and then uh probably notice figure out the photosynthesis and then you notice cities second i suspect first they arrived at night they noticed it at first that's for sure it depends depends the time you uh you write quite beautifully in uh transformers once again i think you

open the book in this way i don't remember from space describing earth it's such an interesting idea of what earth is um you also i mean uh hitchhiker's guide summarizing it is harmless or mostly harmless it's a beautifully poetic thing you open transformers with from space it looks gray and crystalline obliterating the blue green colors of the living earth it is crisscrossed by irregular patterns and convergent striations there's a central amorphous density where these scratches seem lighter this quote 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 gray angular inorganic spreading yet at night they light up going 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 would be easy to see it that way wouldn't it um it uh wakes up at night they wake up it's strictly nocturnal yes i imagine that any aliens that are smart enough to get here would understand that uh they're 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 cells and i was trying to draw a comparison between the cell as a city and 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 um there are regulations and systems and whatever else but it's pretty loose um they have their own life their own way of developing over time they they and in that sense they're quite biological they're not it's there was there was a plan after the great fire of london christopher wren was uh was making plans not only for saint paul's cathedral but also to rebuild in in large parisian type boulevards a large part of the area of central london that was uh

was was was burned and it never happened because they didn't have enough money i think but it's interesting what was in the plan were all these boulevards um 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 it's kind of evolved entity that uh has the same kind of flux the same animation the same life so i think it's it's a it's a beautiful analogy but i wouldn't get too stuck with it as a as a matter of fact see i disagree with you i i i disagree with you i i think you're you are

so steeped 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 is very human-centric too that human the human organism is the epitome of life on earth i don't i don't know i i think there is some deep fundamental way in which a city is a living being in the same way that huma it doesn't give rise to an offspring city it's so i mean it's not it doesn't work by natural selection it works by if anything means it works

by um yeah but isn't it itself conceptually as a mode of being so i mean maybe memes maybe ideas are 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 the thing that that defines the collective intelligence of humanity is the ideas and maybe the way that manifests itself is cities maybe uh or societies or geographically constrained societies or nations and all that kind of stuff i mean

from an alien perspective it's possible that that is the more deeply noticeable thing not from a place of but what's noticeable doesn't tell you how it works i i think 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 we went from a hunter-gatherer's 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 then then yes there are other forms of evolution uh the forms of change

um but but cities don't 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 a kind of there is a hierarchy there and without the humans in the first place none of the rest of it exists it says you life is primarily defined by the the basic unit on which evolution can operate and that's a really unknown thing yes yeah uh and we don't know we don't have any other better ideas than evolution for how to create i never came across a better

idea than evolution but i mean maybe maybe i'm just ignorant and i don't know and there's you know you mentioned that's automator and so on and i don't think specifically about that but i have thought about it in terms of selective units at the origin of life and the difference between evolvability and and complexity or just increasing complexity but within very narrow narrowly defined limits the great thing about 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 the biophysical reality of what what kind of an organism you are what kind of a planet you live on and so on and and cities and and all these other forms that look alive and could be described as alive because they can't propagate themselves can only exist in 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 uh giant cloud among us i i kind of hope that i'm wrong about

a lot of this because i can't say that my world view is particularly uplifting um but in some sense it doesn't matter if it's uplifting or not science is about what's what's reality what's what's out there why is it this way uh and and i'm i think there's beauty in that too there's beauty in darkness you write about life and death uh sort of at the biological level is does the question of suicide why live does the question of why the human mind is capable of depression are you able to um introspect that from a

place of biology why our minds why we humans can go to such dark places why can we commit suicide why can we go um you know suffer suffer period but also suffer from a feeling of meaninglessness of um going to a dark place that depression can take you is this a feature of life or is it a bug um 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 uh 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 um it's probably a feature of mortality it's probably but beyond all of that i mean i guess there's two ways you could come at it there's one of them would be to say well you can effectively do do the math and come to the conclusion that it's all pointless and there's really no point in me being here any longer um 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 we have transient joy but with transient joy we have transient misery as well and and sometimes with everything in biology um 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 i doubt there's ever an escape from that it's the same with sex and everything else as well we're dealing with it whether whether you know you you can't regulate it so it's um any anything goes it's all part of biology amen to that let me uh on writing in uh your book power sex and suicide first of all can i just read off the books you've written 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 you 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 10 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 uh power sex and suicide you write about writing or about a lot of things but i i have a question about writing you write in the hitchhiker's guide to the galaxy ford perfect 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 quest as a side question would like to ask you what would be your summary of what earth is you're right his long essay on the subject is edited down by the

guide to read mostly harmless i suspect that too many new additions suffer 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 first edition of power sex suicide was published and i am resisting the temptation to make any lame revisions some say that even darwin lessen the power of his arguments in the origin of species there's 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 how do you advise other humans if you if you were to talk to young darwin or the young young you and uh just young anybody and give advice about how to write and how to write well about these big topics what would you say i said i mean i suppose there's a

couple there's a couple of points one of them is um what's the story what do i want to know what do i want to convey why does it matter to anybody and and very often the most the biggest most interesting questions um the child-like questions are the the one actually that everybody wants to ask but don't quite do it in case they look stupid um and one of the nice things about being in science is you the more the longer you're in the more you realize that everybody doesn't know the answer to these questions and

it's not so stupid to ask them after all yes um so so trying to ask the questions that i would have been asking myself at the age of 15 16 when i when i was really hungry to know about the world and didn't know very much about it and and um wanted to be wanted to go to the edge of what we know but um but be helped to get there i i don't want to be you know too much terminology and so i i want someone to keep a clean eye on what the question

is um beyond that i i've wondered a lot i've about who who am i writing for and that was in the end the only answer i had was was myself at the age of 15 or 16. 16 because even if you're you know you can you just don't know who who's reading but also where are they reading it are they reading it in the bath or in bed or on the on the metro or or are they listening to an audiobook do you want to have a you know a recapitulation every few pages because you

read three pages at a time or 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 going to do that's going to irritate people and in the end all you can do is just try and please yourself and that means what are these big fun fascinating in big questions and what do we know about it and and can i convey that and i kind of learned in trying to write um 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 uh and if you're trying to i've realized later on in in in in supervising various physicists and mathematicians who are phd students and i you know their math is way beyond what i can do but the process of trying to work out what are we actually going to model here what's going into this equation is a very similar one to writing what am i going to 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 then that can't be true um so you end up navigating your own path through this landscape and that can be thrilling because you don't know where it's going um and i'd like to think that that's one of the reasons my books have worked for people because this sense of the

thrilling adventure ride i don't know where it's going either so the 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 uh you know editing dial to mostly harmless to arrive at simplicity do you find the edit as productive or does it destroy the the magic that was originally there no i usually find i i think i'm perhaps a

better editor than i am a writer i i write and rewrite and rewrite and rewrite put a bunch of crap on the page first and then see the edit where it takes yeah but then then there's the professional editors who come along as well and um i mean in in transformer um the editor came back to me uh after i sent him two months after i sent the first edition he'd read the whole thing and he said the first two chapters prevent a formidable hurdle to the general reader go and do something about it yes

and it was the last thing i really wanted your editor sounds very eloquent in speech yeah well this wasn't this was an email but uh i i i 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 uh spent the summer this would have been i guess last summer uh 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 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 was still it's still difficult it's still biochemistry but but it has he ended up saying now he's got a barreling energy to it and i was you know because he'd been because he 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 was delighted could you give advice to young people in general uh 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 i'm um i'm sure you've gathered some wisdom you can um impart yeah just so the only advice that i actually ever give to my students um is follow

what you're interested in because they they're often worried that if they make this decision now and and do this course instead of that course then they're going to restrict their career opportunities and um there isn't a career path in science it's it's not i mean that there is but there isn't um there's a lot of competition there's a lot of death symbolically um 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 because 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 maybe on another continent and it's only two years anyway and and so and there's no there's no uh guarantee you're going to get a faculty position at the end of it so and there's always the next step to compete if you get a faculty position you get a tenure and with 10 you go full professor and

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 and then eventually you're all competing to i mean there's always a competition so there is no happiness happiness does not lie if you're looking into the future yes and if what you're caring about is a career then 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 uh and

i was made redundant twice so i i know that uh that you know there's no guarantee she got a career that way either yes so so live in the moment and try and enjoy what you're doing and that means really go to the go to the themes that you're most interested in and try and follow them as well as you can and and that tends to pay back in surprising ways i don't know if you've found this as well but i i found that um people will help you often if they see some light shining

in the eye and you're excited about their subject um and 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 they'll they'll use the network to help you out if you really care and you're not going to have a job two years down the line but if you 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 um 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 they're interested in that same thing that also have the light if you really are rigorous about this because i think it does take it's it doesn't it takes effort to make oh

you've got to be obsessive but 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 because depending on that takes some work as well yeah you know and look finding the right yeah finding the right mentors the collaborators because i think one of the problem with the phd processes people are not careful enough in picking their mentors those are people mentors and colleagues and so on those are people going to

define the the direction of your life how much you love a thing how much i mean the power of just like the few little conversations you have in the hallway it's it's incredible so you have to be a little bit careful in that sometimes you just get randomly almost assigned um 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 they kind of go together really yeah they do they really do but take that that that part seriously and probably in

the way you're describing it careful how you define success because uh you'll never find happiness in success and there's a lovely quote uh from robert lewis stevenson i think who said nothing in life is so disenchanting as attainment yeah so i mean in in some sense the the the true definition of success is you're getting to do today what you really enjoy doing just uh what fills you with joy and that's ultimately success so success isn't the thing beyond the horizon the big stat the the the big trophy the the financial i think it's 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 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 the 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 they're eaten away by the by the anger 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 got the chance to see that it also the more quote-unquote successful you are in that sense the more you run the danger of um growing ego so big that you don't get to actually enjoy the beauty of this life you start to believe that you figured it all out as opposed to i think what the ultimately the most fun thing is is being curious about everything around you being constantly surprised

and uh these little moments of discovery of enjoying 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 i couldn't agree more um so you know the the summary from harmless to mostly harmless in hitchhiker's guide to the galaxy how would you try to summarize earth and um you know if you were given if you have to summarize the whole thing in in a couple of sentences and maybe throwing meaning of

life in there like what why why why maybe is that a defining thing about humans that we care about the meaning of the whole thing i wonder i wonder if that should be part of the the the these creatures seem to be very lost yes they're always asking why i mean that's my defining question is why it was uh people used to made a joke i have a small scar on my forehead from a climbing accident years ago uh and the guy i was climbing with had dislodged a rock and he shouted something he shot

below i think meaning that the rock was coming down and uh and i hadn't caught what he said so i looked up and smashed straight on my forehead and um and everybody around me took the piss saying he he looked up to ask why yeah but that that's a human imperative that's part of what it means to be human look up to the sky and ask why and ask why uh so your question defined 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 mostly well it's interesting because like if you were to to write the hitchhiker's guide to the galaxy i suppose say our idea uh that we talked about the bacteria is the most prominent form of life throughout the galaxy in the universe i suppose the earth would be kind of unique and would require abundance in that case yeah it's profligate it's rich it's enormously enormously living so how how would you describe that it's not bacteria it's um eukaryotic yeah well i mean that's that's the technical term but it is

basically it's uh uh yeah and then how would i describe that i i've i've actually really struggled with that term because the word i mean there's a few words quite as good as eukaryotic to put everybody off immediately you start using words like that and they'll leave the room a krebs cycle is another one that gets people to leave the room but um but i've tried to think is there another word for eukaryotic that i can use and really the only word that i've i've been able to use is complex complex cells uh complex life

and so on and that word it it serves one immediate purpose which is to convey an impression but then it it it means so many different things just everybody that actually is lost immediately and so it's kind of well that's unnoticeable from the perspective of other planets that is the noticeable face transition of complexity is the eukaryotic what about the harmless and the mostly harmless is that kind of probably accurate on a on a universal kind of scale i don't think that uh 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 that's how many rockets i think uh it'll be still even then a while i think before uh before we disturb the fabric of time and space was the aforementioned andrei carpathi i think he summarized earth as um as a system where you uh hammer it with a bunch of photons the input is like photons and the output is rockets see if you just well that's a hell of a lot of photons before it was a rocket launcher yeah but like

you know maybe maybe in the span of the universe it's not it's not that much time and so 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 of

i mean we just need to slowly i mean i think we're more likely to do it inadvertently than than through a nuclear war which could happen at any time but um my fear is is we just don't know where the tipping points are and we will we we kind of think we're smart enough to fix the problem quickly if we really need to i think that's that's the overriding assumption that we're all right for now maybe in 20 years time it's going to 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 is too late and that however brilliant we are it's uh we missed the boat and just walk off the cliff i don't know i have optimism in humans being clever descendants oh i have no doubt that we can fix the problem but it's an urgent problem and we we need to fix it pretty sharpish and i i do have doubts about whether politically we are capable of coming together enough to uh not just in any one country but around the planet to just i mean

i know we can do it but do we have the will do we have the the the vision to uh to accomplish it that's what makes this whole ride fun i don't know not only do we not know if we can handle the crises before us we don't even know all the crisis that are going to be before us in the next 20 years the 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 one uh well yeah not at the end of world war one but by the 19 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 people worry about yes because there's a million things people worry about it and 99.99 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 sean 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 the 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 with russia and growing influence of africa and the weird dynamics of europe and then america falling apart through the political division fueled by uh recommender systems through twitter and facebook the whole beautiful mess is just fun and i think there's a lot 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 at least i have you know that's the process of evolution it's uh there was it all started with a chuck norris uh single cell organism that went out from the vents and was the parent to all of us and for for that guy or lady or both i guess 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 this was fantastic this is really amazing i

can't wait uh to read what you write next uh thank you for existing um and um 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