McCloskey Speaker Series – New Theories on the Origin of Life with Dr. Eric Smith

hey good evening welcome my name is Gerry Murdoch most of you in the room that or the many of you that know me mostly know me as that guy who's married to Geno Murdoch so but I'm also a board member here at the Aspen Institute and at the Santa Fe Institute at the Aspen Center for environmental studies this is a the second event of the 2015 McCloskey speaker series I want to thank Bonnie and Tom McCluskey family who are sitting right here thank you very much this is wonderful so tonight's speaker dr. Eric Smith has challenged disciplinary boundaries throughout his career first as an undergraduate at Caltech in math getting his degree in mathematics and in physics and then at the University of Texas Austin where he earned his PhD in high-energy physics while working on string theory and quantum gravity which was followed by appointments at Los Alamos and then he spent 11 years at the Santa Fe Institute has a full-time faculty member during his time at Santa Fe Institute I have a good fortune to meet him and in full disclosure I've been funding his work for over a decade his work in regards to the origin of life which we're going to hear about tonight and while at Santa Fe Institute he was also doing interdisciplinary work in geochemistry biochemistry and many topics related to complexity currently Eric is a professor and and researcher at the earth life Institute in Tokyo and he's also a external faculty member at the Santa Fe Institute his goal is to understand origin and nature of the living State through the many windows that science provides the physical geochemical biochemical ecological and evolutionary additionally he remains interested in the connections or correspondences between energy information and computation most of us think about life as being something created from other living things but much of Eric's work focuses on the time before biology when life on Earth emerge from geophysical and chemical processes the subject of tonight's talk is based on material from his upcoming book co-written by the legendary biologist Harold Morel wits which is entitled the emergence of the fourth geosphere to be published in 2016 by Cambridge University Press his work disrupts Francis Crick's notion that life was a happy accident indeed the material has consequences for the way we think about the relationship of the individual to ecology the big picture of orange and of life shows that ecosystems not individuals are carrying some of the most fundamental patterns of life furthermore the work leads us to understand that the nature of living State is different from the nature of individuality and that we have been wrongly conflating the two in our understanding of biology therefore we should strive to achieve a more ecology centered biology to help us guide our life in a more sustainable way within the biosphere finally both his upcoming book and tonight's talk will challenge us to rethink what is the nature of life without further ado let's welcome Eric Smith thank you so thank you Jerry and good evening everybody welcome you might think at the least that the problem of the origin of life how did life appear on an earth that previously had not had life is mostly a history problem what happened and when and where did it happen you could go a little bit beyond that and you might think of it as a problem of cause how did things happen and why the argument that I want to make tonight is that we actually need to go further than that the things that we've learned about the sort of technical problems of when where and how have caused us to realize that the nature of life is different from a lot of the patterns that we've traditionally used to think about it now the reason the origin of life problem is hard is that we do something in science that we also do in everyday life we put a big gap between the living things and the nonliving things it's very difficult to see across that gap how something like life could have come from something that was not alive so when we think about life we often think about it in these terms life is made of individuals they have agency maybe they have purpose or intentions that gives the biosphere direction even if the direction didn't come from the individuals it comes from evolution life is energetic its complex and it's endlessly fascinating compare that to rocks what do rocks do they just sit there sometimes for billions of years so what I want to argue to you tonight is that the conceptual gap between the nonliving world and living world is not real or it's not where we have tried to place it in the past the nonliving world is very active it's richly structured in its activity and the biosphere from the beginning all the way to the present is embedded in detail in the structure of that chemical activity of the rest of the planet we haven't recognized the connections because our ways of looking have been too small or they've been too short-term they've been on the scale of a human life or maybe we've looked in the wrong places but particularly in the last 30 years things that we've learned in a variety of different disciplines are changing the way we ask those questions and those are the things that cause us to reevaluate what we think the nature of life is and what we're trying to explain so tonight I want to cover four points first of all to understand the nature of life in the origin of life you have to understand its planetary context and that context is what I will call a great arc of disequilibrium on the scale of the whole planet now even though that disequilibrium or stress runs through all of the systems on the planet we can break it apart and we can make it comprehensible by doing something that geologists have done for more than a century we can divide the planet into geosphere z-- which are separate domains of states of matter and kinds of chemistry what we're looking for in the nature of life is actually at the level of the biosphere as a whole not at the level of its components of species or organisms or sub organismal components the conclusion that I want to leave us with at the end of the night is that the biosphere is the fourth geosphere we should understand it as a planetary subsystem and we should understand the emergence of life as a stage in planetary maturation akin to the stages that cause the other geo spheres to be separated from each other so in classical geology a lifeless planet can have three geo spheres the lithosphere from the word for rock is the solid bulk on earth this is almost all of the matter in the mass of the planet the state of matter is solid and the chemistry characteristic of the delay of the lithosphere is the chemistry of minerals and their changes second geosphere is the hydrosphere this is all of the watery domains water chemistry is very special it's very restrictive and as we've known forever water chemistry is fundamental to the nature of life and it's in part impart important because of all the things you can't do in water that you have to be distinctive the life does the third nonliving geosphere is the atmosphere this is the gas phase because it's cool and because it's at low density there are certain kinds of chemistry that are possible in the atmosphere that are not possible other places now the chemistry of the atmosphere is not actually very much like the chemistry of life but it turns out that it's really important to the great arc of planetary disequilibrium that will be central to our story and the fourth is the biosphere a lifeless planet will always have a lithosphere if it has enough volatile zazz they're called the liquids and gases it can also have hydro spheres or atmospheres I want to look at the earth as it is and everything that causes it to be different from a planet that only had the three lifeless geo seers and all of that difference is what I mean by the biosphere so it is organisms but not only organisms it's all of their ecological relations it's their history and it's all the changes that they have collectively brought about in the rest of the planet throughout its history so it's in the some rather than in the components that we look for the nature of the living State so I've said that there's not a gap that separates life conceptually from the rest of the earth but certainly the biosphere is different from the nonliving geo spheres it's different in many ways but if we had to choose one that's most important here's the one I would argue it is for the other geo spheres the lithosphere hydrosphere and atmosphere we can understand most of them in terms of their structure for the biosphere you can only really understand it as an organized state of activity in order to create an organized state of activity that goes beyond just structure you have to be in a circumstance that physicists call far from equilibrium and I'll explain to you in a minute what that means the important thing is that the disequilibrium we need to understand life are not something local they're not local in space and they're not local in chemistry they actually are built up on the scale of the whole planet so to give you a flavor for what is meant by near equilibrium or far from equilibrium I'll use something's a little of an analogy but it's an analogy that's mathematically faithful near equilibrium is like the ripples on a pond there may be activity that's caused by disturbances but most of what there is to understand can be understood from the structure of the flat surface before you start this is far from equilibrium think of the biosphere as surfing on a continuously renewed wave of energy flow that energy flow is needed to keep it up where it is it's needed to keep it organized now it's been understood forever that life requires a flow of energy to maintain itself but to say that something is required doesn't say that that's necessarily possible it only tells you what's impossible tonight I want to argue for something stronger I want to argue that the energy flows on earth brought the biosphere into existence it's as if the wave had created the surfer so traditionally when we come at the problem of the origin of life from the habits of biology we ask where is the surfer and what is the surfer like what I want to argue with here is that the right question should be where is the wave so the story of disequilibrium that makes sense of the origin of life doesn't start on the planet it actually starts in the formation of the solar system now when we look at the Sun the part we see is the photosphere photosphere is relatively cool it's only about 6,000 degrees Celsius which is about the same temperature as the core of the earth and it looks relatively smooth and flat like you see here occasional sunspots but if you were to look at the Sun in the x-ray with a movie you'd find a boiling cauldron of magnetic fluid because the Sun produces heat and the heat needs to convict and because it's electrically conductive you get loops of magnetism that boil up from the interior and WIPP plasma into the outer layers of the atmosphere this action can cause the middle atmosphere of the Sun called the chromosphere to go up to a hundred thousand degrees or more and it can elevate the corona to a million degrees or more so plasma at a hundred thousand degrees emits extreme ultraviolet radiation and at a million degrees or more it emits x-rays so if you could look at the Sun with a picture in the extreme UV in the x-ray this is actually what you would find the activity of the star like this is due to convection and the conductivity of the plasma but also to the rotation because this is a Coriolis effect the same as hurricanes and when stars are young when they're born they rotate much faster and they spin down over time so when the Sun was young all of this activity was actually more vigorous and more violent than it is today now that kind of hard radiation shapes planetary atmospheres and in particular it drives them far out of equilibrium from the planet that they surround so in particular ultraviolet and above will break water water is the h2o molecule where the HS are white and the O is red and it will separate the hydrogen from the oxygen hydrogen is a very light element and so anything will cause it to escape and the result is that you leave the oxygen behind this is actually a satellite photo of the earth taken with a filter for the emission lines that see hydrogen and what you can see is that our planet is surrounded by a halo of hydrogen it's continually escaping from it that to have major consequences because the rates of hydrogen loss that a star like our Sun produces will remove a volume of water comparable to the Earth's ocean in about a billion years so if you were Venus which is about our size but closer to the Sun a little bit warmer or if you were Mars which is smaller and has a weaker gravity to hold elements you would have wound up in the condition that they're in today with no surface water oxygen left behind that turns the dry surface a rusty red in about four and a half billion years the earth may be in this condition depending on how much water is on the inside which is something we don't know but for the time being the earth is a very unusual planet in the solar system and possibly more widely than that but why does any of this matter to the origin of life to answer that you need to know a little bit of chemistry but all you need to know is on this one slide and it's intuitive I promise in the periodic table of the elements we have many different kinds of animals some of the elements have a stronger what's called affinity for electrons than others and in particular important to our story iron is very ready to give electrons away to many other elements giving electrons away to something is called reducing that because electrons Haggen have a negative charge at the opposite end oxygen is very greedy --nt will steal electrons from many elements and so you can see the transfer of electrons from iron to oxygen in the Suites of minerals in the world iron metal which mostly doesn't exist at the surface has all of its electrons and they're loosely bound so they make a kind of a liquid and that's why iron is silvery and shiny and reflects light if you bring in a little bit of oxygen enough that there's one oxygen atom per iron atom it will transfer two electrons to the oxygen and we note that with a plus two on the iron and a minus two on the oxygen and you get this dull silvery mineral called this site which is no longer shiny because the free electrons are gone a little bit more so that you're in a mix between giving two and giving three electrons away and you have magnetite which is black this is what the original compasses were made of and if you give yet more you get this rusty red mineral called hematite which is one of the elements of rust now as we all know rust happens and the spontaneity of this electron-donating process is a source of chemical energy if you look at that at a planetary scale you realize that what happens is that hydrogen escape is turning our whole planet into a giant battery because this is how batteries work you take two different elements one of which gives electrons and one of which takes them and you force the electrons to flow through something so that you can harness the work in the earth in the interior region known as the mantle most of the iron is in this +2 state but near the surface it gets pulled to the +3 state by the oxygen that's continually made available as we lose water to hydrogen escape now on a quiet earth that battery would run down because even though you originally had oxygen to donate electrons at the surface that would basically weather over the same way you get a layer of oxide on an aluminum windowsill the only thing that allows the battery to be continually refreshed is that new material is delivered to the surface of the earth at the same time as hydrogen is continually scoured away out of the atmosphere but that redelivery brings a second kind of disequilibrium into the picture to understand the context for life so if you could look at a cross-section of the earth on hundred million year timescales so this is where human life is too short to see you would actually see cool material being brought down from the surface and you can barely see in this picture I apologize for the colors the yellow heat from the core being boiled up so the interior plastic rock of the mantle is constantly in convective turnover driven by this need to release heat if at the same time you could see the chemical composition of the rock you would find that the oxidized exhausted crust on the surface is being pulled down and remixed into the mantle while the electron giving iron mature the interior is allowed to come to the surface and make new crust so when you put all these processes together this is the picture you get of the big earth convection continually refreshes the surface rock at the same time as the solar radiation pulls the hydrogen away the important thing is that the new crust is not created uniformly everywhere it's created in concentrated centers which are called spreading centers or mid-ocean ridges beneath the ocean bottom the process of convection causes what are called plate tectonics the movement of the major plates around where they subduct they create earthquakes and volcanoes which deliver other concentrated new rock to the surface and when there are continents riding around on them they cause continental drift so this is a map of the bottom of the ocean showing its age the entire bottom of the ocean gets replaced about once every 250 million years as the continents go back and forth opening and closing in a cycle the mid-ocean ridges are these red regions of newly created crust in the Centers of all of the world's oceans and then the blue regions are the old crust that's diving back into the mantle as they do under Tokyo where I'm living now the sites where new crust is created are themselves very interesting because you're taking rock that's miles thick and you're twisting it and separating it and pulling it so they're filled with cracks and pores and in this domain seawater invades and it gets chemically altered by the rock the invasion sites and then the remix encoder comes back up are the places where a battery that accumulates over the entire planetary surface in bulk gets concentrated into these narrow ranges so this map shows you the same spreading centers on little red dots are the places where geologists have mapped out regions of active rock water interaction this is a tiny subset of the ones that are believed to exist but these now constitute the evidence we have about where the Earth's battery mostly flows and if you look at the electron transfer if you do a calculation from the interior to the atmosphere its concentrated at these little release points right around here so this is the importance of this is that this is where stress piles up in the world even though it's accumulated diffusely so up to this point we've closed half the gap hopefully I have convinced you that rocks don't just sit there that the earth is chemically active and that it's organized but before the 1970s even knowing all of this and much of this was understood roughly people still would not have been able to make a connection to the origin of life because life still seemed so different what I want to show you next is that's because up until about the 1970s we thought we understood the nature of life and our view of life was basically entirely upside down what's important about the last 50 years is that we've learned about an entire new part of the biosphere that we didn't understand and we've learned that it's that other part not us that gives the clues about where life came from and the real foundations of its nature so understandably for most of history when we think about the nature of life we think about things that are big enough to see because we didn't have microscopes and that means the plants and the animals in the fungi but what these all have in common is that ultimately they're all fed by this green forest here they all live off of the energy from sunlight and that's a problem because capturing sunlight is the most complicated thing living systems do and so we were never able to surmount that chicken egg problem how would you ever get up to something as complicated as the machinery that harnesses sunlight if you needed the sunlight energy to build that machinery in the first place but in 1977 Jack Corliss Richard von Hudson and Robert Ballard led an expedition to the Galapagos rift one of our spreading centers with the deep submersible Alvin which at that time was new they were drawn there because there had been measurements of the seawater overlying that were anomalously warm and so they suspect that there were rock water interactions taking place but they were completely unprepared for what they would see both about the geology and about the life hosted there immediately after those discoveries there were new hypotheses about how life had originated that are substantively much like what is mostly believed today but together with other changes that were going on around the same time in microbiology and molecular biology they completely changed our understanding of how the biosphere is organized on what was its history so what Alvin saw the first discovery was these thundering plumes of sulfide and heavy metal rich water coming up from the deep where they mix with cool seawater they precipitate these enormous chimneys that can be 45 or 60 feet tall this water would poison us immediately because of the metals and the sulfide that it's full of the temperature differences are extreme 350 degrees versus four degrees makes a mirror under this flange but the most amazing thing was the animal colonies that live around here the water would poison us but it's the source of energy for entire ecosystems like these tube worms and the shrimp that live around them now the red color you see here even though it looks like flowers has nothing to do with pigments because there's no light down here that's hemoglobin these are the worms lung that stick out into the water to perform gas exchange but the most important thing of all about these ecosystems is that the worms don't build life all of the life is built by bacteria the worms gather gases that the bacteria used to build their biomass in these shimmering zones of mixing that was a whole parallel biosphere that was not anticipated but the Alvin expedition did more than show us that there's more diversity in the world than we realized together with the other discoveries it forced us to reconsider what it is that determines living form there is a role for evolution in this but I'll come back to evolution second because it's actually not our first story the first story is that some of the patterns of life are written into the rules of chemistry and the planetary energy flows before there's ever material for evolution to act on the important conclusion in this will not only be new insights about organisms but also a new way to understand the ecosystems that makes them more fundamental than organisms so let me talk about typology suppose we had to play a game of 20 questions where I had to learn as much about some organism as possible in the fewest number of questions what should those questions be turns out they would not first be about its history my choice of the first two would be these I would first ask where does it get its energy does it get its energy from molecules that give electrons the way hydrogen does or from molecules that take electrons the way oxygen does then second I would ask how much do I learn if I only see the organism is the organism metabolically complete does it feed itself which is the condition called Auto trophy or is the organism in complete so that it depends on an ecosystem to provide it the condition called heterotroph II or being fed from somebody else because if it's incomplete then even if I study that metabolism I haven't understood what is sufficient to make life so the first thing you realize is that everything we use to think about is down in this one lower right corner here so they are not the norm the other thing you realize is that on this side they're all green or they eat something green or something that eats something green so these are the complicated guys and they were the ones we were trying to understand from these are the ones that were discovered in the deep subsurface and the bottoms of the oceans now if we look at the evolutionary view and we reconstruct history we realize that it's telling us the same story of course people and most of the things people know exists at a little tiny tip of this tree here and in fact anything that has more than one cell lives on these few branches that have slightly thickened lines everything else in the world is you know cells and before I don't know 600 million years ago that was all there was in the world more than that these are the only complex single-celled organisms the cells that have the simpler form of bacteria make up the blue and red branches that are the substance of the Tree of Life now the remarkable thing is as we have reconstructed the properties of these deep branches from the way their ancestors are left on the tips here we find that the bacteria that live without oxygen are the good models for the route here and also many of them are heat-loving so the bacteria that were discovered by the Alvin expedition are not some special branch that's adapted to an extreme environment they are the foundation we are the special branch that occurred much later but of course everything here I was talking about organisms because for organisms you can draw trees if we had talked instead about ecosystems I could have done even better because I could have answered an enormous amount with only one question where do they get their energy because if we draw the boundaries big enough every ecosystem is self-provisioning we don't live off of organic molecules from space anymore if we ever did so everything that is needed in an ecosystem is made by somebody in the ecosystem there the major division is between the ones that live from electron donors without oxygen and those that are powered ultimately by light on the surface but we learn something more kind of like Tolstoy's happy families are all alike and the unhappy ones are unhappy in their own way the reductive ecosystems are actually all essentially alike they may not be the same at the level of organisms but at the ecosystem level they're doing the same thing moreover the process of building up biomass the way these bacteria that oxidize iron and leave rust as their waste product do is essentially also present in here but it's wrapped in an energy suit where sunlight provides them what they're no longer getting from the Earth's battery so these are actually the fundamental and the deep so that leads us to a different view of the biosphere ecosystems are not merely communities they're entities in their own right the reason this matters for the origin of life is threefold first the kinds of ecosystems reductive or oxidative are not primarily determined by genetics or history they're primarily determined by metabolism second the similarity of metabolisms is evident or the universality of metabolism can be seen at the ecosystem level not necessarily at the organism level so organisms cut up a puzzle in different ways but the picture on the ecological puzzle is always the same picture here's the one that I need to argue to get you to accept it was not organisms that were the bridge from geochemistry into life it was ecosystems the division of becoming special organisms came later so now I want to make the argument for plausibility for that to understand that argument though we need to look more at metabolism because metabolism is the special property and there are clues in the structure and the energetics of metabolism that are as remarkable as anything I've showed you in the world of organisms now usually if you look at metabolism you of course instantly have a heart attack and that's because we study metabolism from the level of human physiology and medicine it's kind of like taking a beautiful telescope and looking through the wrong end and saying it all seems so far away so this is what a typical metabolic map looks like in one of the major databases but even in this chaos your eye is drawn to the order at the center of this circle what I want to show you is that this circle is in fact the knot that ties the whole thing together it does in the entire biosphere all living things and apparently has throughout all of history so this is what the core looks like a little bit closer it's called the citric acid cycle it's a cycle of 11 simple molecules the colored dots here are carbons I don't label them the smallest has only two carbons you go around to as many as six carbons that's citric acid we were all well some of us were taught in high school biology that this cycle is important it's called the Krebs cycle we were told we need it to get energy from fats and oils so that we can live that's why it's important to us but we're late and we're backward the reason the citric acid cycle is important to everything and this is stunning all molecules that you use to make the entire biosphere originate in one of four or five compounds in this cycle all the diversity that you see around you comes later but the building is all done from these now I show them to us in the form of foods because we are not ecologically complete so we know most of them in terms of the foods we need to eat to live that some plant or bacterium needs to make so this will to come to carbon compound this is vinegar and it's the starting point through which all of the oils and fats are made the three carbon compound here makes all of the sugars which are structural as well as energy molecules this one here makes the special vitamins that bind metals and that's why they have bright colors so chlorophyll and heme there are four different ones that make amino acids that are part of proteins and then from some of the amino acids we also make the nucleic acids RNA and DNA so that's how the major classes of molecules come off of this small simple core so the first apparent problem with obtaining an origin of life the problem of complexity now doesn't seem so bad but that's not the only problem we have to address there's a classic view of life as a struggle for existence the term was coined by the victorian Reverend Thomas Malthus who was worried about population and famines and Wars and this was a term that was adopted also by Darwin and was fundamental to why natural selection can work you over produce and then you call the same language permeates the sciences we talked about capturing resources or harnessing sunlight energy so the intuition is that things fall apart and that you're in the Sisyphean task of building up against the forces of decay and in the oxygenic world that's right if I take organic carbon I can put it in a furnace and it will burn and it will go back to carbon dioxide which is where it started from but in the world of vents the rules are different my colleague and friend Everett Jacques has probably put this best that instead of no such thing as a free lunch or a struggle for existence the vent world is a free lunch you're paid to eat I'll show you how what I've done here is taken the citric acid cycle compounds they're the 11 different dots for a couple of them I've drawn the molecules just so you can see where they go and on this axis I've showed how many h2 how many electrons we add per carbon to build the molecule so the sugars are two h2s per carbon the oils are three and then on this axis I've shown the energy that's used to make the molecule starting from hydrogen and co2 because hydrogen is what the vent world provides and actually what you see is this is a downhill run all the way to methane at ch4 that's our greenhouse gas so in the vent world you are not building up complexity as a struggle against the release of energy you're building up complexity because that's the path of least resistance to release energy now the reason that matters to the citric acid cycle I showed you before is that that's what drags the cycle around you can think of it as an old-fashioned waterwheel where as the water flows over it pulls the cycle around this is the same picture I'm not showing you the other clutter the hydrogen's and oxygens but I show you the same molecules and the redder a carbon atom is coloured the more oxygens it has bound to it the bluer it's coloured the more hydrogen's it has bound so you're sliding down the hill as more of your atoms become blue and fewer of them red this is the citric acid cycle in the same picture where I'm showing you each of the eleven molecules with only the carbons colored and what you can see the cycle goes in this counterclockwise direction in the vent world we run it backward the wrong way where it makes no sense but in the vent world red carbon that's carbon dioxide comes in and as it goes around it gets moved toward the interior of the molecule and electrons get added so that process of adding electrons and using the available free energy drags the cycle around in the directions that the organisms use and then that becomes the starting material out of which they build the rest of biomass I'll come back and show you this in a little bit later in a slightly different form so for now the way the earth provides a battery and the way metabolism use it shows the essential continuity between geochemistry and biochemistry that by itself would not be enough to judge whether the presence of life on Earth is surprising or inevitable to answer that question we need to do something more and that's what requires that we reconsider what we think the living state is and wait through what the right kind of formal for it is I want to argue that the way to understand the way that makes sense of the fact that life emerged on a lifeless earth and that it has persisted for almost four billion years since is the concept of breakdown or failure so remember that we're trying to understand a pattern of motion breakdown creates patterns of motion at the same time as it destroys certain patterns of structure so things don't only fall apart sometimes the events become ordered even as the structures are broken and so we have the concept that the origin of life could be a kind of collapse and once you have a collapse the idea that when pushed hard enough anything will give that brings with it the notion of necessity because in the world of breakdowns the things that persist are only the things that were the favorite state or the necessary state to begin with now this is not an exotic idea it turns out that it's around us all the time the main thing you need in order to understand it is the idea of an energy flow channel there are lots of energy flow channels in the natural world lightning is one we create a plasma that's very very very different from the surrounding dry air but it allows electricity to flow we create all this organization of wall storms in a cyclone because that transports heat from the warm oceans to the upper atmosphere and this is not the disordered pattern of just thunderstorms or uniformly mixed air so these things are well understood in the physical sciences already the thing that's important to create a channel and the reason not all things form channels is that there needs to be feedback because in all of these systems the initial stress is diffuse the clouds have a charge spread out over a great distance where the oceans are warm over an enormous volume but the ice storms constant only in one area because that moves things more so I'll illustrate for you dynamically with the simplest of all channels which is just the propagation of a fracture if you could see a fracture propagating at the atomic scale you would see that it's a self-similar repeating sequence of events as bond after bond breaks the reason this is striking is that in the original crystal there's plenty of energy in the crystal as a whole to break the bonds but the energy is too diffuse and so by itself it can't concentrate to rupture a bond the thing that causes the fracture to propagate in an orderly way instead of happening at random everywhere is that the stress field in the surround it deforms pulls the stress from the bulk back down to atomic diameters and concentrates it this is what hydrothermal vents are doing for the earth battery because the battery is accumulating over the entire atmosphere and interior but it's being focused at the regions where rock contacts water and the regions where the altered water remixes with seawater now I want to show you that this is actually what the citric acid cycle does within chemistry it performs a second kind of concentration so as the molecule goes around it pulls in carbon and then here it splits and both parts go back into the cycle so where you had one you now have two that's the mathematics of compound interest and so you can exponentially grow and you concentrate material within the cycle also like compound interest on an endowment you can pull molecules off of this to make your major classes of biological matter but the material in the cycle is still available to serve as a kind of flypaper that continues to pull carbon in over and over again so this is the second concentration now the thing this leads to an important way of thinking about the nature of life you could imagine that the optimization of this cycle was something carried out by evolution later but I think there's actually a better way to view it this cycle is self amplifying it works from the environmental sources of carbon it works from the Earth's sources of electrons and everything in the biosphere is made from it the biosphere is what you can make if these are the compounds you have and so this is why it becomes the core that organizes the whole rest of metabolism so does this give us a complete theory of origins not nearly there's a lot of work to be done there are many problems to be solved and maybe many generations maybe centuries of work before we have a satisfactory theory the way we have a theory of matter but it fundamentally changes the way we ask questions when Darwin was trying to understand the origin of the world even though he was a consummate ecologist he emphasized organisms because that was where he could say something concrete about the action selection his problem was to understand the patterns of relation the fact that some things are more similar to each other than they are to others and that was what led him to the importance of the tree of descent the idea that the degree of similarity could be understood in terms of how long ago you had a common ancestor but organisms as we said are very complicated and the tree of descent doesn't seem to do a very good job of explaining how you ever arrived at that level of complexity this is the point that Jerry raised in the introduction that what organisms are is both part of the living biosphere but they're also individual and those are two different things today we would separate the problems and I would say we asked the same question the following way we recognize that being an organism or being a virus or being a gene or being a cell in an organism is just one of many kinds of individuality and these forms of individuality almost condense like do from a kind of a background of chemical regularity and that regularity is being carried by the ecosystem but like Dew which doesn't condense everywhere the forms of individuality condense where they have paths of least resistance laid down that make it easy and so the important point about all of the concentrating mechanisms in organic chemistry the cycles and metabolism the Earth's battery these define the pads of least resistance so we can come finally back to the question of chance and necessity there are two sort of classic pronouncements each made by a major and truly great scientist that reflect exactly opposite points of view Jacques Monod worked on bacterial regulation and was one of the discoverers of how this works his view from all of the complexity of genetics and genomics was that life could be understood in terms of scientific principles but there was no hope of predicting he envisioned the trajectory of the biosphere through history as a kind of a random walk where even the major steps could not have been foreseen Christian de Duve took exactly the opposite point of view in a way that's very subtle and I think it's missed by many people to have recognized of course that the Assembly of a modern cell would only be possible with selection because there are so many choices they have to be selected at each range but he went on to say something more delicate he said even the problem of producing the choices that selection can act on is so complicated it's very difficult to understand how that could happen in a process where everything is equally probable and this was what led him to propose that the success of the evolutionary game as he puts it was written into the fabric of the universe what I've wanted to show you in the earlier parts of this talk is where in chemistry and in the properties of our planet those choices were laid down so I have many people that I need to thank for this I absolutely want to thank Jerry not only for the privilege of giving you this talk but for supporting my work and the work of my collaborators for more than a decade I want to thank a friend William Melton who supported us through the last two years in which this book was brought to completion and Jerry also supported me during that time of course the National Science Foundation for bringing the community together and the three places yeah most importantly Santa Fe Institute that we're home for so many years yes please know the oxygen is being left behind I should stand where I'm expected the oxygen is being left behind so what you're doing is you're losing oceans but you're only losing the hydrogen part of the oceans good yes but are we are we also gaining anything from the solar wind uh some but probably not a lot um we're not gaining water we might I know it's a great question um I don't know what the gain of the rate of gain of hydrogen is from the solar wind quantitatively I know it's less than the rate of loss but I don't know by an order of magnitude how much less thank you good hmm in the back yes please so you're likely familiar with the debates on whether viruses are considered alive or not I imagine at least I've heard of cases where a virus can be as simple as just of replicating molecule like RNA or DNA surrounded by a protein coat not doing anything like metabolism so do you think that means it is not alive great yeah lovely question I'm going to answer that by saying that the whole question turns out to use a form of English that's not meaningful in the following sense so here's here's a little bit of logical semantics work with me and tell me if this works for you if I use the term living thing a thing is a noun living is a predicate right what that means is I imagine that I can take the whole world of things which are fundamental and I can divide them into two sets the living ones and the nonliving ones but if things are not fundamental and if life is not a property inherent in things then the whole notion living thing is a set of words they satisfy the rules of syntax but it's not clear they actually mean anything so what happens if the property of being live is defined by participating in the order of the biosphere all the things that build it up all those that break it down and what we're seeing in cells and viruses is a form of individuality now I say is a virus one of the forms of individuality in its lifecycle when it's just RNA and a code absolutely and we can talk scientifically about what's special about that form what makes it different from a cell but I don't ever ask the question is the virus alive or not because the virus is part of the biosphere and it partakes of the character of the living State from the biosphere as a whole so that's a little bit heavy as a way to answer a very good question but I think it's the answer that will stand the test of time I'll come right back to you yes I've read there are some you know the Big Bang at the beginning of that kind of life that were preceded it was a consciousness or the idea for the universe to grow so could you apply that to what you're talking about here that there was a consciousness that helps to move this or create the origins of life and create you know a place for that life to grow that's not a language I have the ability to use in any comfortable way in the know in a very particular sense right I could say that once a snowflake is formed like commonplace processes we can talk about aspects of the pattern that makes one snowflake different from another and in a similar sense I can go through the emergence of life on a planet and then organisms and then nervous systems and somewhere Late Late Late I have these incredibly complicated patterns that we just barely understand and for me its natural to look for consciousness as a character of patterns at that late level but in the same sense as I would not ask whether something about the snowflake was before the properties of water because it seems to be at the wrong end I'm not able to use a language that puts consciousness at the low level as a form of non-physical energy we've talked a lot about physical energies but we don't talk about non-physical energies and consciousness could be considered if it's thought of that way then it predates everything doesn't come after the snowflake comes before the snowflake no you know anyway I just wonder if these kind of the sciences don't all kind of talk with each other and I think there's some ways where they can where there is an interdisciplinary study there I'm just questioning I think it's wonderful that you asked I think it's a right conversation to have I think it's very hard to talk and to listen both and I will admit that my view is pretty much a mechanic's view of a great many things and perhaps that limits the set of things I can say well I think you have largely answer to the question I was going to ask and it is a deed the AIA the idea I understand how you followed this path of potala lism of energy into living forms as a necessity and and how you how it comes to be and that that hypothesis is is new to me but I'm missing the same thing the difference between the rock and organic and inorganic inorganic carbon and carbon whether or not what we've always called the lifecycle of the carbon cycle the things you learn in chemistry I was the particular properties that tell us whether or not the energy is living or nonliving in that whole origin and metabolism have you given any thought to that I think you've already answered it the last thing you said but what are your own thoughts about that and you have any idea of using the scientific method to try to discern that good so that has some words in it that I can't address because I know how to use them carefully the notion of energy is one that we have struggled tremendously to get clear for the last 250 years and one of the great triumphs I think of a unification in science is that energy is energy and so it's precisely because the role of energy in the nonliving world and in the living world is the same role that we can understand how the living world embeds in living world and so that's not a place where I think it's correct to look for differences I think humans are great at when they haven't seen something imagining something different from the truth pads of least resistance and failure modes are incredibly complicated and we've only figured out a few of them I think there's huge scientific mileage in learning how to do that in the dominance of dynamics and of chemistry where we're just babies we've only begun to form science in those domains does every hydrothermal vent have life associated with it and are the chemistry's the same across all those different vents so they've all been created to novo but all been the same superb question um yes no and no um no if if I could give you an hour-long talk on only this one subject in a university department the things I would tell you so first thing to realize there is no place we have ever drilled dived or flown in the earth that we have not found life which is one of the reasons it's so hard to understand origin because everything has been colonized by somebody modern so not only does every vent have life in it every mineshaft hole has life in it everything that gets blown up from the subsurface and a volcano winds up having life in it so there's life everywhere there is certainly life that is uniquely hosted by the energy at vents but your next question is wonderfully perceptive because it is not all the same the vent chemistry is not all the same and the life that they host tracks that vent chemistry quite in detail so the vents that I showed you are the charismatic ones let me give you two line thing about geology I told you that the deep rock in the earth has mostly this iron to plus character to it when it comes up it gets oxidized that's the process of converting what's called mantle into crust normally you don't see mantle on the surface you only see crust on the surface and the Magma's that make crust when they interact with water they create these black smokers that are full of metals and they have very acidic pH 2 or 3 in rare cases you can actually get some of the material that's supposed to be protected down below exposed on the surface it can be stripped off by faulting the picture I showed you of the lithosphere is Oman it's a place where continent formation actually causes to be shoved up on the surface of dry land in those areas it turns out you do not produce acidic vents you produce alkaline vents and you produce enormous amounts of hydrogen if I showed you the undersea version of those they do not have black smoke because without acid they don't dissolve metals they don't dissolve sulfide instead they're white and shimmery and they produce carbonate chimneys in today's oceans if you looked at those you would not find tubeworms you would not find crabs or snails or clams or shrimp you would find only bacteria and archaea so would be a very dull picture compared to the one I showed you but its enormous ly important because it turns out I think the reason and there's so many things I didn't tell you about even the black smoker world in spite of the fact that they live on a tiny energy budget far from the Sun those two worms are actually the fastest grown organisms known they that's the fastest production of biomass of any known system and I think the reason for that is that we need metals to live and that's what those vents are producing in profusion without the metals you go into a much sort of more miserly mode of life where only the most conservative bacteria and archaea can make it but thank you Green and we have a couple people here on the site too yes do you what do you think of the theory of panspermia as the cause of life and could you define it for the audience yes with pleasure good so panspermia was the idea that in the non polemical form life may not have originated on earth it may have originated somewhere else and been transported to earth now the polemical form it's really hard to understand how life originated on earth and we only had four and a half billion years to do it the universe is 13 billion years old so that's more than a factor of 2 maybe if we had the whole universe we'd have more time now that was the old-fashioned version sort of a 1970s version there are more modern and more sophisticated versions where people say that some of the things about the Tron battery that I showed you are actually stronger on Mars than they are on earth and some of the properties of water may have been easier early on those are very technical arguments on I don't know how to evaluate them I consider those to be the most plausible arguments that there could be important chemistry relevant to the origin of life that could be on a planet other than our own where the life evolved to some significant degree of complexity and was then transported here for my own preference I regard those with suspicion because I think when we find something difficult we probably say oh that must mean it's impossible and our understanding is too primitive to draw a conclusion like that at this point we understand how hard it is to make life on Earth precisely because we understand the chemistry of life on Earth so well and so is it sensible to go someplace where we understand the chemistry less well where we have to rely on transport through space to deliver but then here's the most important thing if you think my argument has any validity that we should look at life as a breakdown process so that only the only things that persist are the things that were the native state anyway and you just had to get to them if life on Earth was not the native state to get into and it was a more native state somewhere else then why would it have been a robust thing to build it there and transport it here why would it have survived here for four billion years without interruption if it was not a thing that would natively form here now that's not strong enough to be a science argument and I understand sweetness but that direction is the drift of my not worrying a lot about pence per Meah do you agree to the theories of George Wald who said that life came from an electric strike like lightning that hit the elements the Earth's primordial atmosphere and life evolved from that those experiments where amino acids devolved into proteins and life form do agree with those theories I would not repeat them in the way their original investigators believed them to be true um again to speak a little bit carefully lightning strikes turn out to matter on earth because they do something very difficult they take n2 which is a very strong molecule and they break it up into the forms of nitrogen that wind up being chemically interesting that may matter but I think it only matters at the scale of the whole planetary dynamic the chemistry of the atmospheres is extremely different from the chemistry of life you remember I said that chemistry and water is very restrictive and there are a lot of things that you can't do with it the chemistry of carbon and of metals in the deep subsurface is incredibly similar to our biochemistry so much so that you can look at enzymes that use metals and they use them as if they had just taken a mineral center and learned how to harness it for certain types of jobs those things were not known when George Wald was writing these things and I think a lot of the opinions you're talking about come more from Stanley Miller and the followers of Stanley Miller up after 1953 his experiments were groundbreaking but there are two things two ways you can interpret them one you could suppose that those experiments were good models for the origin of life that I think doesn't hold up so well now though there are still many people who disagree with me but what you could say instead is if chemistry and the atmosphere that's so different from biochemistry led to amino acids many of which are the same as those in biochemistry what should we be learning about the paths of least resistance in organic chemistry that can cause very different starting points to collapse into a few paths and then kind of like trees growing along the waterways in the desert does biochemistry use the chemicals it does because it's following those paths of least resistance even if we learned about them in the wrong environment and there's somebody who really wants to ask another question and I don't want to cut him off okay so you will be the last one you've had your hand up there where Oh no I'm almost embarrassed to stand up considering the quality of all the questions here but as a practical matter we are so familiar with the term climate change and what's happening in climate change is is mankind doing anything relative to climate change that would affect your theories in any way shape or form or is they two completely different subjects I'm so glad that you got a chance to ask because it would have been ashamed not to hear I don't think that the things that people are doing affect the theories but I would like this work to affect the things that people do so this was the point that Jerry opened with in biology too much we have put ecosystem sensibility kind of in the periphery and we focused on organisms and when we interact with a natural world whether we do it industrially or agronomically we try to engineer organisms and we try to we try to influence systems with a few components as if we were building a watch or a bridge and routinely it winds up putting us in places where we don't want to be or what we shouldn't want to be if biology can anchor ecology more centrally and start to understand the regression of ecosystems toward certain patterns that it's very hard to pull them away from maybe biology can help us head off misunderstandings in the world of application and make us a little bit more intelligent or in some cases a little bit more precautionary about what we do biology as a science is sound but biology as a science is not always proactive enough to miss to anticipate the mistakes people are going to make a more ecological biology may prime us to be a little bit better at second guessing the things that can go wrong and trying to be careful ahead of time you

Channel: The Aspen Institute

Views: 73,251

Rating: 4.6544714 out of 5

Keywords: Eric Smith (TV Personality), origin of life, Aspen Institute (Nonprofit Organization), Biology (Media Genre), Life (Quotation Subject), Colorado, Darwinism (Literature Subject), evolution, Santa Fe Institute (Nonprofit Organization), String Theory (TV Subject), Biology (Composition), Fourth Geosphere, Ecology (Media Genre), Dr. Eric Smith, science, Charles Darwin (Academic), Theory (Quotation Subject)

Id: 0cwvj0XBKlE

Length: 65min 55sec (3955 seconds)

Published: Fri Jul 10 2015

Reddit Comments

[u/hsfrey]

Fascinating insight!

It makes the existence of extra-terrestrial life much more probable if the construction of the building blocks is exothermic in any earth-like planet.

[u/Alchoholocaustic]

Can someone ELI5 how he's so confident self regulating citric acid cycles existed before life? I think a lot of his evidence went over my head.

[u/ragica]

Reminded me of many elements of Gaia hypothesis, taken a bit further (and looked at from a different direction). I wish someone had asked about how his views sync with and/or differ from that in the Q&A.

Here's his book mentioned in the talk, The Origin and Nature of Life on Earth: The Emergence of the Fourth Geosphere (with a seemingly unrelated Eric Smith goodreads author bio beside it). I've just been looking through it, and he does reference Gaia in a footnote on page 42, in a section called "Ecosystems are not super-organisms". The conclusion there being:

"In our view, the correct response is not to shoe-horn ecosystems into a strained analogy with organisms, but to grant them their own status as entities that carry patterns essential to the living state, and to develop a language and theory of the ecological level of organization"

Which almost begins to sound like an argument of semantics, or even philosophy. Though his perspective is certainly legitimately different in its intent, and so I can see why he would want to separate himself fairly sharply from Gaia as a concept.

[u/Silvernostrils]

This is science philosophy

and the fuzzy concept of "patterns of life" being part of the fabric of the universe sounds like new age mysticism.