Well guess as Dr Robert Hagen astrobiologist at the Carnegie Institution and author of the book Genesis talking about the genesis of life in outer space and the 2nd special guest talk about the most incendiary aspect of the evolutionary theory the application to you and me our special guest is Carl Zimmer biologist author of the book Evolution talking about how humans humans probably evolved from a common ape like ancestor according to the fossil evidence and also the voluminous evidence given to us by d n a and biotechnology so an exploration today we talk about evolution and out of space and evolution of our own bodies. Well our 1st special guest today is Dr Robert Hagen of the Carnegie Institution outside Washington d.c. He's an astrobiologist author of the new book Genesis and we are talking about how the 1st spark of life began on the planet Earth about 3 and a half 1000000000 years ago. The 1st question for you is how did you 1st get interested in science as a youth Oh man I would so excited about nature when I was young we had a house in Cleveland Ohio the back onto a swamp and my brother and I would go tramping back we collect butterflies and we collect frogs and we collect crayfish and at night I love looking up at the sky and the stars and so my parents bought me a telescope and this was really small but I got what your larger telescopes that end up building my own but love looking at the sky and looking Saturn with my favorite nature just turned me on when I was in high school I moved to northern New Jersey and northern New Jersey is just a gold mine for mineral their famous Mineral County and I got out teacher who pointed me in the directions that go to Franklin New Jersey go to Patterson New Jersey collecting minerals and that's what really got me into mineralogy which is my main field right through college Ok now you are an expert in an area that is not familiar to the average person and that is something called astrobiology So what is astrobiology Oh that's right biology is one of the most amazing new integrated fields in finance it's the study of the origin of life the distribution of life in the universe and also discusses what the future of life might be in the universe this is a field that has been brought to life by major new funding through NASA and announced Astrobiology Institute which is based at the Ames Research Center in California. Ok so your book is entitled genesis of the scientific quest for life's origin Let's begin now in the year 953 with an experiment done by a graduate student under the direction of his advisor by the name of Stanley Miller could you tell us a little about that experiment and how that led to a paradigm shift with regards to how we view Genesis but Professor what a transformation at what Stanley Miller young 23 year old graduate student at the University of Chicago did mentor it with Harold Yuri who had won the Nobel Prize for the Discovery up to tear him to be hydrogen isotope of heavy water so you know he was incredibly famous Miller well known you know what came to your Ian said I want to try and experiment to make the molecules of life from nothing more than a primitive atmosphere now you had proposed the primitive atmosphere consisted of hydrogen methane which is the natural gas you burn on your stove and ammonia that's the strong smelling chemical from ammonia cleaners and you mix those together with water and just ran a lector box through a piece of glassware and lo and behold in just 2 or 3 day is that clear colorless the Lucian began turning shades of pink and then Brown and then black gunk started getting deposited on the side of the glass where Miller had made a whole range of organic molecules that were basic building blocks of life mean acid to make up protein sugars that make up the hydrates of all sorts of molecules that form cell membranes called limpid and not only that a few cases they're called these are the molecules that are key components of d.n.a. And r.n.a. Many of the most fundamental building blocks of life just appeared out of a simple primitive atmosphere and looks like lightning Ok so let's back up a bit over talking about is getting a flask with horrible chemicals like ammonia methane hydrate. Him sending a spark through it essentially replicating what they thought was the early atmosphere of the earth bombarded by x. Rays and lightning bolts and so on and so far and bingo out of that came the building blocks of proteins amino acids so what was the reaction of the scientific community which before that experiment was really. Basically had no theory as to how organic chemicals could form out of nothing it's true that the bombshell the scientific community looked at this and thought Wow this must be how life originated in just a couple of days you can go from a simple atmosphere to the building blocks of life then given millions of years the early ocean we're just going chock a block then. That working out of molecules and that was what led to this idea of the primordial soup An early. Just the right building block for life that people thought she it's going to be a matter of 10 or 20 years they will know everything there is to know about the origin of life that's a little overly optimistic and taken with a lot longer and we're still a long way from knowing but this was the 1st experiment that that little experiment on the path to believing that there is a chemical origin of life going from the simplicity of a geochemical world to the complexity of the biochemical world Ok so back in the fifty's they thought that the early atmosphere of the earth was a hostile brew of ammonium methane hydrogen and things like that however today we're not so sure today many groups have proposed a different scenario for the formation of life on the earth very similar of course to what Miller and you're a had but with a different chemical composition of the soup what is now the leading theory as to what the atmosphere in the oceans look like back then well one thing about the atmosphere is that yeah I do. Yeah of an atmosphere of hydrogen and methane is much to what's called me do you think we'd think that it was a much more chemically neutral atmosphere including things like nitrogen that dye nitrogen gas that makes them of the right atmosphere today perhaps them feel to perhaps other might or components like carbon monoxide maybe a little bit of methane maybe from hydrogen but not as to make way reactive and the atmosphere that Miller proposed Nevertheless when you put Shop Fox through any of those that matures you still get very interesting products for the basic concept of the miller your experiment is certainly valid but there are other environments as you suggest. Ok now I'm the Alvin submarine which was used to probe the Titanic writing on the bottom of the ocean and also to retrieve the hydrogen bomb dropped off the coast Apollo Marise Payne back in the 1950 s. Was also used to investigate what are called Volcano vents and some people say that perhaps a volcano events is where life started it's one theory but could you elaborate on that theory yeah the idea here is that life requires a couple of simple ingredients requires water some kind of water rich environment it involved it requires energy of some kind no Miller said lightning other people think about light but you also have the energy from the earth and you require carbon and other carbon compounds that are called organic molecules one of the most exciting environments on Earth 3 of those ingredients come together are the deep ocean and the hydrothermal vents or the plaque smokers as they're sometimes called on the bottom of the ocean and these were discovered in the late 1970 s. But right now it is diving in the submersible how it went off the Pacific coast completely unexpected to find not just the hydrothermal vents be under the smokers if you will with all sorts of mineral rich hot fluids coming up but the final living community far right below the influence of the front where it's totally dark all the time and you know life right because of all that energy coming out of the ocean floor now when we talk about energy we realize that we mammals get our energy by eating plants so we mammals could not have been the 1st form of life on the earth but plants in turn get their energy from sunlight in a very complicated process come full photosynthesis which also could not have been the original energy generating device because it's very complicated and we're time . You know about creating life from nothing almost So you're saying essentially that the energy supply could have been obvious very caustic environment on the bottom of the ocean that's the theory and here's why people think that might be though in our body the energy for example from plants or from sunlight is kind of routed through a process that's called oxidation reduction reaction to their reaction just like it occurred in a batter your flashlight battery you're basically transferring electronics from one group of chemicals to another and that exact same problem that's occurred deep on the ocean floor because very what are called reducing the fluids to come out from that if you lower the ocean surface and they get very oxidising water in the ocean and that the oxidation in the reduction together causes chemical reactions just like in a battery just like in your body that's what we think the very 1st energy for life was just like a battery trip invited to earth. Ok now the astronomer Fred Hoyle had a different theory in fact he was quite the contrary and within cosmological circles and he said the following that the Earth is 4 and a half 1000000000 years old roughly speaking and during the 1st 1000000000 years was the age of asteroids and meteors constant bombardment by debris from outer space for about a 1000000000 years we see that on the moon even today and as a consequence if life formed in the oceans the oceans would have boiled off and therefore life could not have gotten started within the 1st 1000000000 years or so after the age of meteors ends. Pingo life gets started very soon so he says this means that life could not have started on the earth they came from outer space in the form of spores so he called this the panspermia theory but what do you thoughts about the panspermia theory at 1st glance that sounds like a pretty crackpot idea you know why it's being heated from outer space but a lot of Spite of they're now taking this very seriously I think there are 2 possibilities one is that life is a cosmic imperative it arises everywhere and it arises very quickly I put scientists they like to write comes about in a 1000000 years 1000 years there's one very famous writer in the field even the takes 2 weeks Well that's true in light but of reason on earth and there's no problem but if life does take hundreds of millions of years we have a planetary neighbor Mars that was applicable long before Earth much less in the way of bombardment by meteorites much more open I mean in terms of its temperature early on and if out there like we now know that from these recent discoveries by now the miners with Abbottabad hundreds of millions of years before it's very possible that life arose on Mars and then there's this amazing mechanism if mind gets hit by asteroid something that 10 or 20 or 30 kilometers across. Will be it's been shown Don't be rocks thrown up into space and those rocks would be relatively unheated relatively unstressed they could contain microbes and those microbes could then be brought to Earth by meteorite. A group of scientists that are giving very serious consideration to the idea that one. Is Mars life because Mars was habitable earlier and we may know that if in the next decade or 2 when we go to Mars and we look specifically for life we might find life right fossils like Life On Mars that represent I answered so if you want to see a martian you should simply look in the mirror. Now let me ask you a question that's bothered me for a long time and that is the Earth is roughly 4500000000 years old but there's only one d.n.a. Molecule rearrange in different ways of course but there's only one d.n.a. It has a t.c.g. As the building blocks nucleic acids that's why we can eat anything on the earth we can eat sea urchins we can eat insects we can eat plants even though we're separated by a tremendous evolutionary distance because we're all made out of the same molecule Now if there's 4 and a half 1000000000 years old. And life gets started pretty quickly that how come it didn't start again with another d.n.a. And again and again why do we see different d.n.a. If we only see a t c g we only see a certain set of amino acids and that's it we've had not just a few 100000000 years we've had 3 and a half 1000000000 years of quiet oceans with no meteor impacts to speak of so why don't we have many d.n.a. Like robots you know that's such a great question that a lot of us are asking the question of why is the chemistry that we see in life today and evitable Well I don't watch the alternative way well. Why don't we you know the explanation that's most often given is why put the competition and once that 1st successful self replicating cell with all of its proteins and d.n.a. That failure fission very powerful mechanism once we got started but if I did enough you know microbes can divide that our field one and 2 then went on 8 and in a matter of weeks the earth was populated by that extremely successful self replicating well and that's ate everything out you don't have a chance if you want the 1st on the block to know how to live and know how to reproduce then you are going to get eaten because you are food Well let me ask the question then food depends on proteins proteins in turn depend upon a template that is d.n.a. Template to create the protein but there are many proteins that nature has not used there are many proteins that you can create that nature is not even thought of so why didn't another d.n.a. Get off the ground that was uneatable unedible that it was based on proteins that simply cannot be digested by our d.n.a. And it's not based on a.t.c. G 4 nucleic acids but it's based on a different sat you know. Hardesty or whatever and it creates proteins that are undigestible by our cells and therefore the 2 life forms should co-exist but if it's well I think partly that life has been very tough on the bollock you'll elect for example I may use the right both d.n.a. Used to be on the right but I don't particular sugars either sugars with 5 crap out of and there are dozens of different sugars with 5 coming out why those turns out there's actually a an advantage to those molecules because a particular shape and people are shown that if you try to use other molecules they don't work so to a certain extent the molecules that white you are the best molecules for the chalk but also I think life is incredibly good at taking various other potential molecules and eating them it's just amazing how life is used all different kinds and you think that if environment that has energy life has learned to eat but I think it's just what you get one kind of life and stablished it's really hard to get a 2nd competitive system going it's sort of like the ultimate monopoly you know you can imagine some company makes the best car of the best computer and other companies try to get started but if that 1st company is so huge and so large it just swallowed up the competition and nothing else we got going sort of like the diamond monopoly have to be or you know there's never been another big company making diamonds because the pure write them all up and swallowed up the competition Well the reason I ask you this is because in science fiction movies we always see aliens from outer space that want some very specific things 1st of all they want to eat us meaning that they can digest our proteins which I find remarkable 2nd of all they don't want to mate with us in which case they have basically the same d.n.a. As us literally so they can interchange d.n.a. Sequences with us and I find this rather impossible but what you're saying is that in some sense d.n.a. Really is preferable and that. Maybe when aliens from outer space land on the earth they're going to have d.n.a. Which is very similar to ours you know what you're saying I think it's possible that some aspect of biochemistry will be very very similar maybe even d.n.a. R.n.a. But I think there will be very important differences but one thing we have what's called the genetic code and that basically are that the reach an addict letter that match up to different amino acids the building blocks the protein I think that code may be wildly different if even if there is a code of their world that it would be but very different from ours so I can't imagine there being that kind of unity but there are some a chance of in some chance a chemical event and the origin of life I think there are also some aspects of origin that are going to be very similar for world the world Ok well if you say that if another d.n.a. Got I think around in our d.n.a. B.c. Ate up that d.n.a. And then what happens when Alien d.n.a. Reaches the earth will our d.n.a. Consume molecule for molecule their d.n.a. Or vice versa perhaps their d.n.a. Will consume ours Well it's a really good question it depends on the building block molecules I can imagine alien d.n.a. I can imagine alien proteins that are totally poisonous to us and vice versa it's also very possible that life on other worlds started with an opposite and there is a very curious characteristic of life on Earth that the sugar molecules used in d.n.a. And r.n.a. Are called right handed and the amino acid used in proteins I want to call left handed mirror image molecules that I body used in fact that's what it for dieting there's a new product out you can buy left handed sugars which treats sweet but the body can't digest them so this is one kind of artificial sweetener which gives you no calories it's a great invention it's a great idea so if there were an alien life form that happened to be reversed and they used less kind of sugar. And right handed I mean that they could need we could need them I think we'd probably get along Ok now let's get back to the Miller experiment because there's a huge gap that we have left unfilled Miller show that I mean no masses in some sense are for free we see them in nebulous in outer space we see them in the cores of meteors from outer space I mean no acids are out there you know to space however d.n.a. Is extremely complicated if you look at a d.n.a. Molecule you say to yourself My God look at that thing and it would have taken an awful long time if for Miller to get a d.n.a. Molecule off the ground if he had done his experiment for maybe a 1000000000 years in that little test tube that maybe he would have gotten one d.n.a. Molecule off the ground so there's missing steps now so some people say that before d.n.a. There was already a before or and a there was a even more primitive structures even before r.n.a. So what do we know about the gap between the amino acids that are for free that we see in the Miller experiment and r.n.a. And d.n.a. This is probably the single biggest uncertainty in question but there's so many great ideas out there for one thing as you say I know a. Very complicated molecule and it's hard to imagine how it was that the finest from scratch in the people out of the middle step of that may have helped the minerals that attract right there's the minerals that are attracted to. Out there in the Genesis I described an experiment by a person at our laboratory guy named Nick Lachey who realized that you could build up an r.n.a. Like molecule from very very simple building blocks little like what all molecules the kind of things that are produced when you know it's not. When you talk about so the fire that you know. If you