College and the Graduate Center of the City University of New York and this is exploration every week on exploration we discuss the fascinating world of science and packed on society and today we have 2 very special guests because we are celebrating the 150th anniversary of the most incendiary blasphemous controversial theory of all time i theory which still makes headlines around the world a theory called evolution it was 150 years ago that Charles Darwin wrote Origin of Species and set off a bombshell that reverberates even today so our 1st special guest on exploration is Dr Robert Hagen he is an astrobiologist he looks for evolution not on the earth but in outer space and the question that we're going to ask today is is it possible to bring a bunch of chemicals together to create the basic ingredients for life is life in some sense for free this had happened all by itself spontaneously in outer space according to the laws of chemistry and the laws of physics Dr Robert Hagen is an astrobiologist at the Carnegie Institution in Washington d.c. And he's the author of a new book called Genesis talking about the search for life in outer space and how many scientists believe that life may form spontaneously literally all by itself if you break the right chemicals in the right conditions together and then in the 2nd half of exploration we're going to talk about the most controversial the most incendiary aspect of Charles Darwin's theory and that is the application to human beings when Charles Darwin wrote The Descent of Man arguing that humans a standard from a common apelike ancestor. Well everything hit the fan at that point everyone from religious people to the man on the street to learnit observers and even scientists began to denounce Charles Darwin saying that this was all blasphemous saying that this contradicted the Bible Well Charles Darwin simply presented evidence but luminous amounts of evidence and data a lot of it incomplete of course but sufficient data to convince many biologists that Charles Darwin was really on to something and fact many biologists including the famous Thomas Huxley said gee why didn't I think of that is such a simple idea survival of the fittest natural selection plants and animals evolved with time and certain characteristics are extension weighted because of natural selection and they were all descended from a common ancestor of such a simple idea said many people and of course is no accident that even today even today the theory of evolution is the now and by fundamentalists because it does violate many of their teachings so once again the 1st special guest is 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 as 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. And 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 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 wall 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 Go Pro football is really small but I got larger and larger telescopes that end up building my own by 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 had a teacher who pointed me in the direction they go to Franklin New Jersey go to Patterson New Jersey collecting mineral 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 asked. Biology Oh astrobiology is one of the most amazing new integrated fields in funny and 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 NAFTA and announced that Astrobiology Institute which is based at the Ames Research Center in California. Ok so your book is entitled The 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 advice or 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 what Professor what a transformation at what Stanley Miller young 23 year old graduate student at the University of Chicago has a mentor with Harold Yuri who had won the Nobel Prize for the discovery of do you teary I'm happy hydrogen isotope of heavy water so you're with incredibly famous Miller with an unknown never came to your eon 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 electric spark through a piece of glassware and lo and behold in just 2 or 3 day is that clear colorless dilution began turning shades of pink and then Brown and then black gunk started getting deposited on the side of the class where Miller had made a whole range of organic molecules that were basic building blocks of life the needle acids to make up proteins the sugars that make up a hydrates all sorts of molecules that form cell membranes called Lippitt and not only that a few of the bases they're called these 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 sparks like lightning Ok so let's back up a bit we're talking about is getting a flask with horrible chemicals like ammonia methane hydrate. Them sending a spark through what 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 and you know 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 this is a 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 all these building blocks of life then given millions of years the early ocean would just have been chock a block full. Of organic molecules and that was what led to this idea of the primordial soup and early. Just the right building blocks for life to people but 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 was a little overly optimistic that they kind of a lot longer and we're still a long way from knowing but this was the 1st experiment the seminal experiment that got us 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 ammonia 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 looked like back then well the one thing about the atmosphere is that Yuri I do. Yeah of an atmosphere of hydrogen and methane is much to what's called rate 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 too well perhaps other might or components like carbon monoxide maybe a little bit of methane maybe some hydrogen but not as chemically reactive as the atmosphere that Miller proposed Nevertheless when you put shock spikes through any of those atmospheres 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. Oh Ok No 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 Maurice fame back in the 1950 s. It was also used to investigate what are called Volcano vents and some people say that perhaps volcano events is where life got 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 it requires water some kind of water rich environment it involved it requires energy of some kind now you know said lightning other people say from light but you also have the energy from the earth in your heat and you require carbon and other carbon based compounds that are called organic molecules turns out one of the most exciting environments on Earth where all 3 of those ingredients come together are the deep ocean and then the hydrothermal vents are the plaques smokers as they're sometimes called on the bottom of the ocean and these were discovered in the late 1970 s. By just by fighters diving in the foot most about how I've been off the Pacific coast completely unexpected to find not just these hydrothermal vents under the smokers if you will with all sorts of mineral rich hot fluids coming up but the final living community far 5 below the influence of the front where it's totally dark all the time and you know life thrives 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 gets our 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 tied . You know about creating life from nothing almost So you're saying essentially that the energy supply could have been this very caustic environment on the bottom of the ocean that's the theory and here's why people think that might be so in our body of the energy for example from plants or from sunlight it's kind of heard it through a profit it's called oxidation reduction reactions either reaction just like it occur in a batter your flashlight battery you're basically transferring electron the from one group of chemicals to another and that exact same process the Kurds deep on the ocean floor because very what are called reducing fluids to come out from the you lower the ocean surface and they get very oxidising water in the ocean and that couple the oxidation of the reduction together causes chemical reactions just like in a battery just like in your body that's what we'd think the very 1st energy for life was just like a battery trip in by the 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 in the movie 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. Fingo life gets started very soon so he says this means that life could not have started on the earth it 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 well at 1st glance it sounds like a pretty crackpot idea you know like being seated from outer space but a lot of Spite of star 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 say life for Russia comes about in a 1000000 years 1000 years there's one very famous scientist in the field of human thought that takes 2 weeks Well that's true in life 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 would have it won't be long before Earth much less in the way of bombardment by meteorites much more up and 9 in terms of its temperature early on and if out of oceans there lakes we know no doubt from these recent discoveries by now that the Mars was a bit of all hundreds of millions of years before Earth it's very possible that life arose on Mars and then there's this amazing mechanism if Mars gets hit by a mine outright there's something that 10 or 20 or 30 kilometers across. There 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 modern meteorites. Whole group of scientists that are giving very serious consideration to the idea that all life on earth 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 may find Earth like right off awful like Life On Mars to represent i ancestors so if you want to see a martian you should simply look in a mirror up to possible 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 rearranged in different ways of course but there's only one d.n.a. It has a t.c.g. As the building blocks of 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 don't 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 now 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. He's brighter but you know that's such a great question and a lot of us are asking the question this way is the chemistry that we see in life today inevitable or I don't walk the alternative way well after all turn of phrase why don't we see him and the explanation that's most often given if it were right for 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 that cell got started but if I did enough flash heat on microbes can divide it in less than an hour he had one then 2 then 4 then 8 and in a matter of weeks. It was populated by doubt extremely successful self replicating cell and that fell ate everything else you didn't have a chance if you weren't the 1st on the block to know how to live and know how to reproduce then you were going to get eaten because you were food Well let me ask a question that 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 may be 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. Gee the 4 nucleic acids but it's based on a different set you know up. Hardesty or whatever and it creates proteins that are under just double by ourselves and therefore the 2 life forms should co-exist but if it's well I think honestly that life has been very careful in the molecules it's the lack for example r.n.a. Uses right both d.n.a. Used to be on the right but by goes particular sugars these are sugars with 5 carbon atoms and there are dozens of different sugars with 5 carbon atoms why those turns out there's actually a kind of vantage to those molecules because of their 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 life uses are the best molecules for the job 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 of anything and it's environment that has energy life has learned to eat but I think it's just once you get one kind of life it 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 the best computer and other companies try to get started but if that 1st company of those huge and so large it just swallowed up the competition and nothing else to get going so like the diamond monopoly have to be yours you know there's never been another big company making diamonds because to be your eyes 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 is that what you're saying I think it's possible that some aspect that by chemistry 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 2 sets of 3 chain addict letters 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 on how their world did it would be 5 very different from ours so I can't imagine there being that kind of unity so there are some a chance of in some chance a chemical event and the origin of life but I think there are also some aspects of origin that are going to be very si