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Science

Primordial Soup: Interview with Stanley Miller 564

An anonymous reader writes "Stanley Miller's classic 'primordial soup' experiments showed that 13 of the 21 amino acids necessary for life could be made in a glass flask. For its fifty-year commemoration, Miller is interviewed today and reflects on what Carl Sagan called 'the single most significant step in convincing many scientists that life is likely to be abundant in the cosmos.'"
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Primordial Soup: Interview with Stanley Miller

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  • Land Sharks (Score:5, Funny)

    by Scoria ( 264473 ) * <{slashmail} {at} {initialized.org}> on Wednesday May 14, 2003 @09:51AM (#5954149) Homepage
    showed that 13 of the 21 amino acids necessary for life could be made in a glass flask

    Of course, certain products of his experiments often indicate that not all of them are necessary. These products are, of course, "intellectual property lawyers." :-)
  • by Saint Aardvark ( 159009 ) * on Wednesday May 14, 2003 @09:52AM (#5954161) Homepage Journal
    I tried duplicating Miller's experiment in my last year of high school for my chemistry final project. I didn't have a way of zapping the gases, so I tried shining a UV lamp on them; I'd read about different versions of the experiment that had tried that with success. And I didn't have a way of evaporating and condensing the liquids, so I just poured 'em into a big jar and hoped the interface between liquid and gas, combined with whatever UV light made it through the glass, would make amino acids. And I didn't have a gas chromatograph, so I had to use a chemical...damn, don't remember what it was, but it turned purple in the presence of amino acids and is used to detect fingerprints on paper.

    It hardly needs saying, but in a week I didn't make any amino acids I could detect. Nevertheless, I ended up getting a shockingly high mark because I'd written up every possible reason I could think of for the experiment failing: not enough time, not enough interaction between liquid and gas, not enough energy from the light, test wasn't sensitive enough, Miller had faked his results (ha!), etc. I was disappointed in the results, but pretty happy with my mark. :-)

    • by laughing_badger ( 628416 ) on Wednesday May 14, 2003 @10:17AM (#5954372) Homepage
      It really shouldn't be a shock that you recieved a high mark.

      Education should provoke thought. Just training kids to pass tests is of no value. What you did, analysing your results and thinking about _why_ you got them shows far more 'talent' than someone who just repeated an experiment that is guaranteed to give good results.

      Sigh! Rant over. It is just crushing to see very little evidence of people designing their science lessons to impart the ability to think, like the guy who wrote Clouds in a Glass of Beer [amazon.com] did.

      • When in university physics lab, my partners and I did a sequence of rocketry experiments including thrust curves for the engines, design of a fuselage, wind tunnel testing, and ultimately launch and altitude triangulation.

        Our wind tunnel results conducted with a full motor showed decent stability. However, with a spent motor to simulate conditions in the unpowered flight segment, they showed considerable instability in the vessel. It was, however, extremely light (designed to maximize altitude for a given
    • by archeopterix ( 594938 ) on Wednesday May 14, 2003 @10:18AM (#5954374) Journal
      It hardly needs saying, but in a week I didn't make any amino acids I could detect.
      My high school experiment results were quite different - I had to throw the jar into a volcano after the evolved organisms created a civilization and started working on a technology to break the jar and take over the Earth. At least that's what I wrote in my paper. My mark was also quite different, and needless to say I wasn't very happy with it.
    • The chemical was ninhydrin. Reacts with primary amines to give a purple spot on TLC.

      Glass is a good blocker of UV. That's why one uses quartz cuvettes to determine the UV spectra of solutions from ca. 400 down to ca. 200 nm. I suspect this is where the good high-energy UVs that might have given you some chemical reactions are.

  • Article Text (Score:5, Informative)

    by Anonymous Coward on Wednesday May 14, 2003 @09:53AM (#5954167)
    Primordial Recipe: Spark and Stir
    Date Wednesday, May 14 @ 00:48:06
    Topic Extrasolar Life

    No single experiment, according to Carl Sagan, has done more to convince scientists that life is 'likely abundant in the cosmos' than the work fifty years ago by then graduate student, Stanley Miller. This week celebrates his milestone publication, and Astrobiology Magazine interviewed him about his work and reflections today.
    Primordial Recipe: Spark and Stir
    by Astrobiology Magazine staffwriter

    Fifty years ago on May 15, 1953, a University of Chicago graduate student, Stanley Miller, published a landmark two-page paper in Science magazine. He considered if amino acids could be made from what was known about the early Earth's atmosphere. Could the building blocks of life be cooked up?

    "... some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity etc...", Charles Darwin, on the origins of life in tidal pools
    Credit:Smithsonian

    Miller began his paper:

    "The idea that the organic compounds that serve as the basis of life were formed when the earth had an atmosphere of methane, ammonia, water and hydrogen instead of carbon dioxide, nitrogen, oxygen and water was suggested by Oparin and has been given emphasis by Urey and Bernal. In order to test this hypothesis..."

    When Miller first presented his experimental findings to a large seminar, it is reported that at one point, Enrico Fermi politely asked if it was known whether this kind of process could have actually taken place on the primitive Earth. Harold Urey, Stanley's research advisor, immediately replied, saying 'If God did not do it this way, then he missed a good bet'. The seminar ended amid the laughter and, as the attendees filed out, some congratulated Stanley on his results.

    Although Miller had submitted his paper in mid-December 1952, one reviewer did not believe the results and delayed its publication until May 15th. Later Carl Sagan would do many experiments varying the chemical percentages, but described the Miller-Urey experiments as "the single most significant step in convincing many scientists that life is likely to be abundant in the cosmos."
    Early Earth: Flash in a Flask
    Even today, only a few definitive things are known about what the Earth might have been like four billion years ago. It is thought that the early sun radiated only 70 percent of its modern power. No free oxygen could be found in Earth's atmosphere. The rocky wasteland lacked life. Absent were viruses, bacteria, plants and animals. Even the temperature itself is uncertain, since three schools of thought today maintain that the Earth could have been alternatively frozen, temperate or steamy.

    Charles Darwin imagined life springing from a temperate world, with small ponds or runoff channels. Compared to diluted chemistry in a vast ocean, repeated evaporation and refilling have possible advantages, to find just the right concentrations somewhere so that biochemistry could begin. Glaciers, volcanoes, geysers and cometary debris potentially resupplied this primordial pond with both energy and more complex organic compounds. That is a scenario requiring relatively temperate starting conditions, and more extreme possibilities are also in the mix.

    If the early Earth was a cauldron of volcanic activity, then seepage of acidic gases and heating might have circulated vital compounds to the surface. These vents may have been underwater, and precursors to biochemistry like acetic acid may have become reactive in combination with carbon monoxide. Alternatively, if the early Earth lacked any greenhouse of blanketing carbon dioxide, life could still have begun in a ball of ice. When combined with water, even a thin atmosphere of organics (formaldehyde, cyanide and ammonia) can create some building blocks of life (such as the amino acid, glycine). Thawing this 'snowball Earth' could then be triggered by a chance collision with large comets or meteors.

    Terrestrial options for ea
  • Miller had an unknown aide during this project. He spent a lot of time working with the fledgling life forms as they formed a society and culture. They became to see him as a God, and worship him.

    One fateful day, they managed to shrink the aide using a debigulator device, so he could lead their civilization. When he demanded they unshrink him, they were indeed astounded by the very notion of a re-bigulator device.

    True story.
  • by tundog ( 445786 ) on Wednesday May 14, 2003 @09:56AM (#5954195) Homepage
    I stopped eating primordial soup because the amino acids keep giving me heartburn.
    • I stopped eating primordial soup because the amino acids keep giving me heartburn.

      You should have tried synthesizing some of those a-nicer acids instead. (boom-boom)
  • another interview (Score:5, Informative)

    by AbdullahHaydar ( 147260 ) on Wednesday May 14, 2003 @09:58AM (#5954207) Homepage
    from October 1996: Exobiology interview [accessexcellence.org]

    On a related note: exobiology vs astrobiology? which do people prefer? (The definitions are in the links)
    • "Astrobiology" is the term that is usually used in such circles. We actually discussed this the first day of graduate Astrobiology a couple of years ago. The term "exobiology" seems to have fallen by the wayside for whatever reason. (Possibly because "astrobiology" gives an immediate sense of what the field is, while "exobiology" leaves many people wondering "outside of what?")
  • by Schezar ( 249629 ) on Wednesday May 14, 2003 @09:58AM (#5954211) Homepage Journal
    For two years, I bugged my Biology teachers to let my try the Miller experiment with the school's equipment. (Of course, I was the same one who wanted them to let me make a gauss rifle, a betatron, and potato gun...)

    I remember being fascinated when I first heard of the experiment. It seemed so 'important,' despite the fact that they brushed right over it and no one else in my classes understood or cared.

    Of course, now I'm in college, and I can try all of these things with my own equipment.
  • ...broke down as fast as they were made (in a carefully customised device, not in the wild), and were completely racemised at formation? Or that no evidence of a reducing atmosphere exists?

    Just like every other fairy tale: exciting, adventurous, believable, and wrong.
    • Just like every other fairy tale: exciting, adventurous, believable, and wrong.

      Yea, like that crazy thing about men landing on the moon.
    • Of course it didn't prove anything, but it was a first faltering step at least toward understanding how life might have originally began.

      Aren't we now seeing some evidence that certain precursors to single cell life are formed around thermal vents on the ocean floor?

      Carl Sagan aside, didn't Millers experiment rise above the level of fairy tale at the very least? Possible, but not probable, I agree, but it does have some significance in the search for an answer, at least to me as an armchair scientist.
      • by Anonymous Coward on Wednesday May 14, 2003 @10:25AM (#5954436)
        The significant thing is that Miller was able to produce amino acids in the first place. leonbrooks is using the classic fundamentalist creationist tactic of taking a scientific success and portraying it as a failure because the experiment did not meet 100% of the artificial requirements that he has generated for it.

        This is the same thought process that causes them to say "Evolution can't possibly be true because there is a missing link between species A and species C," and then when species B is discovered, they say "Aha! Now you have even bigger problems, because there is no link between A and B, and B and C!" :-)
    • If you're claim things like that, then lets have a reliable source please. A google for "stanley miller" racemized gives 5 results, all for Creationists' pages.

      broke down as fast as they were made

      What does this mean? Do you mean that they existed for zero time (impossible?), that their breakdown process lasted as long as their creation process (meaningless?), that as more amino acids were created an equal number broke down (not much of a criticism?)
      • broke down as fast as they were made

        What does this mean? Do you mean that they existed for zero time (impossible?), that their breakdown process lasted as long as their creation process (meaningless?), that as more amino acids were created an equal number broke down (not much of a criticism?)

        My guess is that the experiment reached an equilibrium concentration of amino acids, and the creationists think that this is somehow a problem :-)

      • Re:Evidence please! (Score:4, Informative)

        by Sgt York ( 591446 ) <jvolm@earthlin[ ]et ['k.n' in gap]> on Wednesday May 14, 2003 @01:58PM (#5956443)
        If the mix wasn't racemized, I would seriously think he had falsified the data. The amino acids were made chemically, not biologically. Any chiral compound made chemically will be racemic. (All but one of the amino acids are chiral)

        It should be no surprise at all that the mixture was racemic. The reason only Creation "scientist's" websites say anything about it is because they are the only ones that think it has any relevance.

        As for breakdown, they did break down quickly, that was in the original publications of the experiment.

        The "break down as quickly as they are made" is a half truth. At the gas-liquid interface, this is true. The amino acids did break down very rapidly. However, a fraction of the products became dissolved in the liquid soon after formation, and were preserved. This caused a gradual buildup of product.

    • ...broke down as fast as they were made (in a carefully customised device, not in the wild), and were completely racemised at formation? Or that no evidence of a reducing atmosphere exists?
      These days, his contribution is regarded as being the first of a series of studies showing that the fundamental building blocks of life are readily formed under a wide variety of conditions.
    • Obviously Wrong (Score:5, Informative)

      by ebuck ( 585470 ) on Wednesday May 14, 2003 @11:04AM (#5954813)
      Racemic mixtures are not decompsed anything. They are mixtures of "mirror-image" molecules. A completely racemized mixture is one with equal numbers of "left" and "right" members. Presence of both will not prevent you from using one or the other.

      Look at you set of hands, one is racemic "left" and the other is racemic "right". You have a completely racemized mixture of hands. This does not deny you use of your left hand.

      If amino acid procduction is industrial, usually you get (depending on the process) a mixture of the two racimic (D and L) formations that an amino acid can take. They are mirror images of each other.

      Why is this important, well on planet Earth, almost all amino acids involed in life are of type L. (Metorites and non-living processes contribute the majority, if not all, of the D racemes discovered today)

      Why only L-amino acids? Today we do not "know" with 100% certainty, but the theory is a living system, for whatever reason, started producing L-amino acids, which unbalanced the ratio. Other living systems (or perhaps the same one) which harvestd these L-amino acids survived and thrived in this L-amino acid rich environment while those that required D-amino acids may have never existed or may have died out due to competition.
    • ..broke down as fast as they were made (in a carefully customised device, not in the wild), and were completely racemised at formation? Or that no evidence of a reducing atmosphere exists?"

      I think you should take a look at the article. The "carefully customised" device is incredibly simple, consisting of 2 flasks, a hot plate, an electrical sparker, a water condesor, and some glass tubing. That's it. It could be further simplified to remove the heater, as all this does is to make more vapor available i
  • I've duplicated his results in my refridgerator and now have some primordial soup in there. It's chicken noodle primordial soup and tastes great with fresh baked bread.
  • by MongooseCN ( 139203 ) on Wednesday May 14, 2003 @10:04AM (#5954264) Homepage
    Would the experimentor claim intellectual property rights to the amino acids he found? "Sorry you can't use those drugs, I own the rights to all life on this planet."
  • It was my understanding that there is more than enough organic chemistry in comets to seed the early earth with the necessary components. Or at least, it would be a significant fraction, since the early earth would have had a lot of collisions from interplanetary debris. We find lots of interesting chemicals in asteroids and comets.

    I guess the question is to what extent did this seeding speed the development of life: would the chemistry have developed without a steady rain of complex molecules from the hea
    • So, what you are saying is just as when I leave a 1/2 cup of coffee left uncleaned before I go on vacation, some obscure mold develops, a comit might be the galactic equilivent of someone who just needs to do dishes more often, and life can be percieved as a slime mold film that develops as a direct result of no one being around to clean up the organic trash?
  • My 2 cents (Score:2, Interesting)

    by arvindn ( 542080 )
    I strongly feel that there are many planets harboring life in the galaxy. Consider this: what are the planets that we can directly observe to test for life? Clearly only those in the solar system. What have we found? It is thought to be a significant possibility that Mars had primitive life at some point in the past. Of course, the earth itself must be discounted because of the anthropic principle: if there weren't life on earth we wouldn't be around to ask the question. So out of a single observable planet
  • Is that they forget to add the red phosphorus and iodine to the mix.
  • You know, like this [slashdot.org]?

    BTW, I think 451F is hot enough to "un-do" the amino acids :-)
  • by Pall Agamemnides ( 673074 ) on Wednesday May 14, 2003 @10:26AM (#5954445)
    Come back, one year!
  • by DavidPesta ( 673248 ) on Wednesday May 14, 2003 @10:49AM (#5954660)
    The production of amino acids on the early earth is neccessary for spontaneous generation, but amino acids are extremely simple compared to proteins and cellular structures. One would expect amino acids whether the spontaneous generation of life happened or not.

    Saying that the existance of amino acids on an early earth proves spontaneous generation is almost like saying the existance of carbon and water on a planet proves the existance of life on that planet. Inconclusive!

    David Pesta
    B.S. Biochemistry

    • > Saying that the existance of amino acids on an early earth proves spontaneous generation is almost like saying the existance of carbon and water on a planet proves the existance of life on that planet.

      No ones says it "proves" anything, except that amino acids can be made from lifeless matter.

      But consider how differently we view the building blocks of life now than our ancestors viewed them 500 years ago, because of experiments like this.

  • been run for? I mean, has anyone set up a big tank o' goo, shocked it and shone uv light in it for several years, to see what develops? COuld life actually evolve(theoretically, i know statisticlly, it wont happen) in such a circumstance?
  • by Anonymous Coward on Wednesday May 14, 2003 @10:54AM (#5954709)

    Of course, Creationists don't take this theory seriously, because why would there be a glass flask on prehistoric Earth in the first place?

  • by Tsali ( 594389 ) on Wednesday May 14, 2003 @11:04AM (#5954810)
    All 21 chemicals can be found in a bucket of Kentucky Fried Chicken...
  • by paiute ( 550198 ) on Wednesday May 14, 2003 @11:13AM (#5954894)
    Replies to several different posts (sorry for the lack of attribution): /Ah, but does he mention that his amino acids... /broke down as fast as they were made (in a /carefully customised device, not in the wild), /and were completely racemised at formation? Or /that no evidence of a reducing atmosphere exists?

    Amino acids tend not to break down much. They are exceedingly stable once made. Those that happened to wander back into the electric current might have suffered, but the majority would have stayed safely in solution. The chemical reaction was proceeding in the gas phase; the products were sequestered in the water.

    The products are racemic amino acids. Several plausible hypotheses have been put as to how it happened that the L amino acids became predominate: circular dichroism in natural radiation, preferential decompostion of D 14C labeled amino acids, etc.

    We don't know all that much about the exact composition of the atmosphere at every time in the earth's history, but the fact that high-energy processes can give amino acids from simple precursors trumps all nit-picking. /Also Miller had to create a "trap" to collect the /amino acids being formed to protect them from /breaking down again. What would the comparable /"natural" trap be?

    The natural trap would be water. High energy events are always happening in the atmosphere (lightning, UV rays, cosmic rays). Lighting blasts convert nitrogen to nitrates. Roughly 10% of the nitrate in soil comes from nitrogen transformed by lightning, and the nitrates are trapped by water. The point to take home from the Miller experiment is that the small, high-energy intermediates formed by these processes can combine to form biologially complex building blocks. /As a student of Biological Anthropology, I have /had the oppertunity to take a history of /biological anthropology in which Miller was /mentioned. Interesting guy, but the theory is not /supported any more except by the few staunchest /researchers. In other words, this is pop science. /It survives in text books (like many other /evolutionary inaccuracies that nobody seems to be /willing to update). In truth, the experiment did /not conclude much. In short, the amino acid /theory in reality did not produce very much at /all

    This is just wrong. The conclusion drawn from the results of the experiment was revolutionary. It is of at least on the scale of Wohler's synthesis of urea, a biochemical, from "dead" cyanogen and ammonia.

    • by T5 ( 308759 ) on Wednesday May 14, 2003 @11:34AM (#5955071)
      In the last 50 years many, many scientific discoveries have been made that invalidate the Miller experiment. For instance, studies performed by NASA in the 1980's pertaining to the composition of ancient Earth's atmosphere debunk the Miller experiment's hypothesis that the atmosphere was composed largely of methane, ammonia, and hydrogen. They found that the atmospheric composition was dominated by nitrogen and carbon dioxide, with very little of Miller's hand-picked concoction present.

      The Miller experiment will go down in history as another irrational jump to conclusions based on a less-than-adequate scientific understanding to promote certain political needs in the scientific community in an attempt to prove macroevolution. I suspect that the only reason it's still promoted is political. It certainly isn't because it's good science. Decry the "nit-picking" all you wish, but the truth of the matter is that Miller's experiment, albeit revolutionary for the 1950's, is far from what modern science would ascribe as (1) reflective of the conditions of primeval earth and (2) extremely unlikely to occur even in the best of circumstances in the wild.
    • Interesting guy, but the theory is not supported any more except by the few staunchest researchers. In other words, this is pop science. It survives in text books (like many other evolutionary inaccuracies that nobody seems to be willing to update). In truth, the experiment did not conclude much.

      I'm not qualified to pass judgment on the merits of his argument (and you provided a nice defense of it) but my experience is that the quote is a perfect description of how Miller's work is perceived in the evoluti

  • ...could someone tell us if and how the remaining 8 essential amino acids can be formed?
  • by fzammett ( 255288 ) on Wednesday May 14, 2003 @12:08PM (#5955375) Homepage
    I remember it very clearly... It was 10th grade biology. My teacher mentioned the experiment and I remember very vividly that I was so taken aback by what he was saying. It seemed so immensely important and profound, and yet no one else in the class seemed terribly interested. I was simultaneously excited and sadened.

    Excited because I'd learned of something so seemingly important, and sadened because no one else seemed to see the importance of it.

    That was also the year I saw the first images of atoms, that one where they had written the letters IBM with Xenon atoms. That was another tremendously shocking experience.

    Is it just me or does the vast majority of the general population no longer see the importance of pure science? Are we so accustomed to amazing developments and incredible pieces of technology surrounding us all the time that things like these just don't impress us any more?

    Seeing atoms SHOULD amazes us. Learning of the building blocks of life being created from scratch in a jar SHOULD boggle our minds. Yet so many people shrug things like this off and don't see the fundamental nature of them.

    Ok, now I'm just sadened!
  • Miller is defunct (Score:5, Interesting)

    by searleb ( 168974 ) on Wednesday May 14, 2003 @12:24PM (#5955529) Homepage
    For more information on Miller and prebiotic Earth, here is a quotation from an Angew. Chem. review article by Kay Severin called Hot Stones or Cold Soup? New Investigations on the Endogenous Origin of Organic Compounds on Earth (Angew. Chem. Int. Ed 2000, 39, No. 20). It pretty much sums up the Miller reactions, why they're wrong, and what people think now:

    "The most famous experiment ... was carried out almost fifty years ago by Stanley L. Miller, at that time a PhD student in the group of Harold Urey in Chicago. Miller was able to show that electric discharges in an atmosphere of methane, ammonia, hydrogen, and water led to the formation of significant amounts of various amino acids. Experiments of this kind were repeated in numerous variants. If reducing gases were employed mixtures of organic compounds of low molecular weight could be detected in many cases. This has led to the popular idea that the primordial ocean resembled a nutritious soup.

    "But the possibility that earth once had a reducing atmosphere is questioned. A well known argument against it is the high photolability of methane and ammonia. Because a shielding layer of ozone was missing a high concentration of these gases is believed to be unlikely. Furthermore, several other results point to a neutral atmosphere of CO2 and N2. Given the fact that the atmosphere was based on an unproductive mixture of CO2 and N2 the nutritional value of the primordial ocean drops significantly.

    "An alternative scenario has been propagated for several years by [Gunter] Wachterhauser. Instead of a primordial soup he favors hot minerals as the place where organic molecules were initially built as life subsequently emerged. Especially sulfur-containing minerals like pyrite are proposed to have acted as an energy source and catalyst both under the extreme conditions found in hydrothermal or volcanic vents."

    Basically, primordial soup syntheses (like Miller's reactions) are out and hot rock syntheses are in. These hot rock procedures have much much much lower yields, but people are slowly figuring out how to build amino acids through them. For instance, people, headed by Wachterhauser, have figured out how to carbon fixate (condense) carbon monoxide and carbon dioxide into organic building blocks for amino acids. For instance, in early 2000, Chen and Bahnemann were able to convert CO2 and water to small organics (acetaldehyde, ethanol, acetic acid) at high pressures and temperatures. Similarly, people have figured out how to take amino acids and convert them into peptides under high temperature and pressure situations.

    However, to date no one has been able to actually make an amino acid through these techniques. As a result, the proof that amino acids were delivered by comets or meteorites (true fact, this is not an x-file) and now space dust, becomes much more appealing. Once the building blocks arrived on Earth, these hot rock syntheses could have taken over.
    • Not Defunct (Score:3, Insightful)

      by RatBastard ( 949 )
      He's not defunct. His point was that the building blocks of life - complex organic molecules - can be formed from inorganic molecules. And he was right, and still is right.

      The actual mechanism might not be what we thought it was then, but that is irrelevant.

      Does the fact that gravity may function by means of gravatons invalidate the work of Isaac Newton?

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