The origin of life

I have been having a lot of fun debating the origin of life over at Not PC. Nothing like a bit of good scientific debate to provide a break from my normal science!

Most people assume that life originated in some “primordial soup” way back in the distant past. But this doesn’t work scientifically.

Say we assume that by some fantastic miracle, we got a puddle on the early earth that contained all the building blocks of life – DNA, RNA, protein, lipids etc. We can replicate this by taking a plant and putting it through a blender.

If we leave our blended plant for a while, will we get life forming in this soup? No, the chemicals in it will all break down over time following the laws of chemistry and thermodynamics.

If we put this soup in the sun for a while, giving it the input of energy, will we get life? No, the chemicals will just break down faster. The added energy simply speeds up the processes that must happen. We will get cooked soup. If we are lucky it may be tasty.

On the other hand, if we put the plant in the sun – exactly the same molecules, just organised into a complex structure – it will use the same energy through photosynthesis to grow.

So with a pre-organised system such as the plant, the energy input from the sun can be harnessed to create further order. However the disorganised soup will only become less ordered. There is no known scientific way to get over the hurdle from disorganised soup to organised living tissue, even if you did get a soup of all the right chemicals – which is in itself a chemical impossibility.

But when you present this to an atheist, they generally say something like this:

I’m not sure you wouldn’t get life if you left your blender long enough. Obviously, over the kind of time scales that humans are comfortable with, it’s unlikely that the plant will grow back out of its constituent molecules. However, we don’t know what might happen over hundreds of millions of years, with the addition of random other dust, lightning strikes, etc.

Ultimately, the atheist just ends up having faith. Despite all we know about chemistry and thermodynamics, which clearly states that the molecules in that soup would break down over time (they would actually react with each other and break each other down by the way), they are willing to disregard science and believe that somehow, something happened that science says is completely impossible. Just like in Frankenstein, the lightning hits and bang – the soup comes to life!

That is not rational, scientific logic. That is faith.

Science clearly shows life cannot come from non-life. Louis Pasteur showed this over a century ago, and the more we understand about biochemistry the more his early logic is confirmed. You can therefore conclude scientifically that life must come from life, and therefore the life we have today must have originated from another life.

This is rational. This is logical. This is consistent with the science.

The Christian will then believe through faith that original life was God. But acceptance of God or Christianity is not part of the argument at all, you don’t have to be religious to see that life only comes from life. You may become religious after you realise it though! 🙂

The atheist on the other hand must have faith that our current science is COMPLETELY WRONG! They are not following the science, but rejecting it in favour of some fairytale they hope will be shown in future to be true. All so they can believe in their presupposition that there is no God.

That is a leap of faith I am unwilling to take.

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25 Responses to “The origin of life”

  1. Dan Says:

    A couple comment tidbits:

    – your experiment: strictly speaking, it’s the heat alone that speeds up breakdown of the soup. As Miller and Urey showed (and others since), some very interesting organic chemicals can and do sometimes form under not-so-complex conditions.

    – As anyone working in a lab with organic chemicals will tell you, cleaning them up is a pain in the butt – because they don’t break down quite so easily. Heck, you’d know this even in the kitchen, if you cook something very fatty or greasy and leave it set for a few days (so it dries out), and then try to clean it.

    – Pasteur also argued that you’d never recreate cellular processes in vitro (outside cells and inside test tubes), but the molecular biologists of the 20th century proved that wrong.

  2. Mr Dennis Says:

    You can create some organic chemicals – amino acids are easy to create for example. But getting those to form a protein is an entirely different matter – and getting that protein to actually be a useful protein and not just a random string of amino acids is a whole extra level of complexity – and if you can, there’s just one protein. That won’t help you get much life. It will just break down again.

    Yes some organic molecules are fairly resilient. But you don’t just need them to exist, you need them to exist in the right form. For example, you can have a protein in its correct configuration. Add a bit of heat and it will denature – it changes shape. It is still a protein, and might stick to your frying pan, but will no longer do what it is supposed to. For want of a better word, it is dead.

    We can do more and more in our fancy laboratories. But ultimately, even if someone did manage to create life in the lab, what would that prove? Only that with millions of dollars of investment and the cumulative expertise of centuries of science, intelligent humans can create life. In other words, life creates life! It wouldn’t show that life could originate by chance, in fact it would show how difficult it is for life to occur!

  3. Dan Says:

    What’s to say that some sort of chemical “evolution” didn’t occur, based around a naturally-occurring cyclic reaction? For instance, some researchers point to the relative ease with which a reverse citric acid cycle could have occurred, generating an abundance of diverse building blocks and operating under completely accepted laws of chemistry derived from thermodynamics and kinetics. If you have such a situation, with a diverse array of chemical products, some of which being both high-energy and slow to breakdown (many energy-storing molecules fit this description in modern biochemistry), then the result would logically be an extremely high number of possible chemical outcomes, including even some accumulation of molecular complexity.

    Or that’s how it seems to many molecular biologists and biochemists, anyway.

  4. Dan Says:

    For more reading on the Reverse Citric Acid Cycle, or Reverse Krebs Cycle, there was a very helpful paper in JACS published in 2006:
    Driving Parts of Krebs Cycle in Reverse through Mineral Photochemistry

  5. Mr Dennis Says:

    Interesting theory, I don’t have the time to look into it in detail this morning but I will do later. However what this addresses is how you would get some of the molecules for your organic-molecule-rich soup in the first place.

    Note that in my illustration I already presume that “by some fantastic miracle, we got a puddle on the early earth that contained all the building blocks of life”, and illustrate this using a blended plant – a far better mixture of organic molecules than any chemical process could produce.

    And even with this ideal soup in place, you don’t get life. There are many, many stages to getting life from non-life, just making a few organic molecules in the lab really doesn’t prove much.

  6. Kiwi Polemicist Says:

    Yes, it would take a great miracle to get that puddle ex nihilo.

    The bizarre thing is that evolutionists accuse creationists of applying faith and ignoring science, yet evolution is neither demonstrateable nor repeatable.

    I quite agree that evolution is a faith, and the sad thing is that that faith is taught in schools:

    http://christianclassicalliberalist.wordpress.com/2008/12/29/a-biblical-perspective-on-home-schooling-and-state-schooling/

  7. Dan Says:

    Mr. Dennis,
    By what metric do you suggest that a blended plant is a better mixture of organic molecules to recreate abiogenesis? That is to say, why is that better than starting with a basal chemical feedback loop that I’ve suggested to you? Clearly the first proto-cells weren’t as complex as a plant cell…

  8. Mr Dennis Says:

    Because a blended plant, or any other organism for that matter, contains everything you would need for life – DNA, RNA, protein, lipids – and not only contains the basic chemical forms of these, but the actual proteins needed to do various cellular functions, DNA containing code for basic cellular functions etc.

    By contrast a basal chemical feedback loop would produce raw organic compounds, but not necessarily all those required for life.

    There is a basic level of complexity that must be surmounted before something becomes self-replicating. You need at least RNA, several specific proteins, a way of harnessing energy (proteins to manage ATP or some “simpler” equivalent), lipids for a cell wall (to ensure your chemicals actually stay together and can function) etc. Even a virus, which you may call a simple form of life, is not self-replicating, it needs a host – you must get more complex than that before you get life.

    All these components are provided by a blended organism. Few would be provided by chemical processes, and not in as useful forms.

  9. Dan Says:

    If you can’t so simple things like amplify DNA in “blended” extracts, for instance, why would you expect to reconstitute life from those blended extracts. It just doesn’t follow. However, by reconstituting the system in vitro with the minimal number of components necessary for for the reaction to proceed, it works.

    Hence, the blended organism is too complex to recapitulate simple, archaic reactions – for a simple reaction, you need equally simple ingredients, the kind of which you would have to work with in a prebiotic world.

  10. David W Says:

    I really doubt there’s much point in commenting here but, nevertheless:

    Mr Dennis, which do you think is the more appropriate scientific approach. Claiming that an event that everyone agrees happened (life did start somewhere didn’t it?) was so improbable that it must have required supernatural intervention or building hypotheses for how it might have happened (RNA word, chemical selection, hypercycles…) and testing them (and, for instance, finding out that you are wrong about self replication, RNA can do it by itself)?

    You’re welcome to make the origin of life a gap in which to fit god but what happens when the gap closes? A bunch of american protestants staked their religion on the idea that the earth is 6 000 years old – now they’re the laughing stock of the rational world. Wouldn’t want to see you making a similar mistake.

  11. Mr Dennis Says:

    I believe the best scientific approach is not starting with any preconception at all, and following the science where it leads.

    At present science states that life cannot arise from non-life. No-one has ever observed life coming from non-life, and although there are some hypotheses around how various compounds necessary for life could arise naturally, no-one has come up with a plausible explanation of how life could actually come from non-life – let alone replicated it in the lab. In fact, the more we learn about biochemistry, the more complex the whole issue becomes.

    Therefore when I say life coming from non-life by chance is impossible, I am just stating the science.

    We must then have faith in how it did happen. You may believe it came about by chance and have faith that one day science will figure out how. I may have faith that God created life. It is up to each of us to judge which faith is more rational. But both perspectives involve faith.

    “You’re welcome to make the origin of life a gap in which to fit god but what happens when the gap closes? A bunch of american protestants staked their religion on the idea that the earth is 6 000 years old – now they’re the laughing stock of the rational world.”
    Would you mind pointing me to the particular research that you are referring to here as “the gap closing”?

  12. David W Says:

    Mr Dennis,

    I don’t have ‘faith’ that science will one day provide a a definitive answer to the origin of life. I just don’t share your belief that it would have been impossible for life to have started from, say, interacting chemical cycles or the generation of an RNA like replicator. It’s a huge question, and we might never find the ‘one true answer’ but I’m not a believer so I’m quite happy with puzzles 😉

    I wasn’t referring to any closing of the gap, just that I’ve always thought the “God of the Gaps” was a pretty terrible idea theologically (you might not want theological advice from an atheist…) because you run the risk of looking stupid when the gaps get filled, as they often do. cf Paley etc

  13. Dan Says:

    I believe the best scientific approach is not starting with any preconception at all, and following the science where it leads.

    Unfortunately Mr. Dennis, even science must have a starting point for ensuing research and discussion. We’re just starting from differing “null hypotheses”, yours being that of divine intervention, ours being that of natural process.

    But that observation isn’t why I came back; I’d like to point out another facet of the “blended organism” scenario…

    Modern organisms are based on oxidizing metabolism (with the exception of some Archean bacteria), and the atmosphere prior to somewhere between 2.4 and 2.7 bya was a reducing, oxygen-poor atmosphere. So not only would your hypothetical blended organism be overly complex for recapitulating abiogenesis, it would be based on the wrong chemistry.

  14. Mr Dennis Says:

    “Modern organisms are based on oxidizing metabolism (with the exception of some Archean bacteria), and the atmosphere prior to somewhere between 2.4 and 2.7 bya was a reducing, oxygen-poor atmosphere.”
    Actually, you may not realise but the idea that the early atmosphere was reducing originates from the assumption that a reducing atmosphere would be necessary for the synthesis of organic molecules. The geological evidence for a reducing atmosphere is questionable (see reviews here and here).

    Therefore to say that a reducing atmosphere proves anything about the origin of life is circular reasoning – the reducing atmosphere is not a fact, but a hypothesis designed to give the best conditions for the spontaneous generation. The earth may well have had an oxidising atmosphere for its entire history. Just a side issue from my point of view, but I thought I had better point out the shakiness of your reasoning.

    My null hypothesis is actually that life cannot come from non-life through natural means – I am not bringing the supernatural into the science at all.

    This null hypothesis is not disproved anywhere – no-one has observed life coming from non-life. Therefore the null hypothesis is proved until evidence is found to dispute it.

    I then assume, from faith, that God created the first life – that is no longer in the realm of science. You assume, from faith, that life can spontaneously generate naturally, although science has found no evidence of this despite centuries of searching. That too is no longer in the realm of science.

  15. Dan Says:

    Well, I admit I’m not sure where the idea originated for a reducing atmosphere, but regardless, evidence does exist independent of biotic reasoning (Kasting, 1993):

    The first systematic attempt to [address O2 levels by the geologic record alone] was made by Cloud (Ref. 71). He observed that redbeds (oxidized subaerial deposits) were absent before about 2bya and that deposits of detrital pyrite and uraninite were mostly formed before this time. These minerals are usually oxidized during weathering under the high partial pressure of O2 of today’s atmosphere. Furthermore, banded iron formations (BIFs) were formed up until ~1.85bya (Ref. 72), but not after (Refs. 73, 74). Deposition of BIFs is thought to require an anoxic deep ocean so that iron can be transported long distances in its soluble ferrous form (Ref. 75).

    Most recent analyses of the rise of O2 levels are in general agreement with the model proposed by Cloud. Holland (Ref. 76) placed the time of major increase in levels of O2 at between 2.2 and 1.9bya on the basis of a variety of types of geologic evidence, incuding the analysis of paleosols (ancient soils).

    … and so on.

    Also, what something could not be is not a null hypothesis, it’s not any kind of hypothesis (you can’t test a hypothesis that would prove a negative). Therefore the affirmation must be what is hypothesized, which, in your case, is the intervention of some deity or another.

  16. Dan Says:

    Hmm… thinking about it some more, I probably should have left your null hypothesis response alone. Nevertheless, we’re still left with:

    – independent evidence for a non-oxidizing atmosphere prior to sometime 2-2.7bya (various methods of estimating the chronology differ, but they all agree that there was a time when the atmosphere was non-oxidizing)

    – the blended organism refutation of abiogenesis doesn’t work because it is (a) based on oxidizing chemistry incapable of recapitulating a reducing chemistry; and (b) it represents a bad methodology for reconstructing chemical reactions in cell-free environments.

  17. Mr Dennis Says:

    Dan, did you read the links I put in earlier regarding the geological evidence for a reducing atmosphere? If you have a look at those you will see the evidence is certainly questionable. The geological record appears inconclusive. So I feel it is more reasonable to not make any assumptions about the early atmosphere.

    Certainly the analogy of a blended organism can be picked away at – it is only an analogy after all. But can you by natural processes explain the origin of:
    – DNA or RNA containing coded information for self-replication
    – Proteins to carry out this replication
    – Proteins to manage the energy for this replication
    – Lipids for a cell wall to keep the reactions together
    – All in the same spot and in an arrangement where they may begin to form life?

    In reality the simplest form of life possible would be more complex than this. But that is a good starting point. Note that you need to explain not only the production of the basic components (amino acids etc) but their arrangement into complex structures (coded DNA and/or RNA, specific proteins etc).

  18. David W Says:

    Mr Dennis,

    At present science states that life cannot arise from non-life

    No, you do. And then you present a laundry list of things that modern life has as if anyone has claimed life as we know it arose it one fell swoop. What Pasteur and repeated observation has ruled out is the idea continuing spontaneous generation of complex, modern, life. Not the generation of simple life forms.

    For that you might need the spontaneous creation of lots of biomolecules (easy) the polymerization of those molecules (i don’t think this has been observed, but it’s certainly not, as you claim, impossible for anydrous reactions to achieve this) the generation of self replicating polymers (RNA can do that and preform reactions all by itself!) and then RNA world, RNA-protein world, DNA-protein world (that actually has lots more functional RNA than we’d realised) and you.

    You might think that steps along that path (or the many others that have been proposed) are unlikely but it’s not accurate to present them with imprimatur of “scientific” impossibility. You are welcome to your view, just don’t claim it is the only rational conclusion from the evidence.

  19. Mr Dennis Says:

    “You are welcome to your view, just don’t claim it is the only rational conclusion from the evidence.”
    And you are welcome to yours. The entire point of this post is not to prove my view to anyone, but rather to show that both theistic and atheistic beliefs about the origin of life involve faith.

    It is entirely up to you whether you feel it is more reasonable to believe in the existence of some ultra-simple lifeform which no-one has discovered yet, or believe in God. As I said, it comes back to faith.

  20. David W Says:

    I don’t faith in “some ultra-simple lifeform which no-one has discovered yet”. I don’t know how life began, I’m just happy to live with a certain degree of uncertainty in my life (outside of Richard Dawkins and a few people that read Ayn Rand at an impressionable age most atheists don’t claim absolute certainty. Just no reason to beleive.)

  21. Mr Dennis Says:

    So you mean you don’t know how it happened but you have faith that it happened without God?

  22. Dan Says:

    No, I didn’t read the links you provided earlier. Sorry, as a biologist, I thought you were joking when you linked to ICR. Can you try to link to something that’s not on a propaganda site next time?

    To your requests to explanations, yes, or at least I can explain likely scenarios to each based on what knowledge we have available. Which is where your reply to David comes in:

    So you mean you don’t know how it happened but you have faith that it happened without God?

    From your earlier comments, I know that you concede that we can make fundamental inferences based on what information we have available. So why are you pulling out this red herring that incomplete knowledge = no knowledge. You’re better than that.

    And your last bit of reply to me:

    In reality the simplest form of life possible would be more complex than this.

    Right, which is why I was talking about a plausible intermediate stage, the Reverse Citric Acid Cycle, which is neither alive nor complex, but still possesses a necessary first component to life: metabolism.

  23. david w Says:

    So you mean you don’t know how it happened but you have faith that it happened without God?

    No, given the abundant evidence that order can increase in chemical and proto-biological systems by selection and other means I think, on balance of probability, that life arose on earth by naturalistic means. I don’t have faith in that because I’m not a beleiver. Atheism isn’t about out and out denial of the possibility of a God, it’s just not thinking there’s much reason to believe in one ( I also don’t think “GodDitIt” is a more parsimonious explanation than dissapative structures, hypercycles and auto-catalysis.)

  24. Tom Says:

    The primordal soup theory is quite an old and discredited theory for the origin of life. Your critisism is not entirely inaccurate, but there are several theories that are much more feasable, including many that involve “chemical evolution”. The complexity of these theories will probably mean that none are proven, but that doesnt mean that it didn’t happen. If life came from no life, it is bound to be complex, but the inevitable complexity does not disprove it.

    One theory to give you an idea of the different theory, is that life started in deep sea hydrothermal iron sulfide vents. There was a redox gradient moving through the vents allowing carbon fixation, the theory is that the carbon molecules interacted with the iron sulfides, and these mediated reactions. The compartmentalisation would have allowed a certain type of chemical evolution, the compartments that made chemicals that aided catalysis, would fix more carbon, being almost self replicating.

    There are a number of enzymes with FeS and Fe,NiS centres that resemble structures likely in these Fe,Ni,S vents. And a number of analogous reactions to those that the enzymes catalyse have been shown to occur in the presence of Fe,NiS in the lab.

    I’m not arguing that there is no god, but you dont have to look at a piece of science that is far too complex to prove or disprove. However there is enough evidence to show that it isn’t an entirely illogical suggestion that life started from no life.

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