Chemical evolution:

Discussion in 'Biology & Genetics' started by paddoboy, Aug 7, 2020.

  1. Q-reeus Valued Senior Member

    Messages:
    4,167
    Simple bubbles formed from prebiotic polymer goo have no feasible way of naturally transforming into sophisticated functioning cell membranes. Unless the huge number of steps in between occur in the lifetime of a single bubble polymer 'primitive cell', that cell dies. This process of a self-replicator complex being encapsulated by a simple bubble, hugely unlikely in itself, therefore at best repeats on rare occasions with no incremental gain being able to be passed on. No integral relationship as exists in modern cells, could ever develop. An obvious show-stopper once one pauses to think it through logically. Commitment to the Darwinian paradigm doesn't allow that.
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Write4U Valued Senior Member

    Messages:
    16,170
    Permit me to offer a simple evolutionary chronology of cell formation from simple "bubbles" formed by surfactants.

    Please Register or Log in to view the hidden image!


    Cross-section view of the structures that can be formed by phospholipids in aqueous solutions (unlike this illustration, micelles are usually formed by single-chain lipids, since it is difficult to fit two chains into this shape)


    Please Register or Log in to view the hidden image!


    Schema of a liposome showing phospholipid bilayer surrounding an aqueous interior and excluding an aqueous exterior environment

    And evolving over a few billion years of 2 trillion, quadrillion, quadrillion, quadrillion chemical trials and errors into a compound cell with other dynamical bio-chemicals inside it, capable of self-copying and strategies for energy conversion to maintain homeostasis.

    Please Register or Log in to view the hidden image!


    Liposomes are composite structures made of phospholipids and may contain small amounts of other molecules. Though liposomes can vary in size from low micrometer range to tens of micrometers, unilamellar liposomes, as pictured here, are typically in the lower size range with various targeting ligands attached to their surface allowing for their surface-attachment and accumulation in pathological areas for treatment of disease.[1]

    Of course the above illustration is of an artificial structure, but if we can make it in a lab, nature can and most likely has already produced it .

    Please do not take this as a real world scenario, but rather as an illustration of possible evolutionary progressions of self-organization from simple to complex structures.

    In a dynamic environment rich with a near unlimited variety of available bio-molecules, water, time, and temperatures, it is not only possible, but under certain circumstances is becomes "necessary" for certain self-organizations to begin forming a variety of host cells capable of growing or dividing, repelling or attracting, or assembling into complex compound structures capable of performing work which is impossible for the individual constituents.

    Don't forget that "to be or not to be" is not an "either-or" choice, but a matter of a range of probabilities.
    Hazen explains these things so clearly and has the required knowledge to speak authoritatively about these things.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Q-reeus Valued Senior Member

    Messages:
    4,167
    A carefully cataloged reality check:
    http://www.godandscience.org/evolution/origin_membranes.html
    (don't neglect to read the inset titled 'Primitive Membranes' on right side of article. More or less repeats my last post, with some extras thrown in. )
    So many high hurdles to be jumped. A crucial extra one not covered there is origin of homochirality. But below the article proper a relevant link is given:
    http://www.godandscience.org/evolution/origin_homochirality.html
    True Believers in the 'inexhaustible powers' of Darwinian evolution won't allow themselves to be fazed.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Write4U Valued Senior Member

    Messages:
    16,170
    That's just wrong. It is the inexhaustible powers of the Universe and Natural selection that make Darwinian evolution true. These are proven facts.
    Primitive Membranes
    http://www.godandscience.org/evolution/origin_membranes.html

    "Would die soon" is a meaningless projection. All speculations are only of the kind that "this could not have happened by itself" and must have had a "helping hand". There is no physical mathematical proof of "impossibility" anywhere.
    There is proof that on earth, during 3.5 billion years of 2 trillion, quadrillion, quadrillion, quadrillion bio-chemical evolutionary transmutations and physical experiments these things did in fact happen.
    (These objection are like the objections voiced by the Pennsylvania Senator and some Legislators to the results of the elections, in spite of the assurances by the state's auditors that the vote was legitimate and true.)
    They are just stubborn speculations without proof, whereas evolution via natural selection is proven fact. DNA is not an irreducibly complexity from Intelligent design, because DNA is not perfect. It has many non-fatal flaws, but it is constantly evolving and it's the chemical coding for the formation of all cells in your body. Are you telling me DNA is written by God?

    All the talk of "cannot" does not prove anything. RNA and DNA are fact and these processes are going on as we speak. If you think transmutation and evolution have stopped, you are mistaken. The process is ongoing in our bodies, on earth, and everywhere throughout the universe.

    We are currently exploring evidence of these type processes in our local solar system with the rovers and someday we will be able to explore more primitive planets elsewhere with probes.
     
    Last edited: Jan 7, 2021
  8. iceaura Valued Senior Member

    Messages:
    30,848
    ?
    There's always Darwinian evolution - odd you would overlook the obvious, in a thread with the word "evolution" in the title.
    Which argues against whatever theory you applied there.

    In Darwinian evolutionary theory there is no such problem - no "cell" (primitive or otherwise) necessarily exists at this stage of a Darwinian evolutionary sequence, there is no such thing as a "lifetime" in any biological sense, nothing necessarily "dies", etc.
    The origin of homochirality is among the lower hurdles - homochiral substrates of hundreds of different kinds are common even now, self-assembling all over the place even on a planet covered with feeding and environment altering living beings.
    Now you know why Darwinian theory was and is regarded as such a profound advance, and the most likely theory for explaining abiogenesis.
     
    Last edited: Jan 7, 2021
  9. James R Just this guy, you know? Staff Member

    Messages:
    35,782
    Who knows? We haven't seen any to allow us to study them, yet.

    Until you have the "how", you don't have a scientific theory of abiogenesis. You just have a bunch of poorly-justified assumptions.

    Don't tell lies. If you knew how life started, you would be able to point to a process of the kind that I previously walked you through. The fact that you can't point to any such process means that you don't know.

    You speak as if intoning the mantra word "abiogenesis" is somehow equivalent to an explanation. It isn't.

    That's your own guess, is it?

    Is any of those things life?

    Which is it: a living thing or a non-living thing?

    So you've identified one rung on a ladder. Where are all the other rungs? The ones you'll need before you can claim to have a theory of abiogenesis?
     
    Last edited: Jan 7, 2021
  10. Write4U Valued Senior Member

    Messages:
    16,170
    You have completely lost me here.
    Life has always existed? There was no beginning of life, ever? Everything has always existed? There was no beginning to everything, ever? There is only eternal life and everything?

    You can't be serious. There has to be a beginning to everything. There was a beginning to this Universe. Hence there was a beginning to everything within this Universe, including life, even if there is a greater multiverse with life elsewhere. It would be outside this spacetime geometry.

    Are you prepared to argue that there was no BB and a no beginning to this universe?

    AFAIK, that is no mere speculation. I don't need to prove this. It's Mainstream Science, a term we are so fond of citing.
    And if I understand logic, each input value of a function corresponds to exactly one output value.

    If I am wrong please correct me. I like to know plain truth.
     
  11. James R Just this guy, you know? Staff Member

    Messages:
    35,782
    In our universe? Apparently not. Elsewhere? There's no way to know.

    The word "abiogenesis" implies a beginning of life.

    Depends what you include in "everything". Who knows?

    Nobody knows.

    Tell me why there has to be a beginning to everything. How do you know this?

    Probably you're thinking of the big bang, but we don't have a description of the big bang back to time zero, so who knows what happened in the early times? You can't, for example, honestly claim to know that the big bang was uncaused.

    And so?

    No. I don't need to do that in order to establish that there is no scientific theory of abiogenesis, which is my main point of contention with you in this thread. For some reason, you've decided to adopt paddoboy's indefensible stance that a scientific theory of abiogenesis currently exists, even though you're unable to reference any such theory, or provide even a summary of its content.
     
  12. Hercules Rockefeller Beatings will continue until morale improves. Moderator

    Messages:
    2,770
    Perhaps there’s a lack of understanding of each other’s standpoint. May I ask some questions to clarify (as I don’t want to read through this long thread)?

    James, are you saying there’s no “theory of abiogenesis” in the same way there are other theories in the biological sciences that describe evolution, cells, viruses, DNA, infection, etc etc? There is no precisely delineated pathway through which matter organised itself into self-replicating evolving entities. Rather, there are a variety of hypotheses that cover a range of potential mechanisms by which this might have occurred. You’re not disagreeing that abiogenesis occurred but, rather, that we aren’t entirely sure which of the proposed mechanism(s) drove abiogenesis and no framework for making undiscovered predictions. Thus, we’re dealing with hypotheses, not a theory.

    Does the above paragraph sum up your position? If yes, then I’m firmly on JR’s side.
     
  13. James R Just this guy, you know? Staff Member

    Messages:
    35,782
    Hercules Rockefeller,

    Very good to see you! I hope you're well, have had a good Christmas break, etc. etc.

    I'm fairly confident that, several times in the preceding 750 posts of this thread, I have clearly and precisely explained my position. Initially, I was in dispute with paddoboy. Then, after that discussion had mostly run its course, Write4U decided to jump in to try to defend paddoboy's position, as well, starting back at square one without giving any sign of having read what went before. So, I then explained carefully, again, for Write4U's benefit, what my objection was. He ignored my explanation. Recently I have asked him several times if he is able to state my position in a sentence or two, just so I know he actually understands it. So far, he has been unable to do that without making various errors, which I have tried to help him through.

    Of course.

    Precisely. It's a simple enough point, but one that has continues to elude both paddoboy and Write4U for some reason. I think the main reason is that neither of them is actually willing to listen to any challenges to their assumptions. Objections to their views just fly over their heads, so that in a post or two (often their very next post), they repeat the very arguments that were just debunked.

    Thank you, kind sir. It's nice to see that somebody around here can be reasonable.
     
  14. QuarkHead Remedial Math Student Valued Senior Member

    Messages:
    1,717
    I.m sorry, JamesR, but I think you are being disingenuous.

    Look, neither paddoboy nor Write4U have a formal science or mathematics education - I am sure they will freely admit it. As such, they have not been trained to use terms with the same precision that a scientist or a mathematician would. This is not a crime.

    So cut them some slack. It seems obvious to me that when they use terms like "theory of biogenesis" they merely mean to support the idea that there is, or must be, or will be, some theory using established, or as yet unknown, process in chemistry, physics or evolutionary biology that explains the origin of life.

    Bear in mind they were responding to some nutcase who rejected "mainstream origin of life theories and Darwinian evolution".

    It seems to me they have simply been arguing the case for a probable scientific explanation as opposed to a supernatural one.

    Either one will correct me if I have misinterpreted them
     
  15. Q-reeus Valued Senior Member

    Messages:
    4,167
    You are of course obliquely referring to me. One 'nutcase' to another then:
    http://www.sciforums.com/threads/bi...-of-thermodynamics.163538/page-2#post-3648245
    An anti-relativity nutcase that rejected a clear implication of gravitational redshift. How bad is that!
    But returning to the topic here: Since anyone finding fault with Darwinian theory is evidently a 'nutcase' in your reckoning, I'll assume you can easily refute my 'nutcase' post #741. By refute I mean provide a coherent, empty-rhetoric free, detailed exposition. That would be a first here. I have zero expectation you can deliver. That you prop up noisy (and in one case an utterly disrespectful) fools is repugnant to me. As is the use of pejorative 'nutcase'.
     
    Last edited: Jan 9, 2021
  16. James R Just this guy, you know? Staff Member

    Messages:
    35,782
    No. It could well be that paddoboy was being disingenuous throughout the disussion, though. It could also be that, instead of failing to understand the point, Write4U is simply being disingenuous.

    I agree with you. That is why I patiently and carefully walked both of those posters through the difference between how scientists use the word "theory", compared to how it is often used in ordinary conversation (i.e. to mean something like a hypothesis).

    I also gave specific, helpful examples of what a "theory of abiogenesis" would look like, from a scientific point of view, if one were to be found eventually.

    It is possible, of course, that both paddoboy and Write4U are too thick to understand careful and precise explanations, such as the ones I gave them. It is also possible that they understood perfectly well but for other reasons were unwilling to concede the point.

    I understand that's the impression you might get, if you haven't carefully read through the entire conversation. However, both paddoboy and Write4U have continued to insist there is a "theory of abiogenesis", even after I spent many posts patiently trying to educate them about the point I was making, and about exactly where I agreed with them and where I disagreed.

    I might also note that a number of other posters in this thread understood my point immediately, and agreed with me, so although it is conceivable that my explanations were not very good, that seems unlikely.

    Following all the discussion, my own impression is that paddoboy understood the point I was making to him, but was then unable to bring himself to admit that I was right and he was wrong. That is evidenced by the change in the language he used as our discussion progressed. By the time he went off in a huff, he was saying he didn't care about the theory/hypothesis/assumption distinction, which is just another ego-protection mechanism deployed by him so that he could feel justified about being dishonest.

    My impression is that Write4U still doesn't understand the difference between what scientists call a theory and what he calls a theory. I have asked him several times to summarise my position in his own words. He has been unwilling or unable to do that, so far. Instead, he is insisting I have made a "category error", whatever that is supposed to mean. (I think it's a smokescreen.)

    I have been clear that I agree with them entirely on that point. Nevertheless, they have continued to argue against my position.
     
    Last edited: Jan 9, 2021
  17. James R Just this guy, you know? Staff Member

    Messages:
    35,782
    Says who?
     
  18. Q-reeus Valued Senior Member

    Messages:
    4,167
    Says me - as explained in the rest of that post! But not just me. One example - read (again) my #743 and in particular first linked to article.
    If you can offer a clear refutation along the same lines I have challenged QuarkHead to supply in #752, go for it!
     
  19. James R Just this guy, you know? Staff Member

    Messages:
    35,782
    Q-reeus:

    Let's agree, for the sake of argument, that you have ruled out one suggested scenario for abiogenesis.

    How do you manage to get from there to the conclusion that abiogenesis is impossible?
     
  20. Q-reeus Valued Senior Member

    Messages:
    4,167
    All modern life is cellular. That means having at least a cell membrane and often a cell wall too. So if unguided abiogenesis is true it's essential to explain how a cell membrane could arise by chance processes. I and the author I linked to have argued that is an impossibility. That single failure therefore scuttles the entire edifice of unguided abiogenesis.
    There are many other aspects that are just as problematic, but the issue of cell membrane is imo particularly clear once the conundrum is thought through logically.
     
  21. James R Just this guy, you know? Staff Member

    Messages:
    35,782
    Okay. But nobody is saying chemistry is due to chance, are they?

    While your author might be able to say that Process A can't occur, and processes B and C, there's no possible way your author could rule out all conceivable chemical processes.
     
  22. Q-reeus Valued Senior Member

    Messages:
    4,167
    I made it clear whatever 'chemical processes' are required to transform a simple goo bubble i.e. homogeneous lipid bilayer into a sophisticated *integral* cell membrane, have absolutely zero chance of occurring during the brief lifetime of a freak accident bubble encapsulated 'self-replicator complex'. No Darwinian evolutionist could justify such natural miracles.
    It's as I wrote in #741.
    The challenge remains for YOU to show how it's feasible for such a dramatic transformation to occur in one primitive bubble encapsulated cell lifetime. That miracle is essential if unguided abiogenesis is true.
     
  23. iceaura Valued Senior Member

    Messages:
    30,848
    Yep. That's why Darwinian theory was such a profound advance - that situation is common in biological development, and so far the only theory that agrees with the facts is Darwin's.
    ? Another example of the rule of thumb: in my experience, nobody who dismisses Darwinian theory understands it.

    Straighten out the vocabulary and confused viewpoint (the language always falls apart with these guys), and we have something like "Darwinian theory could never explain this kind if complexity". That is: this is the irreducible complexity argument, which has been debunked to the point of becoming a joke.

    Darwinian theory excels at explaining the evolution of complexity, partly due to its reliance on many highly likely steps instead of one highly unlikely step, partly due to its dismissal of purpose or role (nothing is irreducibly complex if it has no prior assigned role or purpose.)

    Darwinian theory has become the central theory of biology because it handles exactly that situation in ways that match all the physical evidence we have.
    Not regarding abiogenesis. Before there are living beings there are no lifetimes, no cells, none of that stuff. For all anyone knows there were billions of those abiotic bubbles and they were immortal - that's more plausible than a replicating cell existing before there were living beings.
     

Share This Page