A Simpler Origin for Life

The sudden appearance of a large self-copying molecule such as RNA was exceedingly improbable. Energy-driven networks of small molecules afford better odds as the initiators of life.















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(4) A chemical network must be formed, to permit adaptation and evolution. We come now to the heart of the matter. Imagine for example that an energetically favorable redox reaction of a naturally-occurring mineral is linked to the conversion of an organic chemical A to another one B within a compartment. The favorable, energy releasing, entropy-increasing reaction of the mineral drives the A-to-B transformation. I call this key transformation a driver reaction, for it serves as the engine that mobilizes the organization process. If B simply reconverts back to A or escapes from the compartment, we would not be on a path that leads to increased organization. By contrast, if a multi-step chemical pathway--say, B to C to D to A--reconverts B to A, then the steps in that circular process (or cycle) would be favored because they replenish the supply of A, allowing the continuing discharge of energy by the mineral reaction.

If we visualize the cycle as a circular railway line, the energy source keeps the trains traveling around it one way. Each station may also be the hub for a number of branch lines, such as one connecting station D to another station, E. Trains could travel in either direction along that branch, depleting or augmenting the cycle's traffic. Thanks to the continual depletion of A, however, material is drawn from D to A. The resulting depletion of D in turn tends to draw material from E to D. In this way, material is "pulled" along the branch lines into the central cycle, maximizing the energy release that accompanies the driver reaction.

The cycle could also adapt to changing circumstances. As a child, I was fascinated by the way in which water, released from a leaky hydrant, would find a path downhill to the nearest sewer. If falling leaves or dropped refuse blocked that path, the water would back up until another route was found around the obstacle. In the same way, if a change in the acidity or in some other environmental circumstance should hinder a step in the pathway from B to A, material would back up until another route was found. Additional changes of this type would convert the original cycle into a network. This trial-and-error exploration of the chemical "landscape" might also turn up compounds that could catalyze important steps in the cycle, increasing the efficiency with which the network utilized the energy source.

(5) The network must grow and reproduce. To survive and grow, the network must gain material at a rate that compensates for the paths that remove it. Diffusion of network materials out of the compartment into the external world is favored by entropy and will occur to some extent, especially at the start of life when the boundary is a crude one established by the environment rather than one of the highly effective cell membranes available today after billions of years of evolution. Some side reactions may produce gases, which escape, or form tars, which will drop out of solution. If these processes together should exceed the rate at which the network gains material, then it would be extinguished. Exhaustion of the external fuel would have the same effect. We can imagine, on the early Earth, a situation where many startups of this type occur, involving many alternative driver reactions and external energy sources. Finally, a particularly hardy one would take root and sustain itself.

A system of reproduction must eventually develop. If our network is housed in a lipid membrane, then physical forces may split it, after it has grown enough. (Freeman Dyson has described such a system as a "garbage-bag world" in contrast to the "neat and beautiful scene" of the RNA world.) A system that functions in a compartment within a mineral may overflow into adjacent compartments. Whatever the mechanism may be, this dispersal into separated units protects the system from total extinction by a localized destructive event. Once independent units were established, they could evolve in different ways and compete with one another for raw materials; we would have made the transition from life that emerges from nonliving matter through the action of an available energy source to life that adapts to its environment by Darwinian evolution.



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  1. 1. Marco Maga 06:21 PM 11/30/07

    Homeopatics as an Energy Network -
    One can conjecture that as in the human body just one germ can produce a large colony, also really
    small quantities of homeopatic moleclules "reproduce" to larger amounts in cells and tissues (energy networks).

    May be only just for small times but enough to induce health
    benefits.

    hope to hear your opinions

    Marco Magagnini, Ph.D - Milan

    --
    Edited by Marco Maga at 12/03/2007 11:05 AM

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  2. 2. benmoto 04:12 PM 1/18/08

    Do you see prions, which are arguably heritable material in the absence of nucleic acids, as supporting the theory of metabolism first?

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  3. 3. jolly_devil 11:39 AM 3/5/08

    This is my opinion of life:

    Our universe is like a rugby ball and v r just a dot moving across it from the starting point of the Big Bang n now it's moving towards the end of the universe at an accelerating pace (Dark forces). There is an evidence of the accelerating Dark Forces by some of the scientists' observation: the Milky Way Galaxy is getting apart from the nearest galaxy (Andromeda) at an increasing distance. But im not that agree wif this comment. The reason of our galaxy is getting further apart wif the other galaxy may be due to differences in masses. The Andromeda Galaxy may has a higher mass than our Milky Way n since both of the galaxy is moving in the vacuum condition, it will result in an increasing interval of distance.

    (Assume there's a multiverse)
    When the galaxies is moving toward the end of the universe, everything will move faster n faster in the vacuum condition n results in the speed of greater than light. When this occurs, an extremely high gravitivity forces created and then everything will move in a slow pace n crushed into a single point like a melting pot. Wat will happen next? A massive blackhole will be created n everything like our galaxy will be sucked into it and causes a new Big Bang in the other dimension of universe. There it goes, everything starts again in the new dimension of universe! If this is true, life is just like a cycle. We will bcome ourselves again for infinitive times!

    My conclusion is: Life is not simply created for no reason so as the Big bang theory. Everything is not simply pop out or exist for no reason! If those DNA n RNA theories of origin of life r used to prove the creation of life, it may make sense. But it's still not enuf evidences to prove "why u r you, not me?" "why i am myself, not u?"... There's no such answer yet till now on the scientific aspect. If u r not convinced wif the above statement, be optimistic. If u r given life for being u now, there will be another time that u will be given life again to become other things else!

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  4. 4. prkamalnair 11:35 AM 7/31/08

    prions are know to assume the beta amyloid structure.......and they are NOT SELF Replicated.When there is pressure with normal proteins...the normal ones turn into the amyloid form.(Thats not what you call self..is it?)

    I consider them as malformed proteins that did not get eliminated because of their ability to convert normal proteins to amyloid form.

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  5. 5. Dov Henis 10:47 PM 8/31/08

    Life's Manifest

    Recapitulation of some earlier notes on
    The Drive, Nature And Purpose Of Life: Scientific Comprehension

    http://www.physforum.com/index.php?showtopic=14988&st=195&#entry330517


    A. Uniqueness Of science among human artifacts

    ALL aspects of our culture are, of course, anthropoartifacts, including science. Yet among those artifacts science has a distinct uniqueness for us.

    During the recent several centuries in the course of human history humans have been developing science at an accelerating rate as a provider of convincing, ever closer approaching, approximate models of the real world.


    B. The drive and nature of life

    The drive of life and of its evolution is to enhance the functionality and survivability of the genes, in order to maintain and enhance Earth-biosphere's temporary constrained energy storage and to maintain it BIO as long as possible.

    It is the genes, life's prime strata organisms, that evolve, and the evolution of genomes, the 2nd stratum of life, and of the 3rd life stratum cellular organisms, is an interenhancing consequence of their genes' evolution.


    C. The nature of life

    Earth Life: 1. a format of temporarily constrained energy, retained in temporary constrained genetic energy packages in forms of genes, genomes and organisms 2. a real virtual affair that pops in and out of existence in its matrix, which is the energy constrained in Earth's biosphere.

    Earth organism: a temporary self-replicable constrained-energy genetic system that supports and maintains Earth's biosphere by maintenance of genes.

    Gene: a primal Earth's organism. (1st stratum organism)

    Genome: a multigenes organism consisting of a cooperative commune of its member genes. (2nd stratum organism)

    Cellular organisms: mono- or multi-celled earth organisms. (3rd stratum organism)


    D. Update of underlying life sciences conception is thus feasible

    - First were independent individual genes, Earth's primal organisms.

    - Genes aggregated cooperatively into genomes, multigenes organisms, with genomes' organs.

    - Simultaneously or consequently genomes evolved protective and functional membranes, organs.

    - Then followed cellular organisms, with a variety of outer-cell membrane shapes and
    functionalities.

    This conception is a scientific, NOT TECHNOLOGICAL, life-science innovation.

    It is tomorrow's comprehension of life and of its evolution.

    IT IS FRAUGHT WITH INTRIGUING DARWINIAN EVOLUTION IMPLICATIONS.

    IT IS FRAUGHT WITH INTRIGUING TECHNOLOGICAL DEVELOPMENTS POTENTIALS.


    E. The purpose of OUR, human, life

    The purpose of OUR life and its promotion is ours to formulate and set. It derives solely from our cognition.


    Suggesting,

    Dov Henis

    http://blog.360.yahoo.com/blog-P81pQcU1dLBbHgtjQjxG_Q--?cq=1



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  6. 6. sk8rdy 12:09 AM 9/15/08

    Very informative article when it comes down to understanding the way proteins are a functional unit in life.

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  7. 7. MEch 04:38 PM 10/21/08

    So far the best alternative hypothesis I've read on the topic of life's origins.

    I have a suggestion for testing this hypothesis with experiments: it is probably safe to assume that our planet has been on a 24 hour cycle due to it's rotation and the distance from the sun probably hasn't changed much; the sun probably contributed to numerous UV or heat induced reactions on the Earth's surface. Most living things on this planet adhere to the 24 (+variation) hour cycle, the circadian rhythm (with the exception of some cyanobacteria and deep sea species, not sure about this). there are probably many slow-acting reactions, i.e., those with roughly a 24 hour cycle that can be tested in the lab for a cyclical pattern. In fact, they do not have to be 24 hours to test the stated hypothesis given that any cycle can lead to the development of an organized pattern. Given that this state of the planet's environment probably hasn't changed drastically (e.g., from a 100 hour day), it is probable that the earliest cycles were 24 hour based.

    comments welcome.
    MEch

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  8. 8. chavidorjr 01:03 PM 11/8/08

    -origin of life huh, i don't know but writing and assignment on this really helped me out to grasp the concepts of the requirements of life and the difference between "small molecules" that might have started life or "RNA first". Long article but got a point across....

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  9. 9. jcaiken in reply to MEch 08:57 PM 10/20/09

    I wonder how the history of the Solar System and the Earth/Moon pair could colour our understanding of this process.

    I would expect the frequent, violent tides of hot water during the early life of the Earth,when the Moon was very close and the Earth was cool enough for water to condense and accumulate, would provide an vigorous environment for rapid evolution and distribution of the chemical building blocks for 'life'. But would the level of complexity that could develop at that time be constrained by these same conditions.

    The latest theories seem to suggest that both the large, influential moon and the water arrived on the Earth by impact. What are the chances of this happening in such a way and at such a time that they were not absorbed or distributed, but remained localised enough to have the observed impact on the Earth.

    Could the resulting conditions and their impact on 'life' be so rare as to be almost unique?
    How would life have developed without the mixing & distribution possible in a large body of well-stirred, hot, volitile liquid? Could it have survived an "extinction-event" meteor impact, for example?

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  10. 10. Dov Henis 02:53 PM 1/10/10

    Unbelievable! Origin Of Life Pre-Metabolism?
    The Wheel has Just Been Reinvented!
    Read All About It!


    What Came First in the Origin of Life? New Study Contradicts the 'Metabolism First' Hypothesis
    http://www.sciencedaily.com/releases/2010/01/100108101433.htm


    Dov Henis
    (Comments From The 22nd Century)
    Updated Life's Manifest May 2009
    http://www.the-scientist.com/community/posts/list/140/122.page#2321
    28Dec09 Implications Of E=Total[m(1 + D)]
    http://www.the-scientist.com/community/posts/list/184.page#4587
    Cosmic Evolution Simplified
    http://www.the-scientist.com/community/posts/list/240/122.page#4427


    PS: Just reflect about sleep and chirality... DH

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  11. 11. Skepto 07:23 PM 7/1/10

    I am surprised that this research has not yet attracted a mass of religious zealots who are horrified that humans are trying to take over God's primary feat - the creation of life. This hubris can result in nothing less than what happened to those who constructed the Tower of Babel, stuff like that. Anyway, I hope I live to see my fellow humans achieve this goal. For now, I carry a card in my wallet that says: I am an atheist. In case for accident call a doctor

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