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Thread: What caused life to form on planet Earth to allow evolution?

  1. #1 What caused life to form on planet Earth to allow evolution? 
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    inow; I hope you don't mind me introducing a new thread, rather than beating up on a Religious Topic. Besides there are more knowledgeable folks here, that would be happy to cut my ideas to shreads...

    inow quote; answering my comment; "An interesting thought and one I've wondered about. Either living cells formed in vast amounts from some event or process or how could they have survived. Nutrition must have been needed and I'm not aware of anything living, surviving off inorganic material alone."

    Again... It really depends on how you define "nutrition." It's just basic chemistry which was taking place. Is it "nutrition" when two hydrogen molecules join with an oxygen molecule to form water? I really struggle to understand why this is so hard for folks. It's amazing what tiny changes can lead to over extremely long time periods such as those involved with this question.
    .

    Life as we accept the word or ALL living things, trees, grass, humans to those very complex single cell organisms, need some form of nutrition to survive, much less reproduce in order to eventually evolve. I didn't even address the more complex comment, that you believe life will someday be produced by mankind, which I'd question. First, I don't believe conditions needed can be devised, even if 'hydrothermal vents' are the answer. Second, the incredible complexity of micro-organism, should mean a rather complex process, which may not ever be understood, much less duplicated.

    Hydrothermal origin of life
    Günter Wächtershäuser proposed the Iron-sulfur world theory and suggested that life might have originated at hydrothermal vents. Wächtershäuser proposed that an early form of metabolism predated genetics. By metabolism he meant a cycle of chemical reactions that produce energy in a form that can be harnessed by other processes.[14]
    It has been proposed that amino-acid synthesis could have occurred deep in the Earth's crust and that these amino-acids were subsequently shot up along with hydrothermal fluids into cooler waters, where lower temperatures and the presence of clay minerals would have fostered the formation of peptides and protocells.[15] This is an attractive hypothesis because of the abundance of CH4 and NH3 present in hydrothermal vent regions, a condition that was not provided by the Earth's primitive atmosphere. A major limitation to this hypothesis is the lack of stability of organic molecules at high temperatures, but some have suggested that life would have originated outside of the zones of highest temperature. There are numerous species of extremophiles and other organisms currently living immediately around deep-sea vents
    http://en.wikipedia.org/wiki/Hydroth...origin_of_life

    As for 'panspermia hypothesis', I totally agree and the reason I mentioned the fact I would argue with the article, however his point, that potential life producing materials should be abundant throughout the Universe, I would agree. Under BBT, our star and related matter (a fraction of the total .15%) is at least a second, maybe third generation result. Since we're well with in the Milky Way Galaxy, the probability is we formed, in part from former stars or the dust from the MW that made in to one of the many Molecular Clouds, Giant MC or Nebula, not likely from materials originating elsewhere in the Universe.


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    Forum Cosmic Wizard i_feel_tiredsleepy's Avatar
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    It's called autotrophy, it is what ecosystems are based on, it wouldn't be sustainable for all organisms to be heterotrophic. Energy conversion from eating another organism is not 100% efficient, so without some form of external energy source (like inorganic compounds or the sun) an ecosystem based solely on heterotrophs eating each other would inevitably die out.

    Now in time many organisms have evolved to become only partially autotrophic. Plants rely on ammonia produced by bacteria in the soil to survive. The first organisms would have been completely autotrophic.


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  4. #3  
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    Quote Originally Posted by i_feel_tiredsleepy
    The first organisms would have been completely autotrophic.
    As relating to other organisms, but not completely. Only stars are complete autotrophs, because
    Quote Originally Posted by jackson33
    we formed, in part from former stars
    'Else it's all just hydrogen without gradient.
    A pong by any other name is still a pong. -williampinn
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  5. #4  
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    i_feel_tired; Thank you for your site, http://en.wikipedia.org/wiki/Lithotroph frankly I wasn't aware of' 'Lithotrophs', at least the idea of feeding off rock.

    Autotrophy is the ability to be self-sustained by producing food from inorganic compounds. Some bacteria and some archaea have this ability. Inorganic compounds are oxidized directly without sunlight to yield energy. This metabolic mode also requires energy for CO2 reduction, like photosynthesis, but no lipid-mediated processes are involved. This metabolic mode has also been called chemotrophy, chemoautotrophy, or chemolithotrophy. Carbon autotrophy is the ability to assimilate CO2 from the air. Nitrogen autotrophy is the ability to assimilate nitrate or to do nitrogen fixation. Sulfur autrophy is the ability to assimilate sulfate (sulfur assimilation).
    http://en.wikipedia.org/wiki/Autotrophy

    VERY interesting and answers my question. Also it gives another reason why those first micro-organisms and there ancestors were/are so complex. They self PRODUCED food or the nourishment from inorganic material. That makes sense...
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  6. #5  
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    Quote Originally Posted by jackson33
    VERY interesting and answers my question. Also it gives another reason why those first micro-organisms and there ancestors were/are so complex. They self PRODUCED food or the nourishment from inorganic material. That makes sense...
    Most of the reactions they listed in that wikipedia aren't particularly complex. Getting energy by oxidizing Fe2+ to Fe3+ or reducing sulfate to sulfite isn't very complicated...
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  7. #6  
    Forum Cosmic Wizard i_feel_tiredsleepy's Avatar
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    These systems function pretty much the same as any electron transport chain. In fact, they are less complicated than the eukaryotic method. In eukaryotes we oxidize glucose and produce reduced NADH, which is then oxidized to reduce oxygen to water.

    Eukaryotic energy production is much more complicated because it involves several intermediate reactions and compartmentalization. Not to mention we are capable of oxidizing fats, alcohol, proteins, fructose, galactose, and glucose. Each of those requires a separate set of enzymes and pathways. It's more complicated being a heterotroph because you have to be versatile.

    In a nitrifying bacteria they don't produce any intermediates, they just directly oxidize the ammonia or nitrite and send the electrons off down the chain to oxygen.

    Source: Lengeler, Joseph et al. Biology of the Prokaryotes. 1999.

    (text getting a bit outdated but this book cost me like 250 dollars T_T)
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    SR & IFT; You taking me back to my original problem, when mentioning simplicity to the operation of a single cell organism, understanding a little about the differences in those creatures today and a single human cell.

    In order for the process to get programed into those first cells DNA, your talking eons and untold generations of failures, complex or not, I would think. It's not so much the generations, but these could not have been spontaneous natural reactions to some combination of events, but rather an ongoing process which if figured out, could be duplicated. Creating conditions would be a different story, if for no other reason than exact potentials for conditions leading to events on earth 4BYA or so may never be understood.
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    Forum Cosmic Wizard spuriousmonkey's Avatar
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    Evolution doesn't care about waste. In fact waste is fine if it is affordable.

    Hence we have trees. Do you not think it is a big waste to build a huge structure of wood just to elevate your leaves. There isn't more sun up there as there is on the floor.

    They do it because they are in competition with other trees. They don't grow higher because at one point the waste becomes unaffordable.

    So don't see waste as a problem. It is an integral part of an evolutionary system.

    What matters is that there should be inherited variation. That's all.

    Complexity is build on existing complexity.

    Eukaryotes incorporate prokaryotes (mitochondria and chloroplasts) and can grow in complexity.

    The key is the presence of heredity in a system and the fact that some of the hereditary determined molecules act better than others under certain conditions.

    It doesn't have to be perfect. Minimal increase in performance will have huge benefits in a population of simple replicating 'machines'.
    "Kill them all and let God sort them out."

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    SM; Certainly not claiming expert status, I basically understand Evolution, that 99++% of all species that have ever existed have failed (died off), yet there a millions of species remaining on this planet today.

    In short, what I am trying to explore here are ideas on how that first living cell came into existence, that lead to that evolution. From the article I'm referencing;

    Supernatural creation - God or some other supernatural power. These examples do simplify the requirements for the "original cell," but it is still a long way to spontaneous generation of life. Perhaps the first living cells were completely different from what we see today, and no one has yet imagined what they might have been like. Speaking in general terms, life can only have come from one of two possible places:

    Spontaneous creation - Random chemical processes created the first living cell.
    Supernatural creation - God or some other supernatural power
    What I am wondering about is the word 'Spontaneous', in considering the word Natural or a natural process in the formation of inert matter, in the first place or that evolution itself as understood, begins during the process of all Star formations, THEN circumstances, environmental condition and so on, lead on to the formation of living cells. If life had never formed on this planet, and I suspect dead planets in our solar system, the chemicals, elements and required things needed would be there or had been, anyway. As for supernatural, I have all kinds of problems with that idea, God, Aliens or transport via meteors or any of the theory.

    http://science.howstuffworks.com/evo...volution11.htm

    To further understand where I'm going, here is a summery of elements, including those required for life as we describe what is actually life, with the exception of Hydrogen (found every where) are produced by solar activity.

    The elements which compose living things are called the organic elements. The organic elements can be remembered by this pneumonic devise: C Hopkins CaFe Mg NaCl.
    1. C=carbon 2. H=hydrogen 3. O=oxygen 4. P=phosphorus
    5. K=potassium 6. I=iodine 7. N=nitrogen 8. S=sulfur
    9. Ca=calcium 10. Fe=iron 11. Mg=magnesium 12. Na=sodium
    13. Cl=chlorine
    While these are the main elements which compose living things, but not the only elements which compose living things.
    http://us.geocities.com/j31645/13.html
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  11. #10  
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    Here are a couple of points that may be relevant to your question Jackson.

    Firstly, as may already have been mentioned, the earliest cells were almost certainly much simpler than the simplest of cells that exist today.

    Secondly, there was a great deal of pre-biotic chemistry going on before life arose. In an environment in which there was no life there was a unique opportunity for complex molecules to build up over time to produce the primeval soup.Today any such molecules would be instantly gobbled up as food.

    Thirdly, that pre-biotic chemistry almost certainly included self sustaining auto-catalytic cycles. In other words chemical pathways existed from one to another chemical that were encouraged by one or more chemicals within that same chain.

    Fourthly, we think of life and non-life, as though this was a digitial choice. It isn't. Life is analog. There is a spectrum from life ot non-life and where we cross from one to the other is really a matter of wording, not true meaning.
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    Ophie;
    My discussion is based on the idea, that the first hundred quadrillion or so events created nothing more than a sub-living combination of inert (dead) matter, that at some point a cell did survive long enough to reproduce (divide) a time or several times and evolution began. The complexity of those that first survived, would have to had been enough to overcome what ever had been a resistance to that survival, I believe very complex. The point of discussion, if possible on a hypothetical scenario/hypothesis, is that this indicates an ongoing process, not spontaneous anything which basically is Abiogenesis.

    Possibly, in my ignorance, I am trying to claim Abiogenisis and Panspermi were both involved or at least the idea all the ingredients for life itself are common, though out the Universe and was on earth, during some critical point, when the "pre-biotic chemistry" was advantageous to that formation.

    In referencing another site on the topic, I need to mention my non acceptance of Creationism, divine intervention or introduction from other life forms. You referenced salinity, I like to use the genetic structure, which ALL living things have some of all other living things in their structure. However, I should mention the argument, that if life was introduced to planet Earth, it would have evolved, producing the same results.

    The cell is the atom of life. If disrupted it dies. It is extremely complex. This complexity is conserved as such and passed from generation to generation. The first cells which appeared on earth were the archaea. They lack a nucleus and are called also prokaryotes. Then some invaded other cells, continued living in their cytoplasm, and became cell organelles, like mitochondria. (v. Lynn Margulis http://www.bio.umass.edu/faculty/biog/margulis.html ). In the same way cell nuclei were formed in eukaryotes.
    http://forum.wolframscience.com/arch...pic/245-1.html

    Initially, archaea were seen as extremophiles that lived in harsh environments, such as hot springs and salt lakes, but they have since been found in a broad range of habitats, such as soils, oceans, and marshlands.
    http://en.wikipedia.org/wiki/Archaea

    By the way, I totally agree with "Fourthly", mentioned in my previous post....
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  13. #12  
    Forum Cosmic Wizard spuriousmonkey's Avatar
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    What caused life to form on planet Earth to allow evolution?

    Tautology.

    There is no life as we know it or known it without evolution.
    "Kill them all and let God sort them out."

    - Arnaud Amalric

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  14. #13  
    Universal Mind John Galt's Avatar
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    Quote Originally Posted by jackson33
    Ophie;
    My discussion is based on the idea, that the first hundred quadrillion or so events created nothing more than a sub-living combination of inert (dead) matter,....
    Except that this matter was not inert. It was chemically very active. Moreover some of these reactions were the same as ones that occur in organisms today and that constitute part of the phenomenom of life.
    Further, the point at which we move from chemically active systems to a system we are prepared to call life is subjective. In truth there is no point at which the transition occurs, but rather a range of complexities.
    Quote Originally Posted by jackson33
    that at some point a cell did survive long enough to reproduce (divide) a time or several times and evolution began. ....
    Most biologists who work in the area of abiogenesis would argue, I think, that there is a form of evolution at work on the pre-biotic chemistry. Chemical pathways that are autocatalytic are naturally favoured over those that are not. The more efficient the pathway the more likely it is to dominate in the primeval soup over other reactions that use the same root material.
    Quote Originally Posted by jackson33
    The point of discussion, if possible on a hypothetical scenario/hypothesis, is that this indicates an ongoing process, not spontaneous anything which basically is Abiogenesis.....
    Spontaneous generation is used today to mean life arising out of non-life, but not life arising fully formed, fully functioning, in an instant, out of non-life. All the researchers I have read, whether in popular works or in research papers see abiogenesis as you seem to see it, as a process.
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    WYSIWYG Moderator marnixR's Avatar
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    i think i perceive a common misconception here
    when people have a problem with "inert material" turning into life, they think of something pretty stable like sand coming alive, whereas you should really compare it with the diversity available in the realm of organic chemistry

    once you've taken this conceptual leap, the step from non-life to life does not seem as insurmountable
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
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  16. #15  
    Forum Cosmic Wizard spuriousmonkey's Avatar
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    Life is just a collection of non-life stuff with a touch of holism.
    "Kill them all and let God sort them out."

    - Arnaud Amalric

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  17. #16  
    WYSIWYG Moderator marnixR's Avatar
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    Quote Originally Posted by spuriousmonkey
    Life is just a collection of non-life stuff with a touch of holism.
    holy mackerel, batman ! life equates non-life with a halo ?
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
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  18. #17  
    Forum Cosmic Wizard icewendigo's Avatar
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    Quote Originally Posted by Ophiolite
    Quote Originally Posted by jackson33
    Ophie;
    My discussion is based on the idea, that the first hundred quadrillion or so events created nothing more than a sub-living combination of inert (dead) matter,....
    Except that this matter was not inert. It was chemically very active. Moreover some of these reactions were the same as ones that occur in organisms today and that constitute part of the phenomenom of life.
    Further, the point at which we move from chemically active systems to a system we are prepared to call life is subjective. In truth there is no point at which the transition occurs, but rather a range of complexities.
    Quote Originally Posted by jackson33
    that at some point a cell did survive long enough to reproduce (divide) a time or several times and evolution began. ....
    Most biologists who work in the area of abiogenesis would argue, I think, that there is a form of evolution at work on the pre-biotic chemistry. Chemical pathways that are autocatalytic are naturally favoured over those that are not. The more efficient the pathway the more likely it is to dominate in the primeval soup over other reactions that use the same root material.
    Quote Originally Posted by jackson33
    The point of discussion, if possible on a hypothetical scenario/hypothesis, is that this indicates an ongoing process, not spontaneous anything which basically is Abiogenesis.....
    Spontaneous generation is used today to mean life arising out of non-life, but not life arising fully formed, fully functioning, in an instant, out of non-life. All the researchers I have read, whether in popular works or in research papers see abiogenesis as you seem to see it, as a process.
    Agreed

    From hydrogen, to hydrocarbons(Titan has seas of hydrocarbons), to Organic molecules composed primarily of the most aboundant elements such has hydrogen, carbon and oxygen(also observed in outer space), to more complex chains and structures that existed prior to life, we see that there are building blocks that assemble themselves from more basic blocks in some environments over a period of time, the universe is huge and has a variety of changing environments some favorable other not to added compexity in structure and interaction. Inertness and life are harder to understand if you see these as Black and White, but easier to understand if you see them as shades of grey (virus and organelles are also easier to understand from this perspective)
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  19. #18  
    Forum Cosmic Wizard spuriousmonkey's Avatar
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    The general view on the origins of life is polluted by the fact that currently many lifeforms are actively 'cleaning' up organic mess.

    Hence we don't really appreciate a state of organic chaos chemistry that once was.
    "Kill them all and let God sort them out."

    - Arnaud Amalric

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