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Evolution did not start life

  1. Feb 13, 2016 #1
    Many people have claimed that evolution started life. I'd say it did not. Life started evolution. Before there is evolution, there must be life. Am I right?
     
  2. jcsd
  3. Feb 13, 2016 #2

    DaveC426913

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    Who has claimed evolution started life?
    They are ignorant.
     
  4. Feb 13, 2016 #3

    berkeman

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    Interesting discussion -- the Mentors are watching this thread... :smile:
     
  5. Feb 13, 2016 #4

    Evo

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    Let's not confuse abiogenesis (the start of life) and evolution. They are not the same.

    http://www.universetoday.com/41024/abiogenesis/

    To keep this within known, accurate science, if you post, you will need to post your source which is acceptable accordng to our guidelines..
     
    Last edited: Feb 13, 2016
  6. Feb 15, 2016 #5
    It all depends on how you define evolution, if you think of it as the way things might change or develop it could mean lots of things. Its often better to talk about biological evolution which is far more specific and everyone knows what being, discussed. Most dictionaries provide reasonable sources for this.
     
  7. Feb 23, 2016 #6
    Is that not correct in the sense that (chemical) survival and reproductive success were relevant, crucial, and necessary for the origin of life on earth even during pre-biotic evolution, even before any signs of life existed on earth, and therefore the fundamental tenant of evolution, survival and reproductive success, was necessary for life to emerge on earth, and in this regards, one could suggest, "evolution started life?"
     
  8. Feb 23, 2016 #7
    This begs the question of how to define what is life and what is not.
    From our one example of life on Earth we might say it's life if it's a contained self replicating system driven by DNA, (a cell).
    But we don't know if other kinds of self replication can exist, and even taking the DNA/cell basis as a definition there are viruses, which are not cells and can in some cases consist only of a (relatively) simple package of RNA + proteins.
     
  9. Feb 23, 2016 #8
    I have another question for you OP. Only intelligent life can create information, what created DNA in the first place? the conventional theory of it arising out of a melting pot of ideal conditions.... Even the most basic of DNA, are we really to believe the conventional explanation?
     
  10. Feb 24, 2016 #9

    Drakkith

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    This is incorrect. Information: At its most fundamental, information is any propagation of cause and effect within a system.
    Clearly this is occurs in non-living systems all the time.

    No flawed information has been posted. Biogenesis is not a theory on the origin of life and never has been (as the wiki article you posted yourself explains).
     
  11. Feb 24, 2016 #10
    Creationists are the ones insisting the intimate coupling of life origin with evolution. They say, you can't know evolution if you don't know beginnings, then they inevitably start the 'let there be light' bit.....
     
  12. Feb 24, 2016 #11
    OK I agree, it's a hypothesis that says life can be created from non-living materials.
    Why do you say so ?
    Louis Pasteur's experiment supports the hypothesis of biogenesis. So I don't see the point as to why you turn it down as a "hypothesis" of life origin.
     
  13. Feb 24, 2016 #12
    Essentially the term 'biogenesis' in it's modern context, (as defined by Huxley, referenced above), is more or less a synonym for 'evolution' - lifeforms arise from ancestor lifeforms.
    Except that it doesn't infer 'natural selection', which usually is the implication nowdays when when we speak of 'evolution' of life.
    Abiogenesis is a proposal (actually there are a few different ones) for the origin of all life, 'biogenesis' (not a frequently used term anyway), does not propose an origin.
     
    Last edited: Feb 24, 2016
  14. Feb 24, 2016 #13
    I understand why someone might see a connection between Pasteur's experiment and a disproof of abiogenesis, but this misconception arises from a failure to understand what it was that Pasteur's experiment was designed to attempt to disprove and what it was not designed to attempt to disprove. The nineteenth-century hypothesis of spontaneous generation and the modern hypothesis of abiogenesis might seem very similar, but they are distinct and should not be confused.
    From https://en.wikipedia.org/wiki/Spontaneous_generation: "Spontaneous generation refers both to the supposed processes in which different types of life might repeatedly emerge from specific sources other than seeds, eggs or parents, and also to the theoretical principles which were presented in support of any such phenomena. Crucial to this doctrine is the idea that life comes from non-life, with the conditions, and that no causal agent is needed (i.e. Parent). Such hypothetical processes sometimes are referred to as abiogenesis, in which life routinely emerges from non-living matter on a time scale of anything from minutes to weeks, or perhaps a season or so. An example would be the supposed seasonal generation of mice and other animals from the mud of the Nile.[7] Such ideas have no operative principles in common with the modern hypothesis of abiogenesis, in which life emerged in the early ages of the planet, over a time span of at least millions of years, and subsequently diversified without evidence that there ever has been any subsequent repetition of the event."
     
  15. Feb 24, 2016 #14

    Drakkith

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    Mindwalk explained it better than I ever could. The theory of biogenesis, as tested by Louis Pasteur, was developed as a competing theory to spontaneous generation, not as an explanation of where all life originally came from, which is what has been proposed in this thread.
     
  16. Feb 25, 2016 #15
    this thread is clearly very confusing.. anyone who thinks evolution started life is WRONG. Evolution came after life! So that would be very ignorant. Also it is difficult to actually know when evolution is occurring, say, is it just a mutation/change in gene/allele (forgot which term)..I would say its much easier to judge from context and effect. Evolution can take thousands of years or decades..I only studied a level biology but its not that hard to realise its a bit relative.

    secondly, of course only life can create other life, BUT we want to know what and how created the first ever life form and that is something no one has been able to prove convincingly. There are certain 7 characteristics of life forms from what I remember in A level biology (I dont remember everything well):

    1. respiration
    2. Movement
    3. growth (an increase in dry mass?) (?)
    3. Excretion
    4. ability to sense environment/changes in environment.
    5. Most important ability to reproduce

    Now there is also a debate on how to define this basic criteria itself..some say a virus is non living but others say it isn't as it is just a collection of RNA. So there are many problems, as to my point of intelligent life only being able to create the hyper detailed instructions known as DNA, well... The funny thing is, we don't even know what came first! the DNA or the organism/structure that produces it (ribosomes).

    So what would be the first ever, "life" form? no doubt one general consensus would say some ancient micro organism.. But HOW did that come into existance? No one has been able to conclusively tell and anyone who claims otherwise is simply wrong.

    Why is it important to know? because the answer could very well tell us the purpose of "life" or of our percieved existance as well. Some say living organisms are just vessels for DNA's survival.. the reason they exist is so DNA CAN has been proposed.

    What are the theories? ( I am listing all I have come across) NOTE: I AM LISTING NOT SUPPORTING ANY, these are all including out of the realm of mainstram science..but it is important to know!

    1. God (most popular amongst the human population)

    2. Natural processes leading to a perfect ideal conditions, causing the building blocks of life to form..which led to life (most popular in scientific community) (very logical theory, and I also believe this but need to see more evidence)

    3. Otherworldy beings created us (even as a simulation can fit in here) and left easter eggs in the form of pyramids/stonehenge/easter island...(Popular amongst crackpots like myself, but is number one different from 3?) (a theory discussed by some physicists, really not mainstream science)

    so all in all, any discussion on the origins of life has very deep significant meaning for all of us, but evolution did not start life, evolution is the result of life processes.
     
    Last edited: Feb 25, 2016
  17. Feb 25, 2016 #16
    The dynamics necessary for the origin and evolution of life existed before life and are independent of life. The inconsequential trappings of biology and chemistry instantiating life on earth are just happenstance and convenient for our particular planet. Consider a concrete example: termite mounds. Camazine and others have formulated a coupled system of PDEs modeling the dynamics between termite, mud, and pheromone. The marvelous clay cathedral "emerges" not because of some termite blue-print a master termite is following, but rather entirely because of non-linear dynamics. Then on a more fundamental level, the mud, pheromone, even the termite becomes irrelevant; we could just as well replace them with marbles, pencils, and paperclips behaving in the same dynamic way and a mound (pencil perhaps) would still emerge! The same could be argued with many other biological systems on earth according to Camazine's book "Self-Organization in Biological Systems," and therefore I do not believe it is an unreasonable stretch of logic to suggest the same may or could be said about the origin of life itself: the dynamics needed for the origin of life to occur existed before life (is timeless) and in this way I argue the "dynamics" of evolution started life on earth.

    Citation: http://press.princeton.edu/titles/7104.html

    Note: In an effort to be rigorous, I should note the PDEs modeling termite behavior cited above where not just "conveniently" constructed to achieve a desired effect but rather, to the best available experimental data, constructed according to the actual physical interactions between termite, mud and pheromone.
     
    Last edited: Feb 25, 2016
  18. Feb 25, 2016 #17
    The simplest self replicating molecule we know of seems to be RNA, as viruses.
    Yet RNA only can do that by taking over the reproductive machinery of more complex cellular organisms.
    It's a puzzle.
     
  19. Feb 25, 2016 #18

    Drakkith

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    I don't think that's true, but I'll have to look around to see if I can find the information on it.
     
  20. Feb 25, 2016 #19

    Drakkith

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    I looked around a bit and found some information primarily on autocatalysis. I'm not sure if this is quite what you meant by your statement, but I would say there are plenty of examples of self-replicating molecules out there.

    Here's a slideshow on a few, most of which are biological molecules: http://www.slideshare.net/bfrezza/selfreplicating-molecules-an-introduction

    Some info from the journal of the american chemical society (behind a paywall unfortunately): http://pubs.acs.org/doi/abs/10.1021/ja00099a003?journalCode=jacsat

    More info on self-replication: http://www.astroscu.unam.mx/~angel/tsb/Rebek.htm
     
  21. Feb 25, 2016 #20
    That is one of the difficulties for people to also consider a pre-RNA (PNA) world. This is an interesting summary about chemicals and pre-life.
    What about experiments to generate or create amino acid sequences from simple chemical elements and compounds e.g NH3, H2, O2, C, etc. in nature ?
    Self-replicating molecules must receive an energy input enough to perform their reactions and replication and at the same time release an amount of energy. Where does the input energy come from ? and what is the output for ?
     
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