Is the planet "broken" and did that cause the evolution of predation?

Discussion in 'Biology & Genetics' started by Wexler, Jun 21, 2015.

  1. billvon Valued Senior Member

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    No - that's how the planet works. And again, you wouldn't be here without those things.
     
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  3. Wexler Gadfly Registered Senior Member

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    No, that's how THIS planet works...you are assuming that this planet is functioning "correctly". You are taking a very Earth-centric point of view, as though there is no possibility of any other type of planetary system out there in the universe...thus why I pointed to all the other "discoveries" that reshaped human perspective; nothing existed until we found it.


    And now back to the original question, who is to say that "we", based on predation pushing evolutionary advancement, are the "right" life form to evolve?

    This is not about being "lucky" to be alive, or if humans would or would not be here without predation...that would be to assume that humans are the "best" thing for this planet...and I am sure we can all agree on that subject.


    Predation is a ubiquitous and powerful agent of natural selection. Is it is driven by a lack of resources? Probably. Where do the resources come from? The environment.

    So, imagine a different solar system, with a different energy source on a different rock with a different environment - think that life on that planet evolves from predatory behavior or not?

    I am inclined to think that if there are balanced, equal resource distribution, over time, there is life and there is some form of advancement that leads to consciousness...without eating each other.
     
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  5. billvon Valued Senior Member

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    Of course and of course.
    ?? No, I am taking the view that Earth works correctly. Io works correctly, even though its surface is a combination of airless vacuum and molten lava. Europa works correctly, even though its surface is completely frozen.

    The only "incorrect" way a planet could work would be to violate the laws of physics. So far we haven't found one that doesn't, and indeed it is unlikely we will.
    We're not "right." We are merely successful.
    You are using a lot of terms that indicate personal preferences from your point of view. "Right?" "Best?" Not really any such thing. (Indeed, if you are using the term "correct" as a moral judgment, as opposed to merely something that works correctly per physical laws, that would also be an invalid personal moral judgment applied to a physical process.)
    Exactly. And every organism without any limits on reproduction will continue to reproduce until those resources are exhausted. (Think yeast.) When that happens, they:
    1) all die. This has happened millions of times in closed environments here, and has undoubtedly happened in the larger world as well.
    2) die off enough that the resources can replenish themselves (if such a thing is possible.)
    3) become prey for another species, and thus return to equilibrium (google predator-prey cycle)
    I imagine there would be time, very early in the existence of life on the planet, where there would be no predatory life. That would change quickly as the organism evolved to use all available resources - including the resources inherent in other organisms.
     
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  7. spidergoat Liddle' Dick Tater Valued Senior Member

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    It is thought that organisms were remarkably stable for millions of years until the rise of free oxygen. No predators to speak of.
     
  8. Wexler Gadfly Registered Senior Member

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    ...billions of years...quite longer than the time cannibalism and predation have been in existence.


    Thus a different energy source could possibly create a different outcome?

    Imagine that.

    And that's the point. A different planet with a different energy source might just produce a different outcome.
     
  9. billvon Valued Senior Member

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    In terms of "resources" I was referring primarily to raw materials.
     
  10. spidergoat Liddle' Dick Tater Valued Senior Member

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    I think you may be right about that. But predators use a lot of energy, it probably took oxygen to stimulate their development. And remember the living things that did exist before then were very plant-like, they didn't move, just sucked nutrients and particles out of the water.
     
  11. Wexler Gadfly Registered Senior Member

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    Good. So now that we are beyond semantics and morality, it gets back to the core issue:

    A planet that has shown a repetitive pattern of behavior of catastrophic events for its inhabitants based on being (insert descriptive word here that you choose, I chose "broken"...) with a relatively mediocre energy source.

    Coincidentally, after each catastrophic event life took a great leap forward in advancement based on a lack of resources and niche's opening up thanks to the catastrophe. It was all triggered by the leap to multicellularity when the ingredients of the primordial soup ran out in combination with life attempting to survive the initial snowball earth...



    Yes, and so this is really a crucial part of the hypothetical; if you believe, as I firmly do, that there is life elsewhere in the universe, and based on the unfathomable amount of potential habitable planets there might just be a planet(s) that have a much larger energy source and in a much more stable environment that are much older than our relatively "young" system.

    You put it all together, and while evolution is undeniable, it is quite likely that while we project predatory behavior upon any other potential life form in the universe, that behavior might just be specific to this planet...based on all those attributes I listed earlier...primarily a lack of resources in an unstable environment.
     
  12. billvon Valued Senior Member

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    Well, now we're back to subjective definition of "catastrophic." The end of the large saurians was catastrophic for them; it was an incredible boon for mammals. Oxygen was catastrophic to most organisms, as was UV.
    But again, "lots of resources" does not mean "therefore life knows when to stop." On a planet of sugar water, yeast will grow until all that sugar is converted to CO2 and alcohol - and then die. And they are pretty simple.

    It sounds like you are equating aggressive environment to aggressive organism or something like that. However, predation did not evolve in response to a hostile environment - it evolved because predators were better suited to their environment than non-predators were. Now, if you are postulating an environment where life began but never started evolving, I agree that we would never see predation. However, that would be meager and simple form of life indeed.
     
  13. Wexler Gadfly Registered Senior Member

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    I am equating a lack of resources and an unstable environment as the perfect platform for predatory behavior in an evolving life form.

    Take molecules that coalesce into becoming living chemistry thanks to an energy source, in an environment that has ample resources and a stable environment and I believe predatory behavior would not exist in that world, but evolution probably will.

    Jeremy England lecture.


    I am also saying that evolution is a natural life force (if you will) of the universe. All life forms (if and when found) will observe the general laws of evolution, but based on the environment they evolved in will dictate if they will eat other organisms or not.
     
  14. exchemist Valued Senior Member

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    I have read this correspondence and I really struggle to see how any significant life can exist without things eating other things. Take an immune system, for example. If you have bacteria and viruses that can poison or disrupt the cells of an organism, the only way it can defend itself is via an immune system, surely? This generally involves cells that ingest, i.e. eat, the invaders. Do you really envisage a form of ecosystem in which none of this exists? Or do you define "predation" more narrowly than this and, if so, what is your definition of it?
     
  15. Wexler Gadfly Registered Senior Member

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    Yes, because we have no idea how long "significant" life in environments other than Earth take to evolve...but we do know that predation did not exist until roughly 600,000,000 years ago...meaning that for the largest span of life, significant or other wise, it was not reflecting any sort of predator vs. prey interaction to stimulate evolution.

    One could argue that life on this planet would not have evolved and advanced without catastrophe and predation. That's entirely possible...but we still do not know if life would advance based on other catalysts over time, or a different energy source.

    That really comes down to a consideration of life, over time in a stable, ample resource filled environment vs. an environment devoid of resources. In the case of life on Earth that caused the need to be able to process sunlight (a mediocre sun at that) which created a miasma for all other life forms which in turn caused a great dying. That miasma then stimulated the need for additional energy sources in which life started to ingest other life.

    We know there are much more significant and exotic stars in the Universe.
    We know there are an unfathomable amount of planets that have the potential for life.
    From the lecture above, and other research, there is a great potential for chemistry to turn into biology based on environment and energy source to create work.

    Put it all together, in combination with the Earth caused catastrophic events for 99% of all life that has ever existed on this planet, and the potential for predatory behavior to be a symptom of this ecosystem and this planet seem all the more plausible...at least to me it does.
     
  16. Hipparchia Registered Senior Member

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    Please provide evidence to explain why you make this claim.
     
  17. Wexler Gadfly Registered Senior Member

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    Just google mutlicellular life...I just did, and what pops up? An article published yesterday...

    http://www.newscientist.com/article...-cell-to-multicellular-life.html#.VYm48flVhBc


    "The leap from single-celled life to multicellular creatures is easier than we ever thought. And it seems there's more than one way it can happen.

    The mutation of a single gene is enough to transform single-celled brewer's yeast into a "snowflake" that evolves as a multicellular organism.

    Similarly, single-celled algae quickly evolve into spherical multicellular organisms when faced with predators that eat single cells.


    These findings back the emerging idea that this leap in complexity isn't the giant evolutionary hurdle it was thought to be."
     
  18. billvon Valued Senior Member

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    And predation likely existed long before that. Many modern bacteria engulf other bacteria to "eat" them. Again, this is the primary theory on how we got our mitochondria around 2 billion years ago.
     
  19. origin Heading towards oblivion Valued Senior Member

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    Out of curiosity, are there scavengers in your idealized planet.
     
  20. billvon Valued Senior Member

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    Right, yes, more energy makes things easier. But what about materials? What happens when all the biologically-available nitrogen is used up? Does life just stop?
     
  21. Wexler Gadfly Registered Senior Member

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    Who is to say that a non-cannibal / non-predatory system doesn't also have other cycles available?

    Remember, part of the issue is the mediocre sun...the biggest stars are more than 100 times as massive as the Sun.

    How the hell do I know?

    We've been over that...but the very article I linked to shows that:

    "Similarly, single-celled algae quickly evolve into spherical multicellular organisms when faced with predators that eat single cells."

    What this shows is that there are TWO types of life forms in that scenario...one that eats and one that gets eaten, but multicellularity occurs...and that is one of the keys to advanced life.

    What is doesn't say is that as soon as the multicellular organism evolved it started eating other living things...quite the contrary actually.
     
  22. AlexG Like nailing Jello to a tree Valued Senior Member

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    The radiation levels from such stars are unlikely to allow for life, and they burn out in just a few million years, not giving life, or even planets, time to form.
     
  23. billvon Valued Senior Member

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    "Cycles" indicate that material is recycled. That can't happen without consuming earlier versions of life. Those earlier versions might be alive or dead; to the consuming organism it doesn't really matter. So if you do have "other cycles" available that will include predation or something very much like it.
    Again, that takes care of energy, not raw materials.
    Right. It most likely happened far before that.
     

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