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Does natural selection apply extra-galactically?

  1. Nov 9, 2005 #1
    Does "natural selection" apply extra-galactically?

    Would the rules of natural selection (in this Universe, but possibly in a different galaxy) still apply?

    In that regard, how might they differ?

    Basically what I'm driving at is, if we were to encounter life outside Earth who popped in extragalactically, would they of necessity be either: seemingly infinitely repressive (and thus able to "force march" the development of tech more quickly) or seemingly infinitely pacific (and thus able to work together to develop tech more quickly)?

    The question is not which one is likely, but if the galactic natural selection would result in either/or possibilities of their nature along these lines.

    If "intelligence" is effectively derived from propogation due in large part to both luck and an developed ability to understand world around us, wouldn't natural selection still apply?

    Forgive me if this is not the correct forum, but I am trying to approach this question from a scientific angle.
     
  2. jcsd
  3. Nov 9, 2005 #2
    If exterrestrial life meets the basic definition of life that we currently use, then natural selection would have to apply.
     
    Last edited by a moderator: Nov 10, 2005
  4. Nov 10, 2005 #3

    turbo

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    Look around you. The world is full of people exhibiting both extremes and every gradation in between. The existence of a Mother Theresa does not forbid the existence an Adolph Hitler or vice versa. Applying the principle of mediocrity, it seems likely that any species that has developed under natural selection will exhibit a range of cooperative behaviors (including willing partnerships, repressive subjugation and everything in between) just like humans do.
     
  5. Nov 10, 2005 #4

    Phobos

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    Here's what you need for Darwinian natural selection...
    1) limited resources (thereby creating competition)
    2) genetic variation
    3) heredity

    So, like franznietzsche said, if its what we know as Life, then the above criteria likely apply anywhere in the universe.

    Interesting thought from Carl Sagan on this matter (and he was talking with respect to human exploration of the galaxy)...
    Given the vast distances in space and probably time (e.g., technological development) between intelligent civilizations, it is likely that, upon meeting of any two, one will be far more advanced than the other. If the more advanced one is also more agressive/cruel, then the peaceful one may not last long (whereas a peaceful, more advanced one could probably defend against any weak attacks).
    Basically, Sagan was saying it's unlikely that civilizations would be evenly matched like we see in Star Trek.
     
  6. Nov 10, 2005 #5

    Garth

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    Perhaps the technology crisis is a filter that rids the universe of the 'advanced' "agressive/cruel" products of natural selection by self destruction?

    So how are we doing?

    Garth
     
  7. Nov 11, 2005 #6

    Chronos

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    The laws of the universe seem to be doing a fine job of limiting our ability to impose our will upon it, or its contents.
     
  8. Nov 19, 2005 #7

    Nereid

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    Homo sap. has been lucky.

    However, I think the 'technology crisis as filter' is in need of a tweak or two ... it won't be vast mega-deaths that would create the crisis (don't we all so love drama! giant tsumanis/hurricanes, earthquakes, asteroid collisions, super-AIDS/flu, ...), more likely it would be failures in social systems (autarky rather than free trade; institutional suppression of innovation, etc) combined with overdrawing on the 'externalities' accounts (water, soil, genetic diversity, etc).

    But, surely a topic for a different part of PF?
     
  9. Nov 19, 2005 #8

    marcus

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    JHE natural selection as we know it operates to adapt organisms to a particular NICHE

    we humans have evolved so that we cope fairly well with THIS EARTH SITUATION, or at least the hunter-gather niche we evolved to fill.

    this does not necessarily mean that we are well-adapted to colonize our galaxy.

    we seem to have SOME of the necessary characteristics---maybe we have all we need, maybe we do not have.

    Our brains and social instincts evolved in hunter-gather tribe life. We may not be able to survive long in techno-civilization and, as a species, we may not be up to the job of colonizing extrasolar planets.

    this is a test. we don't know the outcome
    ========================

    WHAT YOU ASK IS AN INTERESTING ASTRONOMICAL QUESTION, I think. I think what you ask is can one predict (by theory of evolution by natural selection) what might be features of a SUCCESSFUL COLONIZING SPECIES.

    If there was some competition between several species to colonize our galaxy, what characteristics would give a reproductive advantage---improve chance of success.

    I can think of one that is important, that is simply the instinctive DESIRE to spread life. The innate desire not to be confined to one place or planet but to plant the seeds of life in far flung places.
    Any species that succeeds must probably have to PRIORITIZE and allocate resources----so they must want to spread out into uninhabited places. If they dont want to do this strongly enough, then they will consume their resources some other way. So I think this drive must have been bred into them already from the history of their life on their home planet.

    maybe their home planet had many islands, like the polynesian pacific.
    maybe these islands periodically explode. so the species that survives in the long run is the one who always colonizes----it has become second nature.
    =================

    a galaxy like ours has hundreds of billions of planets

    you do not have to imagine EXTRAgalactic travel---everything you area asking about already makes sense if we are just talking about life within this one (Milky Way) galaxy.

    another trait that natural selection might promote is ability to live in cold dry vacuum. If an animal could live in cold dry vacuum it could do very well at colonizing, if it wanted to.
     
  10. Nov 21, 2005 #9

    Chronos

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    Interstellar travel still looks prohibitively expensive to me. By current accounting, it would require all the energy resources on earth to propel a manned spaceship more than a few light years... not a politically appealing prospect.
     
  11. Nov 22, 2005 #10

    Garth

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    My scenario (pure speculation, of course) is that with 1011 suitable stars, and as planetary systems (albeit strange) have not been found to be uncommon, then there are possibly OOM 1011 habitats for life in the galaxy, of which a proportion might harbour life.

    A much smaller number of these might harbour intelligent lifeforms at some stage, these would be examples of convergent evolution with homo sapiens on Earth. By being products of the struggle for survival such lifeforms would be expected to be competative by nature and, once having achieved a stage of technology similar to ours, would also face the 'technology crisis'.

    Perhaps the majority of such lifeforms do succeed in wiping themselves off the face of their respective home planets, however a minority might not and thus survive long-term.

    These are the ones who are most likely to be extant with us and those we are most likely to 'contact', that is if they are willing to risk exposing themselves to such a dangerous species.

    As a speculative exploration of possible SETI contacts is not this subject suitable for this Forum?

    Garth
     
  12. Nov 22, 2005 #11

    Phobos

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    Yeah, the natural selection/social systems discussions could probably better fit in another forum but the space travel/SETI side is generally welcome here. Let's kick it around here for bit more & see how it goes.
     
  13. Nov 28, 2005 #12

    saltydog

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    That's why I've never personally agreed with SETI barring for the moment my admiration for Jil Tarter and Seth Shoshank (sp?) and the passion they both show for their endeavour. Natural Selection does not stop at the stratosphere. And if ETs find our where we are and we have something they want, forget about being nice about it. I say broadcast, "nobody but us amobeas here and we taste really bad".

    That plaque Carl Sagan sent out some time ago may very well come pack to haunt us. He should have known better.

    Natural Selection is a reflection, in my view, of a more profound synergy which I think is universal which I can best explain by a quote:

    "what marvelous adaptive tendencies of diversity in chance-fluctuating environments. Such is a beautiful expression of Quantum Mechanical favor":smile:
     
  14. Nov 29, 2005 #13

    Chronos

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    I strongly feel natural selection is woven into the fabric of the universe. The laws of the universe conspire to force development of more complicated structures over time. The stars themselves [not to mention every other particle and collection of particles in the universe], constructively and destructively interact to explore every possible state of existence available. We have a cute name for that ... entropy.
     
  15. Nov 29, 2005 #14

    Phobos

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    Of course, our radio signals/noise (which have already passed several neighboring stars) will betray our presence long before anything finds those plaques (still within our solar system). At least the plaque is an attempt at a friendly gesture on our part. It's real value might just be in public/poliltical interest in the space program here on Earth.
     
  16. Nov 29, 2005 #15

    Garth

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    What a horrifying thought! - Hitler in 1936 - a la 'Contact', or 'I love Lucy'(!), what do you think 'they' would make of us?

    Garth
     
  17. Nov 29, 2005 #16

    Moonbear

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    Natural selection is not a "force." It also doesn't force development of any new structures. It is the term used to describe that organisms with a variety of traits, when exposed to environmental influences (not some special "natural selection factor" but ordinary things like temperature, water availability, or abundance of prey species), have varied chances of survival. Those that survive best pass their genes on to the next generation, and so forth. Those who do not survive very rarely pass genes on to the next generation. The proportion of individuals exhibiting these traits in a population shifts toward the traits that allow the organism to survive better and away from those that are less advantageous. There is no requirement toward increasing complexity. Sometimes simpler is better.

    With regard to the opening post, sure, assuming any other life forms had heritable traits and variation in those traits, natural selection would be an entirely reasonable assumption to follow from that.

    However, with regard to this statement:
    What does this have to do with natural selection? No, there wouldn't be any "necessity" that any lifeform be either repressive or passive. There isn't even a necessity that they have intelligence. From a natural selection perspective, if there were a hypothetical organism (or a few of them) that did arrive on Earth and was aggressive, they'd probably be outnumbered and killed quickly by humans, which would mean the species wouldn't expand into a new niche, that being Earth. Indeed, whatever selection occurred on their home planet (or whatever celestial body), would be irrelevant to the selection that would occur on Earth, unless the two climates were so incompatible that no organisms on the home planet with traits adequate to survive on Earth ever survived long enough to travel to the Earth.
     
  18. Nov 30, 2005 #17

    saltydog

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    I don't think so Moonbear. Just one could wreak havoc upon the earth simply because to travel such distances would require a technology indistinguishable from magic to us (I'll send Mr. Clark a dollar for using that). We wouldn't have a chance.:yuck: and I don't think they would "come in peace". It's "survival of the fittest" out there as well I believe and the lion doesn't ask the antelope for permission before stomping upon one he thinks he can catch.

    I say we erect a big sign on the north pole you can see from Jupiter that says, "ain't nobody here . . . go away".

    " . . . Mr. Chambers, Mr. Chambers . . . it's . . . it's a cook book!" Remember that one?:smile:
     
    Last edited: Nov 30, 2005
  19. Nov 30, 2005 #18
    1) Do you think every human body has a unique 3billion letters code (DNA) ?

    2) If yes, Do you think there can be a contradiction between the hypothesis of unicity of DNA code and the presence of human bodies in other planetary systems due to relativity ?

    3) If yes, does there exist a communication system that could allow locks of the style : the DNA code n°x cannot be made on earth because it's already present on the planet C out of the galaxy ???

    Rem :
    a) if only earth is settled, one can compute an apprximate duration of humanity : 2^(6*10^9)/(6*10^6)*70 y.: number of possible human beings, 6billions renewed (the cell cannot be freed after death) every approx. 70 years

    b) true twins are made in the woman only...but normally it is through 1 mitosis...in fact one could imagine that the complement to a RNA code is stored into a second spermatozoid, brought to the female egg who did the same operation...so what are those called ?? (there are two different eggs, but RNA code exactly the same) instead of one egg with 1 mitotic separation...
     
    Last edited: Nov 30, 2005
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