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Development of Intelligent Life?

  1. Jan 22, 2009 #1
    Why do some scientists assume that intelligent life may be rare--that because only one high-intelligence--homo-sapiens (us) developed on Earth, that inteligent life is rare to evolve throughout the universe?
    Instead of seeing it that way, why can't you turn that thought around and assume that for every potential life-evolving planet, given sufficient time, there will evolve atleast one high-intelligence (human-level) creature among all of the other different (lower-level) species. that is the way i see it. given each planet(including ours) which goes through a long process of evolving many many different species, there will develop atleast one high intelligence, hyper-conscious being such as ourselves. that makes a bit of sense to me. the fact that we did evolve shows that high-intelligence is indeed possible! arent there any scientists who have this view? or anyone.
     
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  3. Jan 22, 2009 #2

    LURCH

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    Although one can speculate any scenario one desires, we have only one "real world" model on which to base theories. In this will one and only example, only one intelligent race occurred out of the billions of species developed.
     
  4. Jan 22, 2009 #3

    DavidSnider

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    Because there is nothing special about intelligence. Some animals survive by having sharp teeth, some by running fast, we happen to survive by our superior ability to communicate. To us, intelligence is the pinnacle of the evolutionary tree, to an elephant it would probably be their trunk.

    Our intelligence happened to be beneficial in the environment we evolved in. So the question just comes down to what is the probability of a section of space being in a state favorable to intelligent beings?

    It looks very improbable.
     
  5. Jan 22, 2009 #4

    Evo

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    It is suggested that if the dinosaurs had not been wiped out, humans might not have had a chance to evolve. We actually don't know if another potentially intelligent species was wiped out before they could evolve. Lucky for us, whatever we evolved from managed to survive.
     
  6. Jan 22, 2009 #5

    D H

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    I see it the other way around. Every time I play with Drake's equation (a complete hack, IMHO) I get one civilization per galactic cluster at best. Extrapolating from our sample of one (a dangerous thing to do), primitive life may well be somewhat common. Beyond that, I suspect multicellular life is fairly rare, life that can think *at all* is very rare, and "intelligent life" is so extremely rare that each intelligent species is for all practical purposes alone (e.g., one per galactic cluster).
     
  7. Jan 22, 2009 #6
    I would expect that if intelligent life were common we would've heard from it by now or at least detected it in some way. Of course, it is still possible that intelligent life is out there and is ubiquitous, but then you have to explain why they are not communicating with us...

    To paraphrase Fermi and his famous paradox: If they're out there, then where are they?

    Well what if they're not out there? That seems to me to be the simplest explanation that fits our evidence.
     
  8. Jan 22, 2009 #7

    wolram

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    What type of creature (can) attain human like intelligence, i guess it would have to be a creature that had time to think, for example, i can not imagine a humming bird ever reaching human like intelligence.
    http://www.stanford.edu/group/stanfordbirds/text/essays/Metabolism.html

    I can imagine horses, cats , dogs reaching some higher intelligence level, but if they can not use tools they will probable never reach human like intelligence.
     
  9. Jan 22, 2009 #8

    DavidSnider

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    wolram: Your question is phrased oddly. Of course hummingbirds as they are now can't have human intelligence, but that's not to say that it couldn't spawn an evolutionary line that could (You may also be right, that all living birds have no possible pathway to human-like intelligence, but I doubt it has anything to do with 'time to think', and is more a consequence of Dollo's Law).

    From an evolutionary perspective fish 'attained' human intelligence.
     
    Last edited: Jan 22, 2009
  10. Jan 22, 2009 #9
    I wonder which of the posts here are complying with the new rule.
     
  11. Jan 22, 2009 #10

    Evo

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    Of course there were neanderthals that have disappeared. That was a branch that was intelligent, we were more intelligent though.
     
  12. Jan 22, 2009 #11

    DavidSnider

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    His link says nothing about the ability of birds to evolve human-like intelligence...

    What would you have me do to be compliant with the new rule? Post a paper showing we evolved from fish? A link to Dollo's law? Amazon.com link to Climbing Mount Improbable by Richard Dawkins?
     
    Last edited: Jan 22, 2009
  13. Jan 22, 2009 #12

    wolram

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    I used the humming bird as an example because it has a very high metabolism, it has to spend all it's time feeding or at rest, this suggests to me a dead end of its evolution,
    it would simply die if it took time off for experiment.

    A dolphin may have the ineligence to imagine making a tool, but it could not mine the ore
    or smelt it or work it, another dead end.

    In other words a creature would have to evolve to a human like form, or be able to use tools as well as as having human like inteligence.
     
  14. Jan 22, 2009 #13

    DavidSnider

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    'Take time off for an experiment?' Evolution is not driven by the organism itself. It's not like if hummingbirds could take some time to work out puzzles their brains would get better in future generations. An organism can't control which genes mutate or what selective pressures are put on it.
     
  15. Jan 22, 2009 #14

    D H

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    There is no way to prove life doesn't exist elsewhere. Our ability to detect life has very limited range, and even then we may be overlooking what will be in retrospect obvious signs. Discussion of alien life will remain overly speculative for at least a while. Discussion of alien intelligent life will remain overly speculative for a lot longer (unless Joe Alien lands on the White House lawn or calls us).

    The discussion of alien life is pertinent to science (and even gets some scientific funding). The concept has been discussed in several prestigious technical magazines. So long as everyone involved agrees that discussion of alien life, intelligent or not, is purely speculative, this might well be one place where the more strict rules do not quite apply.
     
  16. Jan 22, 2009 #15
    If science is about applying the scientific method to any conceptual thought, eventually testing it against reality, then alien life cannot be tested. Also if science is about Popperian falsifiability then the concept of alien life cannot be falsified.

    Hence, alien talk is not science. And if the standards are that rigourous then this thread should not exist here.
     
  17. Jan 22, 2009 #16

    D H

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    So move this thread to General Discussions, particularly since it focuses on alien intelligence.

    Discussion of alien life can be scientific. We can talk about what to look for a signatures of life, what life would look like in other star systems (i.e., how to falsify the hypothesis that the Earth is unique). For example, http://www.sciam.com/article.cfm?id=the-color-of-plants-on-other-worlds.
     
  18. Jan 22, 2009 #17

    nrqed

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    I personally think that this is a narrow-minded view of science. I think that many great scientific thinkers did not tell themselves "I must first think of a way to cnfirm or to falsify my ideas before I devote more time hinking about them".

    I don't think that Darwin thought that he should not pubish his ideas until they could be proven or falsified. The concept of hidden variables in quantum physics was thought to be unfalsifiable for a very long time...it did not stop Einstein and his colleagues from bringing up the question and even publishing about it.
     
  19. Jan 22, 2009 #18

    Evo

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    Discussing "intelligent life" and evolution, IMO, is an interesting discussion. No one has actually made any specific scientific claims that require verification, so the thread doesn't violate the rules. I may move the thread to biology, if Monique agrees.

    Do not forget there is a serious field of astrobiology now.

    Astrobiology - Life in the Universe

    http://astrobiology.nasa.gov/
     
  20. Jan 22, 2009 #19

    Xnn

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    As far as I know, the current liberal estimate from the Drake eqation is less than 3 advanced civilizations in our Galaxy. That is out of about 300 Billion stars spread over an area 100,000 light years in diameter! So, it is highly unlikely that there is another advanced civilization within 1000 light years of earth.

    The next problem is the strength of possible ET radio transmissions and our ability to detect them. For example, while humans generate radio transmissions, almost none are focused outside our planet. It's not that we don't have the technology for transmitting the signals, it is the cost. Who wants to spend millions of dollars on the electric bill to send signals into outer space to ET? And while we do have sensitive equipment for receiving radio transmissions, they aren't powerful enough to receive non-focused transmissions from more than a few light years away. But they are even further away from us.

    So, even if ET were only 100 light years away, it is unlikely they would be spending the resources to transmit anything towards us that we could detect. In addition, even the most liberal application of the Drake equation shows that it is unlikely that ET is within 1000 light years.

    The universe is another story. With a 100 Billion Galaxies in the observable Universe, there are likely to be more than that number of intelligent civilizations.
     
    Last edited: Jan 22, 2009
  21. Jan 23, 2009 #20
    Whilst it may still not be science but the Drake equation is flawed, one element is missing, planet stability. Whenever the precession cycle and the obliquity cycle are about equal in period, resonance would occur and the planet could enter a chaotic zone with extreme obliquity cycles. It is hypothezed that Venus' end state is the result of entering such a chaotic zone and without the big moon the Earth precession cycle would have been much slower and could have been in resonance with the obliquity cycle at certain conditions.

    It's obvious that chaotic obliquities lead to extreme climate swings and perhaps other effects (tides?) that may impair 'intelligent' life forming.

    Therefore it appears that we need the moon to stabilize the Earth rotation for stable climates, and how big is the chance that a Drake approved planet also is stabilized against cycle resonance?
     
    Last edited: Jan 23, 2009
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