Evolution :)

Discussion in 'Politics, Religion, Social Issues' started by AP_piano295, May 16, 2009.

  1. macrumors 65816

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    #1
    So I have a habit of wandering through wikipedia starting with one thing I've always wondered about and then just following the path of articles/ideas for an hour or two.

    Tonight I started with velvet ant, then moved to fire ant and found the Phoridae species of fly (http://en.wikipedia.org/wiki/Phoridae) and the article stirred a question I frequently have about evolution. Basically how the hell did that happen??

    The reason I didnt put this in the political form is because I'm not saying I dont believe in it (I do) I'm just interested to know how an organism like this would develope (an evolutionary sicentists about?)

    I just dont understand how this could happen (even if life has been around for the past 4 billion years)

    How would a fly develop-->

    The behavior of laying larve in ants
    How would the larvae know to eat the ants brain
    Why would the larvae have an enzyme used to drop off an ants head
    And how would it know to use it.

    How the hell did this thing evolve??
     
  2. macrumors 65816

    jackiecanev2

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    #2
    Wirelessly posted (BB 8900: Mozilla/5.0 (iPhone; U; CPU iPhone OS 2_2_1 like Mac OS X; en-us) AppleWebKit/525.18.1 (KHTML, like Gecko) Version/3.1.1 Mobile/5H11 Safari/525.20)

    People look at evolution and think it must be intentional: for example, we developed opposable thumbs because they are useful. There is no end-goal in evolution when it comes to acquiring traits. Evolution is predicated upon the random, and which random mutations and genetic alterations are this selected over other existing traits over an extended period of time.



    Basically, every evolutionary trait is chance, a random accident, that just happens to make us more fit and this reproduce more than our peers. Over millions of years, of course.
     
  3. macrumors 603

    mobilehaathi

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    #3
    Evolution happens over such unfathomable stretches of time that humans have quite a difficult time imagining along the near continuum of changes necessary for a substantial divergence between species.
     
  4. thread starter macrumors 65816

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    #4
    and were in the political forms :rolleyes:
     
  5. Moderator emeritus

    EricNau

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    #5
    This would provide an advantage, no? Therefore, the flies that exhibited such behavior (by chance) thrived, while those who laid their larva elsewhere died out.

    This is an instinctual trait. Those flies that didn't have this instinct died, leaving only those with the trait to survive and reproduce.

    Again, a combination of an evolutionary benefit and an instinctual behavior, both obtained through natural selection.

    The same way everything else did. ;)
     
  6. thread starter macrumors 65816

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    #6
    But what mutation in an organisms code would ever make it start laying eggs on ants is more what I'm getting at.

    I would undertand if this was a thinking animal (dolphin, dog, monkey, person) but a fly...what could cause a fly to behave in this way. What would make its ancestors behave in this way?
     
  7. macrumors P6

    iJohnHenry

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    #7
    Trial and error, over many, many, millennium.
     
  8. macrumors 603

    mobilehaathi

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    #8
    Think about a confluence of heritable changes that modified the behavior of the fly such that some quality about the ants made it the preferred environment to lay eggs.

    No one can actually answer this for you, but I think you're trying to reason too directly about the whole thing. This likely didn't just happen at the flip of a switch, but rather a gradual change in behavior over the course of a very very long time.
     
  9. macrumors 68030

    .Andy

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    #9
    Or did you just see it on Digg today? http://digg.com/general_sciences/Brain_Controlling_Flies_to_Triumph_Over_Alien_Ants

    Flies of many genuses lay their eggs in animals. Deceased or otherwise. It's not that novel a concept. Laying eggs in a bountiful food supply makes perfect sense.

    It doesn't "know" to eat the brain. The brain has the right chemical composition that matches chemoreceptors on the larvae. The larvae then have a decent meal. Much as every species is attracted to food.

    Again it doesn't "know" how to use it. it just uses it. For instance the enzyme could have originally been used to digest connective tissues and as a bonus the larvae that expressed more of it/a specific isotype gained a survival advantage.

    As per EricNau.
     
  10. macrumors 68020

    Gelfin

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    #10
    From this end, looking back, it looks like something an organism would have "decided" to do, but there were never any decisions at all. You see flies engaging in seemingly inexplicably complex behavior. What you don't see is the countless majority of flies over a very long period of time who didn't behave that way, and whose descendants are not here to tell us about it as a result.

    Hypothetically:

    Flies that laid their eggs in dead carcasses instead of live hosts were outcompeted by numerous other insect species with the same strategy. They died out.

    Flies that laid their eggs in hosts that succumbed too easily and died too quickly became similarly vulnerable to other species with their own designs on the carcass. They died out.

    Flies that laid their eggs in hosts with immune systems capable of attacking the larvae effectively never stood a chance. They died out.

    Flies that laid their eggs in ants, but left the ant to behave normally, found their larvae survived, but when they emerged they were surrounded by hostile ants who slaughtered them. They died out.

    Flies whose larvae modified ant behavior in more generalized ways ended up causing the ants to die in locations away from other ants, but otherwise unsuitable for the larvae to survive upon emerging. They died out.

    But at each step of the way, a few flies didn't get it wrong. They laid their eggs on living hosts, reducing competition, so more of those larvae survived to maturity. Over several successive generations, that random behavior became a heritable tendency, because while random success can get you through one generation, only reproducible success can lead to consistent survival.

    A few of those flies laid their eggs on ants, and the ants happened to survive just the right amount of time to allow consistent survival. A few of those addled the ant's brain, causing it to leave the colony, resulting in more consistent survival. A few caused the ant's addled brain to crave moist, dark places. Each time, the flies that are able to consistently produce the more optimum result are more likely to reproduce, and thus more likely to produce flies that exhibit the behaviors that produce the optimum result.

    In this way, what appear to be highly complex solutions to the problem of survival emerge, but nobody had to sit down and plot out the details. They emerge because "nature" produces a hell of a lot of flies over an unimaginable amount of time, and then tries really hard to kill them. You only see who's left standing.
     
  11. macrumors 68030

    Iscariot

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    #11
    Simpsons did it!
     
  12. macrumors P6

    iJohnHenry

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    #12
    Why do I have 4 inch long hairs on my forearm??

    Is this some kind of DEW line, for Bear-sized insects? :eek:

    Discuss.
     
  13. macrumors 6502

    stevento

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    #13
    It's called genetic traits. Don't like it? Try nair.
     
  14. macrumors 68000

    NoSmokingBandit

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    #14
    Much like evolutions say creationists are silly for returning to the "god did it" mantra, evolutionists end up with the old adage about monkeys and Shakespeare. Add an infinite amount of time to any equation and evolutionists claim that anything can happen. Which somehow equates to scientific proof....
     
  15. macrumors 604

    zap2

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    #15
    :rolleyes:
    Yes, thats the only proof for evolution
     
  16. macrumors 68030

    .Andy

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    #16
    What exactly is wrong with this?
     
  17. macrumors 68020

    Gelfin

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    #17
    First, there is no such thing as an "evolutionist."

    Second, not exactly. Not unless every few years you rounded up the literary output of all the monkeys and compared it to Shakespeare, then killed off the half whose output was least like Shakespeare, encouraged the remainder to breed and put the new monkeys to work at the typewriters recently vacated.

    You'd most likely produce an actual monkey Shakespeare who understood what he was writing much faster than it would take for random typing from undifferentiated modern monkeys to accidentally turn out Hamlet.

    This is the critical point that evolution deniers miss when they start harping on randomness. Selection is not random. It is a sieve. What comes through is refined towards a particular outcome.
     
  18. macrumors 6502

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    #18
    Actually, most of the answers here have been pretty clear that we don't know exactly how this thing evolved, and thus it isn't proof of anything. There have been some reasonable fables proposed that fit the pattern both of this fly and of other organisms where we have been able to observe the process, but in the end they are untestable hypotheses.

    You have the process backwards. We don't look at an organism, come up with a complex yet beautiful story about how it evolved, and call that proof. That is how religion operates. Instead, we come up with a hypothesis and design an experiment to indeed prove that some pattern is caused by some process. It's been done enough with evolution that when we look at some pattern, such as the behaviors of the Phorid fly, we can come up with a beautiful and complex story to explain it's evolution even knowing that it can't ever be tested. We still know that somehow, it did evolve. It's the beauty of having tested, proven, well-established and general theories. You don't have to prove it in every case.
     
  19. macrumors 65816

    designgeek

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    #19
    It's tough to work out in your head since it took so long. It's completely random, and it's weird to think that we evolved from bacteria over billions of years. Anything that's different was a mutation in the genome many many years ago and for any number of reasons that individual with the mutation was able to survive more easily or what ever and thus we have people. Sharks for example have not had a valuable mutation in millions of years, and that's why they have changed so little. In their case, a mutation has not turned out to be an advantage. I like to try to figure out how any given trait was possibly passed down or where we as a species is going on an evolutionary level. Who knows what we'll be able to do in a few million years.
     
  20. macrumors 68030

    .Andy

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    #20
    I generally agree with the rest of you post designgeek but it's best to clarify that evolution isn't completely random. It's the non-random selection that makes it so powerful. Which is why I consider the monkey/shakespeare analogy above to be somewhat fitting.....
     
  21. macrumors 6502

    PcBgone

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    #21
    Enlighten me. What Proof do you have of evolution? and I presume you have proof of macroevolution?

    Here, I thought Evolution was only a THEORY. And that before it could be a law, that it had to be proven. Do tell. Im very interested...
     
  22. macrumors G3

    NT1440

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    #22
    A semantics game?? In PRSI!? :p


    I really hope that through better education (such as disallowing for creationism to be taught in schools) people will actually be able to understand what the term evolution means. In fact, I wish that could happen with alot of the current buzzwords (communism, socialism, mcarythism, etc)......
     
  23. macrumors G4

    Chundles

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    #23
    Erm, you do know what a theory means in the scientific context? It's not The Hypothesis of Evolution...
     
  24. macrumors 65816

    XnavxeMiyyep

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    #24
    The same could be said about gravity. No one knows the exact mechanisms that cause objects with mass to attract one another, and it is still a theory as opposed to a law.

    Theory in science does not mean what you seem to think it means, which I'm guessing is more akin to a hypothesis.

    Evidence for "macroevolution" can be found in the existence of "microevolution" and the fossil record.
     
  25. macrumors 6502

    PcBgone

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    #25
    Theories are basically educated guesses. They take the accumulated data and make a guess as to what happened. This can change as data changes.

    Laws have been proven. Newtons Law of Gravity for one. It can be recreated.

    Evolution is not a law. We dont call it the Evolution Law. It is still labeled a Theory. An Educated guess.

    Zap claimed he had proof of evolution. Proof would make it a law, as it could be recreated. Im awaiting said proof. If he can provide it I will renounce my Christianity. If not, then I will continue to believe that Evolutionist have just as much Faith in evolution, as Creationist have in God.
     

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