Re: Coordinated behavior among birds, fish, and insects

Date: Fri Aug 24 2001 - 03:05:52 BST

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    Subject: Re: Coordinated behavior among birds, fish, and insects
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    On 23 Aug 2001, at 11:20, Dace wrote:

    > > <The naturalist Edmund Selous has studied flocking behavior in
    > > dunlins. He
    > > > found that one or two birds located somewhere in the flock would
    > initiate
    > > > a
    > > > change in direction, and this change would then radiate through
    > > > the
    > flock.
    > > > He tested their reaction time in a laboratory and found it to be
    > > > at 38 milliseconds. But the change in direction of a flock
    > > > radiates from bird to bird at 15 milliseconds, more than twice as
    > > > fast as their reaction time. Also, the 38 millisecond reaction is
    > > > always arbitrary, unlike the precisely coordinated behavior of the
    > > > flock.>
    > > >
    > > Reference please.
    > Selous, E., *Thought Transference, or What? in Birds*, Constable,
    > 1931.
    > Potts, Wayne K., "The chorus line hypothesis of manoeuvre
    > co-ordination in avian flocks," Nature, 309:344-345, 1984.
    > It was Potts, not Selous, who measured the reaction time in dunlins.
    > Potts compared flocking behavior to a chorus line. While the reaction
    > time of humans is 194 milliseconds, the gap between kicks in a chorus
    > line is only 107 milliseconds. Potts said the people in the chorus
    > line are able to predict when their turn will arrive, because they see
    > it coming out of the corner of their eye. He claimed this effect
    > applied to birds in a flock as well. The problem is that, half the
    > time, the wave approaches each bird from behind, implying that they
    > have 360 degree vision. And even if the birds could see the wave
    > coming, this doesn't explain how they're able to move so precisely
    > with it. Despite being densely packed together, the birds never bump
    > into each other. You may balk at my use of that dangerous work,
    > "never," but birds in a flock have *never* been observed to collide
    > (at least not by anyone who was taking notes).
    Has this dude ever looked at the eye spacings of birds? Unlike us
    humans, saddled with two frontal orbs and a <180 degree lateral
    visual span (which does have the advantage of permitting us
    stereoscopic vision and resultant depth perception), birds have their
    eyes on (opposite) sides of their heads, and possess a > 300
    degree visual panorama, with not much visual overlap.
    > > Differences in measured reaction time is not a
    > > problem for the basic point that birds that flock are capable of
    > > applying simple mathematical rules in order to prevent the birds
    > > bumping into each other. I don't know how reaction time were
    > > tested, but we know, for example, that motor racing drivers have
    > > faster than average reaction times than ordinary drivers. Is it not
    > > possible that a bird's reaction times in flight are faster when in a
    > > flock than when flying alone, and that the direction of movement is
    > > relatively arbitary when flying solo, and not
    > when
    > > in a flock.
    > As I said, birds don't do math, any more than planets do. But that
    > doesn't mean they're not subject to field-based forces, such as
    > gravitational or morphic, which are themselves describable
    > mathematically.
    It doesn't mean that they are either, just as it doesn't mean that
    there are dwarfs fellating centaurs beneath the mountains of the
    moon just because we have not burrowed there to detect their
    absence. The nonexistence of the invisible absent is difficult to
    detect, and ad ignorantium fallacies based upon such
    considerations fuels many phantasmagoric fantasies.
    > > <This group-mind effect is revealed in the arch-building behavior of
    > > > termites. Researchers commonly observe termites building columns,
    > > > and
    > if
    > > > one column is close enough to another, then the termites, at a
    > > > certain height, will begin building the columns together into an
    > > > arch. Though
    > the
    > > > termites are blind, and none of them are running back and forth
    > > > between the columns to measure the difference in their locations,
    > > > the two columns always meet up perfectly. It was assumed that the
    > > > termites use their sense of smell to guide the columns together,
    > > > but when Eugene Marais stuck a
    > steel
    > > > plate between two columns, he found that they still matched
    > > > perfectly. Marais also discovered that all the coordinated
    > > > activities of the
    > termites
    > > > are somehow facilitated by their queen. Even if the queen is
    > > > isolated from the workers in a compartment, when the queen is
    > > > killed, all work
    > instantly
    > > > stops.>
    > > >
    > > Wouldn't all social insects disperse on the death of the central
    > > queen?
    > They lose their social behavior instantaneously, before the message
    > has had a chance to be transmitted chemically.
    I doubt sincerely if a fellow working in 1937 before pheromones
    were even isolated could have proven same.
    > > <Sheldrake has never suggested that traffic jams are caused by
    > > morphic fields
    > > > (though morphic resonance with past drivers might cause a
    > > > progressive improvement in our ability to drive safely).>
    > > >
    > > Might or should? Either this theory applies universally or not at
    > > all, it can't apply to just those things you want it to.
    > No one's experimentally demonstrated morphic resonance in the case of
    > driving. But you're right to point out that if it's true in general
    > it would have to apply to driving cars.
    And queues at theatre ticket lines, where actually, something aptly
    named queueing theory applies.
    > > Apologies for the intensity of this discussion, it's not personal on
    > > my behalf, I'm just enjoying the intellectual fencing.
    > No prob.
    I love exterminating ideological infestations.
    > > I have a feeling that the problems of MR are related to the problems
    > > of memetics, that some have suggested, namely- why have the theory
    > > at all? What does it add that isn't covered by other well
    > > established, and empirically supported theories? Etc. This
    > > discussion is a good work-out
    > for
    > > those kinds of arguments.
    > > Vincent
    > Memes make a lot more sense in the morphic model rather than the
    > materialistic model. As Kenneth pointed out, they share the same
    > basic idea, that a given unit of form picks up momentum as more people
    > adopt it. Without the principle of like-affects-like, it's hard to
    > explain how certain memes "catch on." Ultimately, memetics will sink
    > or swim with morphics.
    I seriously and sincerely doubt this; the differences between
    memes and genes are 1) communication: genes - sexual
    reproduction, memes - communication; 2) mutations: genes -
    random, memes - both random and intentional; 3) selection: genes:
    natural (unintentional), memes - both intentional and inadvertent.
    However, they share the evolutionary paradigm of mutation,
    replication, selection. The morphic-memetic sink-or-swim-together
    claim just ain't a straw you can grasp.
    > Ted
    > ===============================================================
    > This was distributed via the memetics list associated with the
    > Journal of Memetics - Evolutionary Models of Information Transmission
    > For information about the journal and the list (e.g. unsubscribing)
    > see:

    This was distributed via the memetics list associated with the
    Journal of Memetics - Evolutionary Models of Information Transmission
    For information about the journal and the list (e.g. unsubscribing)

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