Received: by alpheratz.cpm.aca.mmu.ac.uk id CAA06706 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-bounces@mmu.ac.uk); Mon, 27 Aug 2001 02:41:12 +0100 From: <joedees@bellsouth.net> To: memetics@mmu.ac.uk Date: Sun, 26 Aug 2001 20:45:23 -0500 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Re: Coordinated behavior among birds, fish, and insects Message-ID: <3B895FE3.19841.2CF5AA@localhost> In-reply-to: <002301c12e66$52d64300$6f24f4d8@teddace> X-mailer: Pegasus Mail for Win32 (v3.12c) Sender: fmb-bounces@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
On 26 Aug 2001, at 12:35, Dace wrote:
> From: "Vincent Campbell"
>
> > <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).>
> > >
> > Birds capacity to see behind them, given the position of their eyes
> > of the side of their head (apart from birds of prey who have more
> > front facing eyes and- notably- don't flock), is actually very good.
> > They have
> a
> > blind spot immediately behind their tail, but birds do not fly in
> > straight lines (I believe that's something to do with the
> > aerodynamic effects of birds flying), but in positions slightly to
> > left or right of the bird in front of them (the famous Geese flying
> > V is the obvious example). That gives them ample visual room to see
> > what the birds behind them are doing.
>
> Point taken. But does this also apply to fish in a school, which
> demonstrate the same apparently collective behavior? Can this account
> for the fact that birds are able to react to changes in flock
> direction faster than their measured reaction time? Can it account
> for their ability to move exactly in the right way when the shift
> comes?
>
Yes, it does; the overwhelming majority of schooling fish have side-
set eyes, just as birds do. And the most likely hardwired
algorithmic 'autopilot' reaction time of birds in a flock, their natural
habitat, as was pointed out before, would most certainly be faster
than their in-a-foreigh-evvironmen and individual (thus more
processed and mediated) laboratory reaction time. And the
algorithm evolved to be the most effective solution to the problem of
danger to a flock, so it's right a lot of the time, but it's not right ALL
of the time - otherwise predatory birds such as hawks, falcons, and
other raptors, who predominately hunt within flocks of prey, would
have long ago starved to extinction.
>
> > <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.>
> > >
> > Of course they do mathematics. All organisms do- just not in the
> > conscious sense that we can with a piece of paper. Mathematical
> > calculations are being done by our brains all the time we're alive-
> > certainly when we're moving. All the time we're typing our e-mail
> messages
> > the brain is engaged in mathematical calaculations in relation to
> > our hand movements. Birds do it too when flying, landing
> > hopping/running etc. etc. So do other animals. That's not to say
> > that organisms aren't subject to forces, like gravity, but you just
> > don't another new force to explain organisms movement.
>
> Math is a language which describes reality more accurately than
> previous languages. Like them, it exists strictly within human
> imagination. The brain facilitates our mathematical abstractions, but
> it doesn't contain them. Abstraction is not a property of material
> objects. Even calculators don't do math. "Calculation" is merely our
> interpretation of the purely physical activities that occur in the
> machine.
>
Flocking birds and schooling fish, among other species possess
evolved and hardwired algorithms, which respond to particular
circumscribed stimuli in paradigmatic and automatic ways; it's also
known as instinct.
>
> > Loathed as I am to give to some help with this theory, but perhaps a
> > better example than a flock of birds in flight for your arguments,
> > might
> be
> > a slime mold particularly when all those cells seem to conglomerate
> > and
> move
> > like a much larger single organism. Does Sheldrake have any views
> > on
> slime
> > molds?
>
> Thanks for the suggestion.
>
> Ted
>
>
>
> ===============================================================
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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: http://www.cpm.mmu.ac.uk/jom-emit
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