Re: Direction in evolution, from Re: Are there things that don't evolve?

Interesting. I never thought of the IC argument as a teleological one. I
wonder if "purpose" needs to be defined here. The flagellum and blood
clotting mechanisms certainly have "purpose": to move a bacterium around in
order to avoid predators and find food; and to prevent an animal with a
circulatory system from bleeding to death.

In an evolutionary scenario, that those purposes are or have been useful to
the survival of the organism is evidenced by the fact that the flagellum and
blood clotting mechanisms have in fact developed and are ubiquitous in a
wide variety of organisms. In a similar vein, lots of people use
old-fashioned wood and spring mousetraps because they work efficiently.
Since no one has built a better mousetrap (at least not a practical,
affordable one), the basic design survives.

It's a different question to ask whether the function a mechanism performs
was planned by an intelligence. I think that's what you mean by "purpose."
But the IC argument as I understand it doesn't claim "purpose / function" =
"purpose / planned teleology". Rather, it's an argument against the
feasibility of gradually assembling the mechanism. The IC mechanism is
useless if any of its parts are removed. You can't reasonably or reliably
catch mice with a spring, or lever, or base alone; all the parts need to be
completely assembled before it works. Therefore, the mousetrap can't be
developed in small stages. It must be planned complete from the outset.
That kind of planning suggests intelligence.

A principal argument against IC in biology, as I understand it, is that the
analogues of the spring, lever or base, or precursors of those components,
could have served other useful functions and over time could have been
adapted to serve different or related functions when assembled as a system.
Thus Ken Miller in his rebuttals to Behe cites a group of papers showing
various other functions of the protiens or precursors of the protiens that
comprise the bacterial flagellum and proposes that, though the exact pathway
may not yet be known, the flagellum could have developed over time by
adapting those protiens and adding other components.

We're left then with the age-old divide: one the one hand, evolutionary
biologists say that given enough time, a naturalistic developmental pathway
is plausible, even if the precise pathway and mechanism aren't yet known;
and someone questioning evolutionary biology says the complexity of the
system and the amount of time required in comparison to the time available
leaves an insurmountable gap that only reference to God (a designer) can
fill.

On 4/4/06, Brent Foster <bdffoster@charter.net> wrote:
>
> My origional point in this was that Irreducible Complexity (IC) assumes
> purpose and therefore is circular reasoning. The question at issue in ID is
> whether complex biological structures like the eye, flegellum etc. evolved
> through natural processes or are the result of intelligent design. In
> support of the assertion of design, the irreducible complexity (IC) argument
> has been used. The mousetrap has been offered as an example of IC. Because
> it will not function if one of it's parts is removed, intermediate stages
> will not be funcional and therefore offer no selective advantage. But this
> assumes that the mousetrap HAS a purpose: catching mice. The evolutionist's
> contention is that what appears to be purpose is actually adaptation and is
> produced by natural process. Ultimate metaphysical purpose is beyond the
> scope of science. But when a complex biological structure performs a task
> that it seems very well suited to, it is the very question at issue whether
> this is adaptation on the one hand, or design for a purpose on the other. So
> to assume purpose is circular reasoning. It may be that the specific
> examples given in the past that were allegedly examples of IC (eye,
> flagellum, blood clotting etc.) don't hold up to scrutiny. But I think the
> IC argument in general is weak because of the assumption of purpose.
>
> Brent
>
>
> ---- "Alexanian wrote:
>
> =============
>
> From Wikipedia, the free encyclopedia
> This apocryphal story relates to Isaac Newton's supposed belief in design.
> Isaac Newton engaged in frequent discussions on the subject of God and
> design with friends. One atheistic friend disputed the evidence of design in
> reality.
> The story goes that Sir Isaac then built a clockwork model of the Solar
> System, including all the planets and moons that were known at the time. The
> moons revolved around the planets and they all in turn revolved around the
> Sun, while each individual orb turned on its axis. "How were you able to
> construct such an ingenious device?" asked the friend when he saw it. "I
> just tossed the pieces at random into a corner, and they accidentally
> assembled themselves into this model," Newton replied. "That's absurdly
> impossible," protested the other. "A lot less absurd," countered Sir Isaac,
> "than your belief that such was the origin of the real Solar System, of
> which this toy is but a much simplified model."
> Though widely cited today, there is little evidence to show the incident
> ever happened.
> Retrieved from "
> http://en.wikipedia.org/wiki/The_Parable_of_the_Solar_System_Model"
>
>
>
>
>
> From: Gregory Arago
> Sent: Tue 4/4/2006 5:27 PM
> To: David Opderbeck; Bill Hamilton
> Cc: Brent Foster; asa@calvin.edu
> Subject: Re: Direction in evolution, from Re: Are there things that don't
> evolve?
>
>
> The mousetrap analogy is just that, an analogy. It isn't 'real' science
> and fails (against the ID case) to distinguish between human-made and
> non-human-made things. Likewise, only for this reason does Dr. Behe continue
> to re-speak using his Mt. Rushmore example.
>
> Mouse traps are 'designed,' 'concocted,' 'engineered,' 'constructed,'
> 'created,' 'built,' 'fabricated,' 'made' or what have you...by persons.
> Biological things, however, are not. (Let's leave the bio-tech issue aside
> for the moment.)
>
> Yes, I think Bill is "stretching things by saying this is evolution."
> There have been 'changes' in animal traps and there are certainly 'trial and
> error' methods employed across the map (even in humanitarian sciences). But
> calling this example 'evolution,' which continually invokes 'random
> mutation' (I see little randomness or mutation in trying to catch an animal
> to eat) or 'natural selection' (this is clearly an example of 'human
> selection,' if we are not to reduce human beings to merely 'naturalistic
> determinism') is fallacious. Granted that evolutionary theory is more than
> it's two most celebrated 'mechanisms' - but please we shouldn't dodge them -
> then at least biological evolution and (computer) engineering evolution
> should be properly distinguished.
>
> This (almost) mantra - "Write a simple program and evolve it" - is quite
> an astonishing thing to me. People choosing to 'evolve' programs?
>
> Regards,
>
> G. Arago
>
>
> p.s. just (within the last few minutes) had someone try to convince me
> Amway 'has a great system of making money' - do people 'evolve' into being
> Amway millionaires?
>
>
> David Opderbeck wrote:
> Without getting into a heated debated about the mousetrap analogy -- Bill,
> I don't think this answers it, since you're assuming an intelligence that
> arranges the parts of the trap to work a certain way. I don't think the
> mousetrap analogy is designed to argue that engineered designs never
> progress through stages of engineering.
>
>
> On 4/3/06, Bill Hamilton wrote:
> The mousetrap isn't even a good example of something that could not have
> evolved. Imagine a cave man who comes on an animal which has been killed by
> a falling tree. After enjoying a good meal, he realizes that he can arrange
> a log to fall on an animal, so he rigs a log with a vine rope and he stands
> ready to pull the rope, causing the log to fall on an animal walking under
> the log. Eventually he (or someone else) realizes he can use bait to cause
> the animal -- in the process of trying to get the bait -- to trip the dead
> fall. Fast forward a few thousand years and you get a bunch of derived
> devices: bear traps, mouse traps, etc. Am I stretching things by saying this
> is evolution? Maybe, but the trap has moved from a primitive dead fall to a
> spring-loaded modern trap by a number of stages, by trial and error. And all
> the intermediate stages, though they are missing some of the features of the
> modern trap, are functional.
>
>
> Have a question? Yahoo! Canada Answers. Go to Yahoo! Canada Answers
>
>
Received on Wed Apr 5 09:31:08 2006