On Fri, 10 Jan 1997 13:43:05 -0500, Brian D. Harper wrote:
>SJ>In any event, Denton *one the very same page* makes it clear
>what he means by "pure chance", and it is the same meaning as
>Dawkins gives it, namely "blind to the adaptive needs and
>requirements of the organism":
BH>In any event, Brian Harper *in the very same thread* also made
>this clear. Good grief :-(.
Agreed, This was after my post. But in any event, what was the
Brian's original point then?
[...]
>BH>Richard Dawkins, in his new book <Climbing Mount Improbable>,
>goes to great pains to distance himself from such a notion as this.
[...]
SJ>Indeed he does, but he admits it is due to *Darwinists* own
>over-emphasis:
BH>I see. So this is what Dawkins meant by "...a feeble basis to the
>distortion." ?
Dawkins *claims* it is a only "a rumour, a feeble basis to the
distortion". But then he goes on to confirm it was not either, but
was in fact what Darwinists themselves say:
"But Darwinians make the fuss that they do about the 'randomness' of
mutation only in order to contrast it to the non-randomness of
selection, the other side of the process." (Dawkins R., "Climbing
Mount Improbable", 1996, pp70-71)
[...]
>BH>Darwinism involves random mutations + natural selection.
>Natural selection is about as opposite from pure chance as one
>could get.
>SJ>Agreed. But it is the *combination* of "random mutations" with
>"natural selection" that makes the *whole* process essentially
>random:
BH>Let's turn this around and see what we get:
>
>Agreed. But it is the *combination* of "natural selection"
>with "random mutations" that makes the *whole* process
>essentially non-random:
No. It's still the same thing - essentially random. Even Dawkins
admits that selection can go only so far and must wait for more
random mutations:
"If anything, selective breeders experience difficulty after a
number of generations of successful selective breeding. This is
because after some generations of selective breeding the available
genetic variation runs out, and we have to wait for new mutations.
It is conceivable that coelacanths stopped evolving because they
stopped mutating - perhaps because they were protected from cosmic
rays at the bottom of the sea..." (Dawkins R., "The Blind
Watchmaker", Penguin: London, 1991, p247)
Even natural selection is not all that non-random. Neo-Darwinists
doubt that natural selection would produce human-like intelligence
again:
"PD: The picture which Richard is giving us is that it's much more
of a lottery, much more of a blind groping about. The question that
we have to ask is if the earth was hit by an asteroid tomorrow and
everything but simple microbes were destroyed and we came back in
another 3 or 4 billion years, would we expect to find homo sapiens
here aga in. Well, of course not.
RD: Of course we wouldn't!
PD: No, of course not. But the question is would we expect to find any
intelligent life and I think most biologists would say no.
McK: Richard Dawkins, I know you're bursting to say something there.
RD: Yes. It is not in my view sensible to invoke fundamental laws of
physical improvement for the biological improvement of complexity or
running speed or anything else. If you wiped our life and started
again- no, you would not get homo sapiens. I tell you what you
would get, you would probably get a great diversity of living form .
You'd probably get plants, animals, you'd probably get parasites,
you'd probably get predators, you'd probably get large predators,
small predators. You might well get flight, you might well get
sight. There are all sortss of things that you can guess that you
might get. You would certainly not get a re-run of what we've got.
(McKew M., interview with Dawkins R. & Davies P., "Lateline", 19
June 1996, in "The Origin of the Universe", Australian Rationalist, No.
41, Spring 1996, pp72-73)
[...]
>SJ>It is essential for Dawkins to maintain that "mutation is random
>with respect to adaptive advantage" because if he allowed any form
>of determinism into "adaptive advantage", he would be giving eyes
>to his "blind watchmaker" and Paley's watchmaker God would rear His
>ugly (to Dawkins) head:
>
>"According to the doctrines of orthodox Darwinism...the
>"improvements"* in this and all other Darwinian scenarios come from
>gene mutations that are random in the sense that they are not
>directed either by God or by the needs of the organism...This point
>is important because if an unevolved intelligent or purposeful
>force directed evolution, the blind watchmaker would not be blind
>and a supernatural element would be introduced into the system.
>"Evolution" in which the necessary mutations were directed by a
>preexisting intelligence...would be a soft form of creationism and
>not really evolution at all, in the sense in which Dawkins and
>other leading Darwinists use the term." (Johnson P.E., "Reason in
>the Balance", InterVarsity Press: Downers Grove Ill., 1995, p79)
BH>It is interesting that you state that it is 'essential for
>Dawkins to maintain that "mutation is random with respect to
>adaptive advantage" ' and then support this essentiality by quoting
>Johnson! As a matter of fact, Dawkins actually emphasizes the
>point that it is *not* essential.
I used Johnson because I was making a general point. But "as a
matter of fact" I was using Dawkins *very words*" when I said that:
"Mutation is random with respect to adaptive advantage..." (Dawkins
R., "The Blind Watchmaker", 1991, p312).
On Fri, 10 Jan 1997 14:46:50 -0500, Bill Hamilton wrote:
>SJ>But it is the *combination* of "random mutations" with "natural
>selection" that makes the *whole* process essentially random:
BH>This statement is quite misleading. There are a number of
>problems in engineering and the sciences in which the deliberate
>introduction of randomness actually helps solve the problem and
>obtain a better result. Some examples of this are
>
>1. Nonlinear control systems....2. Optimization...3. Adaptive
>control...4. System identification....
I said nothing above about "randomness" ability or inability to
solve some engineering problems, so I cannot see how Bill can say my
"statement is quite misleading", especially since at the end he says
it is in fact "Technically...correct"!
But if there is a "deliberate introduction of randomness", then this
is an analogue of Intelligent Design, not Neo-Darwinist
`blind watchmaker' evolution.
BH>In each of the above cases random noise is deliberately injected
>into a system or process and the result is an improvement in the
>accuracy of the result.
See above. Now all you have to do is find a way for the `blind
watchmaker' to "deliberately inject...random noise...into a system
or process"! :-)
BH>Technically Stephen is correct: the resulting process is random
>in that it contains random elements. However, the uncertainty of
>the final result is significantly _smaller_ than the uncertainty
>that could be obtained without introducing random perturbations.
Bill, after a bit of beating around the bush, including saying that
my "statement" that:
"...it is the *combination* of "random mutations" with "natural
selection" that makes the *whole* process essentially random"
"is quite misleading", actually confirms it is "Technically...
correct" in that "the resulting process is random in that it
contains random elements."
I made no claim about "the uncertainty of the final result" but I
would suspect that the "introducing" of "random perturbations" into
an engineering process by a highly skilled engineer would not
necessarily be a good model of Neo-Darwinist evolution, but might
be a good model of Intelligent Design.
On Mon, 13 Jan 1997 12:10:56 -0600, Steve Clark wrote:
SC>A lottery machine which mixes balls with different numbers, and
>randomly pops a few out of an orifice represents a process and
>outcome that are both essentially random. However, iIf someone
>stands over it and only selects balls that have certain numbers, he
>would be arrested because he is making the outcome unfair and NOT
>random, even though the numbers that the machine generated were
>random.
If an intelligent designer enters the process, then *of course* it
is no longer a completely random process. But this is an analogue
of *Intelligent Design*, not Neo-Darwinist `blind watchmaker'
evolution.
What you have to do in the above example, to make it an anaology of
Neo-Darwinist `blind watchmaker' evolution, is show how a
*natural*, *blind*, *unintelligent* process, could select and
preserve the balls according to a distant target sequence (eg. the
winning lottery ticket number).
SC>Similarly, according to the concept of evolution, mutations may
>be random, but if only certain ones are selected, then evolution
>CANNOT be considered to be random.
Disagree that "evolution CANNOT be considered to be random".
Neo-Darwinist evolution, to the extent that it occurs, must be
always be at least part-"random" because: 1. it relies on random
mutation to generate its initial variability; and 2. even after
non-ramdom "selection", further random mutation, sexual
recombination, and random environmental events can unselect again.
Neo-Darwinism therefore "CANNOT be considered to be" non-"random".
SC>A simple definition of random is a situation in which every
>event has an equal probability. Since, by definition, natural
>selection only permits certain mutations to survive (i.e., to have
>a higher probability of survival than other mutations), the process
>is the antithesis of random.
This is an `Aunt Sally' definition of "random", which Steve sets up
to knock down and claim a quick victory! :-) No one is claiming
that evolution, according to Neo-Darwinism, is essentially "random"
in the sense that "every event has an equal probability". I am
using "random" in the sense that Neo-Darwinists use it, namely of
the sense of not towards adaptive improvement:
"There is a fifth respect in which mutation might have been non-
random. We can imagine (just) a form of mutation that was
systematically biased in the direction of improving the animal's
adaptedness to its life. But although we can imagine it, nobody has
ever come close to suggesting any means by which this bias could
come about. It is only in this fifth respect, the 'mutationist'
respect, that the true, real-life Darwinian insists that mutation is
random. Mutation is not systematically biased in the direction of
adaptive improvement, and no mechanism is known (to put the point
mildly) that could guide mutation in directions that are non-random
in this fifth sense. Mutation is random with respect to adaptive
advantage, although it is non-random in all sorts of other respects.
It is selection, and only selection, that directs evolution in
directions that are non- random with respect to advantage."
(Dawkins R., "The Blind Watchmaker", 1991, p312)
On Mon, 13 Jan 1997 13:39:56 -0500, Brian D. Harper wrote:
[...]
BH>Let me follow here with two goals in mind (1) an illustaration of
>the difference between random and stochastic and (2) to counter
>Steve Jone's claim in another thread that real selection is
>accomplished only by an intelligent agent.
I am not sure that I actually said that "real selection is
accomplished only by an intelligent agent". I do accept that there
is variation and differential survival due to some individuals and
even species being better adapted to the environment. This can be
called "selection" but it is IMHO a potentially misleading metaphor:
"The biologists have innocently confessed that natural selection is
a metaphor, (Barzun, 1964, pp215-216; Hardin, 1961, p61;
Huxley,1957, p34. In the sixth edition of The Origin of Species
(Chapter 4, paragraph 2) Darwin himself referred to natural
selection as a "metaphorical expression" and also said: "In the
literal sense of the word, natural selection is a false term....")
and every experienced person knows that it is dangerous to work with
metaphors. As the road to hell is paved with good intentions, so
the road to confusion is paved with good metaphors. Perhaps the
sober investigators should not have staked so much on a poetic
device." (Macbeth N., "Darwin Retried: An Appeal to Reason",
Garnstone Press, London, 1978 reprint, p50)
BH>This second I'll approach by modifying slightly Steve's (Clark)
>Lottery example since it will be objected to on account of the
>intelligent agent selecting the outcomes.
Good. I did "object" to it "on account of the intelligent agent
selecting the outcomes.
BH>Let's suppose instead that all the balls do not weigh exactly the
>same. Further suppose that the mechanical contraption that selects
>a ball is slightly pre-disposed to select lighter balls. Here we
>have a purely mechanical selection effect, lighter balls are more
>likely to show up than heavier balls. Someone privy to this inside
>information and is able to gain access to the balls to weigh them
>will have a greater chance of winning the lottery than someone
>else. One could also record the outcome of the lottery over a long
>duration and get an estimate of the probability distribution for
>the balls. In any event the sequence of numbers produced by this
>process would not be random in the algorithmic sense but the
>process is still stochastic.
See above. Brian's mechanical contraption only *metaphorically*
"selects" a ball. It has no distant target in mind, like a lottery
ticket number, so it does not really select.
This is still partly random because while it can `select' the
heavier balls, it cannot direct they appear. Depending on how
many balls there are and how many numbers are on the ticket, the
favoured ballIs might never appear to be selected. In any event,
this example seems to have very little relevance to the type of
variation and differential survival that happens in biological
nature.
God bless.
Steve
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