On Tue, 1 Jul 97 23:45:54 CDT, Wesley R. Elsberry wrote:
>WE>A population size of 100 and mutation rate of 6% seems to
>provide similar results to those reported by Dawkins.
>SJ>This "mutation rate of 6%" seems to agree with one of ReMine's
>criticisms of Dawkins "Methinks it is like a weasel" simulation
>that has an unrealistically high mutation rate:
>
>"Dawkins did not say, but he must have chosen the mutation rate
>to optimize the speed of evolution. If he had chosen a low
>mutation rate, (such as 10^-8 as in humans) then the simulation
>would require roughly 50 million generations. On the other
>hand, if he had chosen too high a mutation rate, then it would
>cause error catastrophe and the target phrase would never be
>reached. Dawkins picked the mutation rate that produced the
>fastest evolution." (ReMine W.J., "The Biotic Message", 1993,
>p233)
WE>If Dawkins' purpose had been to simulate human evolution
>accurately, then you might have had a point.
A "mutation rate of 6%" still seems far too high for *any
species* to withstand without "error catastrophe":
"Modern organisms get by despite mutations because the rate of
mutation is low. The rate in all organisms from bacteria to mammals
has been estimated for various loci at between 10^-9 to 10^-10 per
base pair copied when DNA is replicated. (Drake J.W., The Molecular
Basis of Mutation, Holden-Day Inc, San Francisco, 1973, Table 5.3).
This is low and infrequent enough to guarantee that all the vital
machinery concerned with the organism's self-duplication, including
its protein synthetic apparatus, can be duplicated perfectly as the
entire system is specified in less than 10^6 base pairs. Moreover,
complex organisms today often exhibit redundancy in the genes
specifying for their essential protein synthetic machinery. However,
if the mutation rate is raised by, say, irradiation, then certainly
this leads to an accumulation of errors down a chain of replication
which is ultimately lethal to the clone of irradiated individuals
(this can be experimentally demonstrated with micro-organisms). When
the mutation rate is very high, no living system can avoid the path
to autodestruction. Each cycle increases the "noise" and erases
crucial information, like a series of increasingly poor photocopies;
ultimately, the text becomes illegible." (Denton M., "Evolution: A
Theory in Crisis", Burnett Books: London, 1985, p267)
Can you cite *any* living organism that has a "mutation rate of 6%"?
WE>However, Dawkins makes clear in "The Blind Watchmaker" that a
>strict analogy with biology was not his intent for the "weasel"
>demo. I suggest that you fire up Interlibrary Loan.
I don't need to. I have "The Blind Watchmaker". And I am well aware
that in the `fine print' at the end of his "weasel" section Dawkins
admits it is not an "analogy" of " real life" evolution:
"Although the monkey/Shakespeare model is useful for explaining the
distinction between single-step selection and cumulative selection,
it is misleading in important ways. One of these is that, in each
generation of selective 'breeding', the mutant 'progeny' phrases were
judged according to the criterion of resemblance to a distant ideal
target, the phrase METHINKS IT IS LIKE A WEASEL. Life isn't like
that. Evolution has no long-term goal. There is no long-distance
target, no final perfection to serve as a criterion for selection,
although human vanity cherishes the absurd notion that our species is
the final goal of evolution. In real life, the criterion for
selection is always short-term, either simple survival or, more
generally, reproductive success. If, after the aeons, what looks
like progress towards some distant goal seems, with hindsight, to
have been achieved, this is always an incidental consequence of many
generations of short-term selection. The 'watchmaker' that is
cumulative natural selection is blind to the future and has no
long-term goal." (Dawkins R., "The Blind Watchmaker", Penguin:
London, 1991, p50).
I have already quoted Berlinski criticism of this as "an achievement
in self-deception":
>WE>The executable is available via anonymous ftp at
>inia.tamug.tamu.edu in the pub directory as "weasel00.exe".
>
>I think that I can easily demonstrate an interest in the "live"
>issue of test by computer simulation.
>SJ>The question is whether it is a realistic "simulation" of the
>biological world.
WE>No, it is not. Read, or better yet buy, the book.
Which book? I have the "The Blind Watchmaker". Your demand that I
"read...the book", seems incongruous when you have criticised ReMine's
Haldane's Dilemma thesis without reading his book.
>SJ>If Dawkins' simulations really did simulate real-world
>evolution, they would be included in every biology book, but they
>are simply ignored.
WE>If cucumbers had anti-gravity, sunsets would be more interesting.
Your evasion is noted! I take it you find my point unanswerable.
WE>Dawkins' purpose for the "weasel" demo was to show the relative
>advantage of a genetic search over a random search. It does
>that quite well.
He didn't need a "demo". Everyone knows that any sort of intelligent
search has an "advantage" over a "random search".
>SJ>The following are some criticisms of Dawkins' "weasel"
>simulation from non-Darwinists (apart from ReMine):
>
>Berlinski calls it "an achievement in self-deception" because
>it uses "a target phrase":
WE>Dawkins brings up this criticism himself on p. 50, so I hardly
>see how Berlinski can call it "self-deception". Maybe
>Berlinski just has reading comprehension problems.
>
>[Berlinski's purple, though unresearched, prose deleted.]
>
>[Further quotes trimmed]
No. Your very calling it a "demo" and an "analogy" (when it is
nothing of the sort), shows that Berlinski is right.
WE>William Dembski brought up essentially the same points that
>Behe made in your quotes when Dembski was at the NTSE
>conference. Dembski's analysis (and Behe's by extension) are
>correct that when no information can be obtained from a
>population, genetic algorithms are reduced to random search.
>The assertion at issue there is whether biological search
>spaces have such binary fitness landscapes. Dembski had
>asserted that one could get non-complex information from random
>search, but complex specified information appearing in
>algorithms was either already inherent in the inputs or was
>infused by intelligence. I challenged Dembski to explain where
>information infusion occurred in a 500 city TSP tour solved by
>genetic algorithm. The searchspace size eliminated
>"non-complex" and the specification of the TSP eliminated
>"non-specified", leaving only "infusion" as a means of getting
>a good solution, according to Dembksi. Dembski responded that
>operating systems and programs had intelligent authors, and
>that one did not get information for free. Perhaps you can do
>better.
I don't need to. Demski response is spot on. All "genetic
algorithm" "programs" do have "intelligent authors" and are provided
with "information" in their design. They are really an anlogy of
intelligent creation and providence, not `blind watchmaker'
evolution.
Regards.
Steve
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