Re: Comments on Snoke's approach

From: Robert Schneider <rjschn39@bellsouth.net>
Date: Sat Sep 24 2005 - 15:46:16 EDT

Pim,

Your response to Hunter's note that Darwinian theory is a guided search
process reminded me of a statement that Ursula Goodenough shared with
several of us in a science&religion group. She was criticising Cardinal
Schonborn's NYT essay. I hope she doesn't mind my posting a portion here:

"Cardinal Schoenborn's characterization of evolution as "an unguided,
unplanned process of random variation and natural selection" is an
interesting one to parse.

"The phrasing draws one to conclude that "random" modifies both the nouns
"variation" and "natural selection." In fact, evolutionary theory holds
that the variation is random but that natural selection is the opposite of
random - it is exquisitely choosy. If you have two coupled operations
leading to an outcome, one random and one selective, the outcome will be
selective: If I use a machine to generate random numbers and then ask you
to pick out only those that end in 73, your set of numbers will no longer be
random even though you started with a random set.

"The cardinal draws us to this conclusion because he starts out with two
other adjectives that indicate randomness: unguided and unplanned. By
"unguided" he is of course voicing his own view that "guided" means being
under some sort of supervision by a theistic agent.

"Evolutionary theory works without positing theistic agency so it is not
introduced into the theory - we don't know how to run an experiment in which
a theistic agent is present in one set of observations and absent in the
control set. It does not follow that evolutionary theory rules out theistic
agency. It does not.

[skip here >>>]

"If "guided" is understood not as theistic guidance but just as guidance,
then "unguided" is not a germane adjective for the evolutionary process.
Selective agents, be they environmental conditions or other organisms in the
ecosystem, have everything to do with evolutionary outcomes, and in this
sense they could be said to guide the outcome. Moreover, the same outcomes
keep popping through by numerous pathways: flight, vision, elimination of
metabolic waste, and on and on. That's because the planetary environment
provides opportunities for organisms that can fly, and can see, and can
eliminate metabolic wastes. These opportunities guide evolutionary
trajectories."

Bob continues: Ursula makes the point in another portion of her statement
that we need to help people understand that evolution is NOT "pure
randomness" (as Jacques Monod wrongly stated and every YEC has since
repeated). That is part of the fear, a major part, I believe, that people
have about evolution. As several theologians have asserted, God affirms the
guiding action of nature and works through the secondary cause that consists
of the complex process of variation, environment, and selection.

Bob Schneider

----- Original Message -----
From: "Pim van Meurs" <pimvanmeurs@yahoo.com>
Cc: "Randy Isaac" <randyisaac@adelphia.net>; <asa@calvin.edu>
Sent: Saturday, September 24, 2005 12:33 PM
Subject: Re: Comments on Snoke's approach

> Cornelius Hunter wrote:
>
>> Randy:
>>
>> All this of course assumes that you've got different populations of
>> self-replicating organisms and an environment to start with, but that too
>> runs into this kind of problem. The bottom line is that the Darwinian
>> notion that functional designs are produced by an unguided search process
>> (that just happens to be in place) is not a good scientific theory.
>
>
> Or that the argument is wrong? In this case you are presuming that full
> DNA space needs to be searched. Secondly, Darwinian theory is not based on
> an unguided search process (random search) but rather a guided search.
> Once one realizes that the relevance of the concept of evolvability and
> how evolution itself can evolve one comes to realize why evolution has
> been so succesful. Recent data on protein space helps understand how
> finding functional sequences may not be that hard but let's for a moment
> focus on RNA.
> Scientists like Peter Schuster, Peter Stadler, Walter Fontana and others,
> have looked at RNA and found that it is characterized by a scale free
> nature.
>
> As is well known DNA sequences map to RNA or protein structures.
>
> *
>
> There are far more sequences than structures
>
> *
>
> Contains few highly-connected motifs and many less connected nodes
>
> *
>
> Motifs have a neutral network which extends throughout sequence space
>
> For these frequent structures, their networks expand through sequence
> space, this means that gor any given fold, one can traverse through
> sequence space (that is change every nucleotide position) without changing
> the structure of the fold. In addition these structures are close in the
> sense that any such structure is within a small distance from any random
> sequence.
>
> In other word, given any motif it can be shown that via neutral
> mutatations one can get within one or two non-neutral mutations of another
> motif.
>
> Cornelius' 'thought experiment' presumes that Darwinian theory has to
> search the whole DNA space for it to find functional sequences. Science
> has shown otherwise and thus once again, the Darwinian notion strongly
> supports the data. Of course nothing Cornelius has presented here shows
> that there are limitations to evolution.
>
> In fact the following paragraph still remains mostly unsupported
>
> Cornelius:
>
> You also said that "One could argue effectively that once there exists a
> reproducing organism, the probability that in time there would be a vast
> diverse range of species is close to unity." Again, I don't know how one
> could defend this. Everything we understand about population genetics and
> adaptation points to limits to adaptation. And there is no effective
> argument for how the intricate complexities in biology could have arisen
> from a single cell. All we have are broad speculations based on the
> presupposition that evolution has occurred.
>
> As I have shown some very good hypotheses of the evolution of complexity
> in biology exist. Just recently science provided a link between
> vertebrates and invertebrate eye evolution. Slowly but steadily these
> hypotheses are being strengthened by new data. Not only that, but there is
> few data suggesting that there are limitations to adaptation as envisioned
> by Cornelius.
>
> Scale free networks btw can arise through the simple process of gene
> duplication and preferential attachment. No miracles required. That we
> find lots of evidence of such gene duplication is just icing on the cake
> for evolutionary theory.
>
>
Received on Sat Sep 24 15:48:37 2005

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