From: rh@smds.com (Richard Harter)
Newsgroups: talk.origins
Subject: Re: Topic for Discussion?
Date: 25 Jan 93 06:14:59 GMT
Reply-To: rh@ishmael.UUCP (Richard Harter)
Organization: Software Maintenance & Development Systems, Inc.

In article <1jq3p3INNa89@fido.asd.sgi.com> livesey@solntze.wpd.sgi.com (Jon Livesey) writes:

>Suppose you hold that macro-evolution and micro-evolution are in
>some sense different in kind.   Perhaps you believe that macro-
>evolution takes place through a mechanism which is different to
>"cumulative microevolution".       Perhaps you hold that there
>is some "limit" to micro-evolution which would prevent cumulative
>micro-evolution producing macro-changes.

>Then the question is, how is this limit implemented?   If there
>is to be some mechanism to prevent micro-evolution producing
>cumulatively greater and greater changes, there has to be some
>information stored somewhere which tells the mechanism of micro-
>evolution, in effect, "this far, and no further".

>In other words, starting from a species, there has to be a form
>of representation of that species against which some future
>variant can be compared, in order to see if the putative
>micro-evolutionary step at that time is "allowed".

>Where to store this representation?   It can't be stored
>centrally, outside the organisms - unless you believe in
>Sheldrake's informational fields - so it must be stored inside
>the individual organism, one copy per organism.

Stop right there.  This is the fallacy in your argument.  [It's
a nice argument though -- are you trying to see if people will
catch it?]  The fallacy here is the false dichotomy -- the
presentation of two alternatives with the claim that they subsume
all cases.

Now quite obviously, if one thinks on it a bit, it is conceivable
that the limit [if it exists] is viability.  That is, a particular
"kind" may be intrinsically limited in the range of variants that
are viable.  I use the word "kind" advisedly because if this were
the case then it quite conceivable that a "kind" might actually
involve a number of species.  Now the interesting thing here is
the steps that Jon takes.  The first step is to infer that, if 
there is a limit, then there must be a mechanism.  So far, so
good.  The second step is to infer that there must be a representation
aand a comparison.  This step in his argument is misleading; it leads
us to think in terms of an explicit representation stored in the
form of information and an explicit comparison mechanism.  Once
we accepted this implicitly suggested limitation we are led down
the garden path to Jon's refutation, because we ask where can this
information be stored, and the answer is that there is no plausible
place to store it.

The catch is that there need be no explicit representation anywhere.
The constraints (again, on the assumption that they exist) are
implicit in the environment and in the laws of nature.  Likewise,
the mechanism is not explicit -- those variants outside the range
of viability die.  No explicit "comparison" is needed.

The question of the limits to macro-evolution is one of fact; it is
not an issue that can be settled by theoretical arguments alone.  It
is the weight of an overwhelming preponderance of evidence that
establishes that macro-evolution has occurred.
-- 
Richard Harter: SMDS Inc.  Net address: rh@smds.com Phone: 508-369-7398 
US Mail: SMDS Inc., PO Box 555, Concord MA 01742.    Fax: 508-369-8272
In the fields of Hell where the grass grows high
Are the graves of dreams allowed to die.
Newsgroups: talk.origins