From: livesey@solntze.wpd.sgi.com (Jon Livesey)
Newsgroups: talk.origins
Subject: Re: Topic for Discussion?
Date: 27 Jan 93 07:09:35 GMT
Organization: sgi
NNTP-Posting-Host: solntze.wpd.sgi.com

In article <1993Jan26.083653.9970@smds.com>, rh@smds.com (Richard Harter) writes:
|> In article <1k1ri0INN2t7@fido.asd.sgi.com> livesey@solntze.wpd.sgi.com (Jon Livesey) writes:
|>
|>
|> Point taken.  As noted above, I didn't read the whole post.  Jon
|> is justified in pointing out that he addressed the issue.  However
|> I am now confused.  What do you mean by an "escape"?  Do you mean
|> an escape from any sort of representation whatsoever?

I mean pretty much what I say above.   I mean an argument that
says "Well, micro-evolution doesn't actually consult a species
representation, it's just that eventually cumulative
micro-evolution produces non-functional organisms."   That is,
an appeal to the concept of viability.

In fact, as I say above, that's not an escape in fact, because
the same argument that applies if the information such a
change-limiting mechanism depends on is partly in the
environment, and not all inside the organism.   As I am
pretty sure it must be.

|>
|> |As I said above, even if you think viability is the key, viability
|> |is itself a form of representation, because viabilty is the interaction
|> |between the organism and its environment, and because the environment
|> |changes, the "allowed states" in this interaction also change.
|>
|> I would have thought that it was clear that I treated viability as
|> a form of representation.

In that case, as I said, the argument that appeals to viability
is not an escape, since the environment changes over time.

|> The fact that, as the environment changes,
|> the "allowed states" change, neither establishes nor negates the
|> possibility that the region of viability is bounded.  Later on in
|> the posting you seem to agree.

I think, once again, that you are misunderstanding.   Yes, of
course in individual cases the region of viability may be bounded.

There are three cases here:

   1.   The creationist claim that cumulative micro-evolution
        can *not* lead to micro-evolution, because of some
        built-in limiting mechanism.

    2.  The claim that cumulative micro-evolution *always* leads
        to macro-evolution.

    3.  The claim that cumulative micro-evolution *can* lead
        to macro-evolution.

To show 2. I would have to show that there is *always* a region
of viability.  But I am not trying to show 2.  I am trying to
show 3. and to do so, I have to show that you can't prove that
the region of viability is always bounded.  In other words, in
*some* cases, cumulative micro-evolution can lead to
macro-evolution.    [In other cases it simply leads to stasis or
extinction].

|>
|> ||> That is, a particular
|> ||> "kind" may be intrinsically limited in the range of variants that
|> ||> are viable.
|>
|> |You are making the same error that Mr Chow made, which is ironic,
|> |since you just posted for him.
|>
|> Since you don't say what error I am making, it is rather difficult
|> to tell what you are talking about.  In the quoted sentence I use
|> the word "may".  I am not taking a position; I am merely pointing
|> out a possibility.

You and Mr chow are both pointing out that a *particular* kind may be
limited in the micro-evolutionary steps it can take.   That does not
have much to do with whether there is some intrinsic limit to
micro-evolution in general that prevents it *ever* leading to
macro-evolution.

Incidentally, I don't exclude that macro-evolution occurs through
other mechanisms as well.

|>
|> |What I am saying is that you can't show that micro-evolution can't
|> |lead to macro-evolution *in general*.
|>
|> |Try to think of that "in general" some more.   What I am saying has
|> |nothing to do with what happens to a particular species.   It has
|> |to do with a general claim that there is some intrinsic "limit"
|> |to micro-evolution.
|>
|> The problem here is that it is not clear what you mean by *in general*.
|> If you merely mean that one can't show this as a theoretical result,
|> independent of specific knowledge, then one could scarcely argue.

We are starting to agree.    This discussion started a while back when
first Mr Bales, and later Mr Tun claimed that there was what they
called a "built-in" limit to micro-evolutionary change, which prevented
it from leading to macro-evolution.

|>
|> But, in the case of life as we know it, you haven't made your case
|> as far as I can see.  For any genome, either there are some environments
|> in which organisms having that genome are viable, or there are no
|> such environments.  [Or do I have a false dichotomy? :-)]  Now it
|> it at least logically possible that one could actually determine
|> which genomes were potentially viable and which were not, and that
|> genomes when restricted by potential viability formed disjoint bounded
|> sets.

Now you are back to particular genomes.    Showing that in fact a
particular genome got itself into the state where further
micro-evolutionary changes led to non-viability is what I would
expect.  However, I don't expect that to be the case for all genomes.

|>
|> In short, I am not claiming that I or anyone else can establish that
|> micro-evolution cannot lead to macro-evolution.  I am disputing the
|> claim that, in principle, no proof is possible.  Of course you may
|> not be making that claim, but if anyone is making it, then I dispute
|> until such time as the converse is demonstrated.

The most effective rebuttal would be to sketch a mechanism
that can limit micro-evolutionary change, and prevent it from
resulting in macro-evolutionary change.

|> |Another misquote.   There does not have to be an explicit representation
|> |of the species.    However, if you hold that cumulative micro-evolution
|> |*cannot* lead to macro-evolution, then you have to appeal to some
|> |mechanism to implement this limit.
|>
|> Agreed that you didn't claim an explicit representation.  I'm afraid
|> that I can't accept a statement "have to appeal to some mechanism"
|> without clarification of what you mean by a mechanism.

Oh, no you don't.   The claim that there is such a mechanism
is not mine.    It's a creationist claim, and I know perfectly
well that if I ever suggest what such a mechanism might be, and how
it would not work, the response will be a polite "But that's not
exactly what we meant".

If the creationists think that there is such a mechanism, let them
present it.

|>
|> Unless, of course, the limitation is implicit in the laws of biochemistry.
|> I have no idea whether you classify the laws of nature as a centrally
|> controlled representation.

Or if there is such a limit implicit in the laws of biochemistry.

|> |What I was dicussing is a different topic.   Not whether cumulative
|> |micro-evolution *has* lead to macro-evolution, which is simply an
|> |evidentiary matter, but whether one can sustain the claim that
|> |cumulative micro-evolution *cannot* lead to macro-evolution.
|>
|> What you say is true; you discuss what you discuss.  Per your discussion
|> there are two different considerations, to wit: Has anyone sustained
|> such a claim, and is it even possible, in principle, to sustain such
|> a claim.  As to the latter, IMHO, you haven't made your case.  As to
|> the former, as far as I know, no-one has done so plausibly and I see
|> no prospects of anyone ever doing so.

As I said above, there is an effective rebuttal.

|>
|> However I should like to point out that, IMHO, the point that you are
|> trying to establish is irrelevant to the issue of Creationism/Evolution.
|> The Theory of Evolution makes the positive claim that macro-evolution
|> has occurred and that it is the result of cumulative micro-evolution.
|> The burden of proof is on the side of the Theory of Evolution for
|> establishing both the theoretical possibility and the practical feasiblity
|> of macro-evolution via cumulative micro-evolution.

Not hardly.    The claim I am addressing is the positive claim that
cumulative micro-evolution cannot lead to macro-evolution.   I suppose
I may address such claims.

|>
|> It is a legitimate tactic for opponents of Evolution to raise the issue
|> of the potential lack of such proof.  It obligation of the proponents
|> to provide it.

I'd suggest it is equally legitimate to address the claims that they
make.

jon.