Re: Are humans irreducibly complex

Brian D Harper (bharper@postbox.acs.ohio-state.edu)
Fri, 04 Jun 1999 13:29:55 -0700

At 08:27 AM 6/4/99 EDT, Bertvan wrote:
> Subj: Re: Are humans irreducibly complex?
>CC: bharper@postbox.acs.ohio-state.edu (Brian D Harper)
>
>>>On Wed, 2 Jun 1999, Bertvan commented:
>>>
>>>> I''d be interested in hearing comments about the
>>>> following web site:
>>>> http://www.scientificamerican.com/0997issue/0997infocus.html
>
>Brian wrote:
>>It is also funny in the sense that creationists often argue that
>>evolution cannot work on account of mutations being random. Now
>>that cases of directed mutation appear to have been documented
>>we find that this is suddenly a problem. How so?
>
>>The important point here is that undirected mutations is not
>>itself a part of neo-Darwinism. Natural selection can work
>>regardless of whether the mutations are random or directed.
>>Further, as the results of this study show, whether mutations
>>are directed or undirected is a question that can be addressed
>>empirically, i.e. it is not just assumed _a priori_ as some
>>creationists have claimed.
>
>Hi Brian,
>
>Directed mutations was not a part of Neo Darwinism as defined in the modern
>synthesis.

Perhaps because all the evidence suggested that mutations were not
directed? The important point is genetic variation. BTW, in the
study you cited, was there selection?

>Someone needs to change the definition and notify the public.

Whether mutations are random or directed is not a matter of definition.

Bertvan:
>If
>mutations are directed, and not random, the roll natural selection plays
>would be unknown-- it might turn out to be a minor mechanism of micro
>evolution, and not responsible for "designing" a single complex organ, body
>part or system. Genetic drift might also be directed and not random--so far
>as anyone knows. Many creationists, those not insisting upon a literal
>translation of Genesis-- certainly many of those promoting a concept of
>design-- would be content with directed mutations. In fact, that has been
>the specific claim all along of one creationist, Lee Spetner, that while
>harmful mutations might be random, the mutations leading to big changes in
>organisms are environmentally directed. Until we know for certain if and how
>mutations are "directed", it seems to me the claim that they are a part of a
>design cannot be ruled out. I realize no one is in charge of definitions,
>which makes this creationist/Darwinist debate so frustrating. Do you have a
>reference I could quote the next time some Darwinist condescendingly explains
>to me: "The mutations are random, but Natural Selection is not; Natural
>Selection is the creative force of evolution."?????
>

One usually sees a quote such as what you give above after a
creationist gives the strawman argument that "evolution is
random". The statement does not imply in any way that mutations
must be random. The point is that even if they are, evolution
is still not random since natural selection is not random.

If you want to read further about an ultra-Darwinian view of
random vs. directed mutations, see <Climbing Mount Improbable>
by Dawkins starting on page 80.

For an alternative to the "...Natural Selection is the creative force
of evolution." part, see the book by Niles Eldredge that I previously
mentioned. His view, with which I tend to agree, is that Natural
Selection is not a creative force nor is it a watchmaker (blind
or otherwise). Instead, it is a passive filter. You seem to me
to be too centered in on ultra-Darwinism. Even if u-D were to
fail completely it would not provide any evidence for design. You
don't find evidence for one theory by knocking down another. This
is a logical fallacy known as the argument from the false alternative.

Brian Harper
Associate Professor
Applied Mechanics
The Ohio State University

"All kinds of private metaphysics and theology have
grown like weeds in the garden of thermodynamics"
-- E. H. Hiebert