george murphy wrote:
>
> pruest@pop.dplanet.ch wrote:
>
> > george murphy wrote:
> > >
> > > pruest@pop.dplanet.ch wrote:
> > >
> > > > Jonathan Wells' "Icons of Evolution" has been criticized repeatedly and
> > > > recommended a few times on this list. J.A. Coyne's rabid criticism,
> > > > "Creationism by stealth", Nature 410 (12 April 2001), 745-746, has also
> > > > been mentioned.
> > > >
> > > > In Reasons to Believe's Facts for Faith issue 5 (1/2001), pp. 60-61,
> > > > Fazale R. Rana provides a very much more sympathetic discussion of
> > > > "Icons".
> > >
> > > There is no single set of observations &/or experiments which _prove_
> > > biological evolution in general or a particular theory of biological
> > > evolution. That's the case with any scientific theory & is especially so
> > > with one like evolution in which a great deal of the relevant phenomena were
> > > in the past. In addition, any number of theories can be developed to
> > > explain a given observation. _Ceteris paribus_, the best theory is the one
> > > which explains the widest range of observations with the fewest number of
> > > _ad hoc_ &/or untestable hypotheses. A number of the following criticismss
> > > are effective only to the extent that the experiments or observations are
> > > supposed to be "proofs" of evolution rather than evidence which is
> > > supportive of it. In particular ...
> >
> > I agree with your basic concept of a scientific theory and it's (lack
> > of) general provability. I don't expect textbooks to give "proofs" for
> > evolution, and I consider neither Wells' nor my objections to be
> > "proofs" against evolution. However, we should expect textbooks
> > presenting evidence for evolution to select the strongest pieces of
> > evidence available. If all of what they provide is either irrelevant, or
> > ambiguous as evidence, they aren't doing a good job. The crucial point
> > is that evolution usually is presented as an undisputable fact, and not
> > just as the theory "which explains the widest range of observations with
> > the fewest number of _ad hoc_ &/or untestable hypotheses".
>
> Yes, evolution should be presented not as unqualified "fact" but as theory. I
> would add that it is the best scientific theory - in the sense I stated above - of
> the development & history of life we presently have.
> All observational evidence for a theory is "ambiguous" to some extent: It
> is very hard to think
> of a single observation or single class of observations which can be explained by
> one and _only_ one theory. It may be, e.g., that the homology of vertebrate limbs
> can be explained by theories that don't involve common descent. That does not,
> however, mean that such homology is not supportive of evolution _when taken
> together with other observations and experiments_. A theory which is a viable
> competitor of "standard" evolution must be in accord not only with homology but
> with all the other evidence which is supportive of evolution.
> E.g., textbooks often cite the excess precession of perihelion of
> Mercury's orbit as evidence for Einstein's theory of gravitation. It would be
> wrong to say that perihelion precession itself "proves" general relativity: There
> are a number of alternative theories which do that as well. But when the totality
> of observations (light defelection, gravitational wave damping &c) are considered,
> it's pretty clear that Einstein's theory does the best job of explaining them all
> with the fewest arbitrary assumptions.
I agree with your characterization of a scientific theory and its
supporting evidence. However, it strikes me as inappropriate to compare
the theory of "the development & history of life we presently have" with
Einstein's apparently very well supported theory of gravitation. True,
we have a very extensive set of data regarding the history of the Earth,
the fossil record, similarities on all levels, and the mechanism of
microevolution, and all this taken together (together with biblical
arguments) definitely points to a common descent of all biological life.
But we have virtually nothing but speculation about the origin of life
and the mechanisms of macroevolution, both of which are fundamental to
biological evolution. (I define macroevolution as originating novelty -
a structure that in its minimal selectable form is beyond nonselected
mutational random walks within the time and with the resources
available.) I don't take this as an argument for claiming that evolution
is not a reality - I think it is. But the mere belief that it has indeed
happened is no reason to confound micro- and macroevolution, which
implies a huge extrapolation. The mechanism of mutation (all types of
compound genetic changes included) and natural selection is woefully
inadequate to generate functional information. In this sense, the theory
of evolution, lacking its crucial constituent, doesn't "explain" the
observations at all.
> > In fact, the
> > principal untestable hypothesis assumed is philosophical naturalism. The
> > power of the evidences for evolution depends very much on the previous
> > assumption of theism or atheism.
>
> This is true only in the sense that scientists assume that God is not an
> element of scientific explanation - i.e., what has been called in a rather loose
> way "methodological naturalism." Most scientists who are Christians operate in
> this way whether they have thought out their assumptions carefully or not. (No
> competent scientist, when confronted with a puzzling result of an experiemnt, will
> be content to explain it by saying "God did it.") Moreover, one can present good
> _theological_ arguments to validate such "methodological naturalism."
> It is quite another matter - and I think simply untrue - to say that this
> is equivalent to an assumption of "atheism" in the ordinary sense of the word.
I don't posit a god-of-the-gaps. In theory, "methodological naturalism"
may be the ideal for both atheistic and theistic scientists (in their
science). But in practice, atheists are much less likely to recognize
and concede that the origin of life and macroevolution pose
informational problems. How should one be able to ever find a scientific
solution to these problems if one doesn't even acknowledge them as such?
In this area, talking about "emergence", "self-organization", "hierarchy
theory", "generation of information" and the like is just so much
hand-waving. Dembski's filter and Behe's mousetrap may not be the proper
way of doing it, but somehow we have to deal with the problem of
information if darwinian evolution is not to be left dangling in the
air.
Peter
-- -------------------------------------------------------------- Dr Peter Ruest Biochemistry Wagerten Creation and evolution CH-3148 Lanzenhaeusern Tel.: ++41 31 731 1055 Switzerland E-mail: <pruest@dplanet.ch - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - In biology - there's no free lunch - and no information without an adequate source. In Christ - there is free and limitless grace - for those of a contrite heart. --------------------------------------------------------------
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