From: Keith Miller (kbmill@ksu.edu)
Date: Sun Oct 19 2003 - 19:08:54 EDT
Don Winterstein wrote:
> Keith Miller wrote:
>
> "Any accepted scientific theory is simply the best existing
> unfalsified explanation for the observations already made. This is as
> true for physics as it is for evolutionary biology."
>
>
> Keith, I liked your post and mostly agree with it, but for my
> edification I'd like to hear your (or anyone else's)responses to two
> sets of questions:
>
> (1) Given what we know about Mercury's orbit today, wouldn't the
> inability of Newton's theory of gravity to account for the motion
> constitute falsification? That is, Newton would predict one thing,
> and we'd observe another. Yet, if we didn't have an alternative such
> as general relativity or something similar, wouldn't physicists still
> accept Newton even though he'd been so falsified?
I will let our physics colleagues respond to this. I do not know
either the science or the history of physics well enough to
intelligently respond.
> (2) Support for the mechanisms of historical organic evolution as I
> understand them all come under the heading of plausibility arguments.
> That is (to grossly oversimplify), a number of genetic mutations
> occurred in an environment that weeded some out but kept others; this
> all happened in the past and can't be tested, but because we see the
> end result, it must have happened that way. Do you know how to
> falsify such plausibility arguments, or whether they can be >
> falsified?
To address the issue of falsifiability requires that the the topic of
discussion be very clearly defined. "Biological evolution" is an
incredibly broad unifying scientific concept. It consists of a large
array of proposed mechanisms and draws on a wide range of observational
data from geology, paleontology, ecology, population biology, genetics,
developmental biology, etc, etc. The subsidiary theories make testable
predictions in these various disciplines. And in response to new
observational data and experimental evidence these theories are
continually being modified and in some cases largely discarded.
My own field of paleontology has seen a number of spectacular fossil
discoveries within the past 10 years. Some of these have confirmed
previous theories about the pattern of evolutionary relationships
derived from anatomical and genetic data of living species (see my
chapters in the edited volume "Perspective on an Evolving Creation").
Other theories have been discarded as new data has been made available.
It must also be remembered that there is a variety of types of
scientific hypotheses. Some make very clear predictions which can be
relatively easily be tested. Others make predictions that are not as
easily or unambiguously tested. Others are highly speculative and may
be properly thought of as plausibility arguments.
With regard to evolutionary mechanisms -- the validity and importance
of such mechanisms are being tested in field settings, in the lab, and
by computer modeling. Furthermore, the occurrence of past genetic
events such as gene duplication events, chromosomal rearrangements,
lateral gene transfers, etc. can be identified within the genomes of
living organisms. More generally, the patterns of genetic similarities
in living organisms provide a record of past genealogical
relationships. Conclusions based on these observations can be tested
against observations from the fossil record.
I do not have time here to address the issue raised by your statement
"... this all happened in the past and can't be tested... ." As a flat
statement, this is simply not true. As a geologist, I make predictions
all the time based on my reconstruction of past events. Every time I
examine a new outcrop I am very consciously testing those
reconstructions. If the new observations don't fit, I am forced to
construct a new model. I have written a PSCF article some time ago
that addresses the issue of testability in the historical sciences. It
is entitled: "The similarity of theory testing in the historical and
"hard" sciences" (PSCF, vol 54, no.2, p.119-122)
Keith
Keith B. Miller
Research Assistant Professor
Dept of Geology, Kansas State University
Manhattan, KS 66506-3201
785-532-2250
http://www-personal.ksu.edu/~kbmill/
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