Not just in Kansas, Anymore....

[Richard Jensen]

"John R. Grehan" wrote:

> The recent documentation by Richard Pyle on the evolution question included
> assertions by Futuyma that there is more to a good scientific hypothesis
> than corroboration, it must be falsifiable. He then asserts that a single
> undisputed fossil of a flowering plant or human etc in Precambrain rocks
> would do it.

What such a find would do is force us to recognize that our existing view of
evolution is inconsistent with the facts used to support it.  It wouldn't
necessarily cause us to throw everything out.

But, I don't understand the confusion in these postings.  In order to
communicate, we have to agree upon what words mean.  Most scientists use a
definition of theory close to this:  a set of statements designed to explain
what we know. What do we know?  We have at our disposal a great many facts -
observations that have been made repeatedly (i.e., consistent patterns in the
fossil record) and/or can be confirmed by additional testing (e.g., think of
your favorite experiment that is used to demonstrate some basic principle).
Because a theory is designed to explain these related factual observations, it
is often referred to as a fact.

One of the problems in reconciling  a scientist's view of theory with the
general publics' view of theory is that the word is defined differently.  The
general public, and many scientists, confuse the meanings of theory and
hypothesis.  Because we all know that a hypothesis is "an educated guess",
i.e., a statement predicated on prior observation or knowledge, many believe
that a theory is just "a guess."  Ronald Reagan, one of our more "enlightened"
presidents  ;-), felt comfortable dismissing the "theory" of evolution because
a theory is only a guess.  We have to make sure that the public understands
what we, as a scientific community, mean when we refer to a theory.

In the same vein, I know that many take the view that science is akin to
religion because scientists use the word "believe" quite liberally.  Again,
there is a fundamental difference between a scientist's use of believe and the
use of believe in a religious context.  When a scientist says, "If I mix HCL
with some zinc filings, I believe that the result will be the production of
zinc chloride," that is not the same as someone saying that "I believe the
story of Genesis as a literal truth."  The former is based on uncounted
empirical observations that that is exactly what will happen and "believe"
should be equated with "know".  The latter has no empirical foundation - it's
simply a matter of choice and anyone can arbitrarily decide to accept Genesis
as a true account or not.  As I tell my students, scientific theories are not
open to arbitrary acceptance - you may say you reject theories of gravitation
(and the laws accompanying them), but neither nature nor God is going to be
very forgiving if you choose to "believe" you won't fall (another favorite is
the speed of light - it's not just a good idea, it's the law!)

Evolution, as a scientific theory, has the same status as all other scientific
theories: it allows us to construct testable hypotheses and the results of
these tests can be used to either refute or modify the theory (i.e., it is
falsifiable).

Cheers,

Dick

--
Richard J. Jensen              TEL: 219-284-4674
Department of Biology      FAX: 219-284-4716
Saint Mary's College         E-mail: rjensen at saintmarys.edu
Notre Dame, IN  46556     http://www.saintmarys.edu/~rjensen