evolution in KS

Bruce Walsh jbwalsh at u.arizona.edu
Thu Aug 12 20:37:12 EDT 1999

A few comments on two recent Leps-list posting about the KS Evolution
vote to potentially clear up some misconceptions.

First and foremost, evolution, that all known organisms have the same
common ancestor (and that groups of related organisms thus share a more
recent common ancestor to each other than to other groups),  is a scientific

A bold statement, but it is just as correct as saying that the earth is
round.  How do we know the earth is round?  Because we have made
measurements and tested to see if this were true.  Likewise, we test to see if there
is evidence for organisms having common ancestors.  The evidence is
overwhelming, and comes from very many different approaches, most recently from
molecular studies.    For example, if you compare a bat, a bird and a
whale,  given their overall build and what they do, the expectation is that
the bat and the bird would have closer biochemistry.  However, the
PREDICTION from evolution is the whale and that bat will have closer biochemistry
than the bat and the bird.  Indeed this is the case.  Every time a new
gene is sequenced, it is a TEST of evolution.  The theory has been thus
tested literally close to a million times, with all results showing that all
organisms examined indeed share common ancestors.

Thus, John's comment that "at least what I have seen about teaching
evolution is the obsession with evolution having occurred or evolution being a
fact rather than evolution as a scientific research program."    In fact,
evolution is the result of a scientific research program, one that is
still very active today in that evolution is always being tested.

There are any number of  observations which, if repeatable, would cause
me to question evolution as we know it (such as finding an organism with no
obviously common ancestry with any life form).  Hence, evolution is
science because it (1) makes predictions and thus (2) is testable, in
particular, it is (3) falsifiable --- we can reject the theory if certain
observations are found.  When no such observations are seen after 100+ years of
testing, we feel awfully darn good about it.

In constrast, if one believes in the strict creationist model, ask them
if there is any observation that would case them to question their own view
--- likely not.  Evolution is science because be we always challenging it
as to whether or not it is correct.  Contrary to the general view, it is
not taken on faith.  Conversely, creationism works by not TESTING or
trying to falsify their world view, but rather by making odd statements
(usually incorrect and almost always misleading) about evolution.  Creationists
take their view on faith and try to knock down other ideas, rather than
having the stones to test their own theory.

The reason this topic is timely for the leps-list is that when we say
this butterfly is (say) a swallowtail or  a skipper, we are talking about
groups of organisms with a recent common ancestor.  If each species of
swallowtail were independently created with no shared ancestor to any other
species, we would not expect them to share other features as well.  Yet they



Bruce Walsh
University of Arizona
(evil Evolutionary Geneticist)

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