EVOLUTION AND BIOLOGY
Dobzhansky was saying that the fact that evolution
occurs explains the interrelatedness of the various facts of biology,
and therefore makes biology make sense.
Dobzhansky said, "Seen in the
light of evolution, biology is perhaps intellectually the most
satisfying and inspiring science. Without that light, it becomes
a pile of sundry facts, some of them interesting or curious, but
making no meaningful picture as a whole."
Seen in the light of evolution, biology is, perhaps, intellectually the most satisfying and inspiring science.
Without that light, it becomes a pile of sundry facts -- some of them interesting or curious, but making no meaningful picture as a whole.
ABT 25:125-129, p. 129
Let me give you a quick example. One area where
we tend to teach "sundry facts" is in taxonomy. Right,
you all know that....kingdom, phylum, class, etc.. What we're
saying here is that species can be grouped into genera; genera
can be grouped into families; families can be grouped into orders
and so forth. The Linnaean system is really a system of nested
Why is it this way instead of some
other way? Why is it that families can be grouped into orders;
orders can be grouped into classes; classes can be grouped into
phyla? Well, most textbooks, although they are getting better,
present sundry facts to to memorize. If a creature has warm blood,
bears its young alive, has a single bone in the lower jaw, we
put it into the group mammal. If it has jointed legs, it is an
arthropod, we put it in some other group. Kids memorize all of
this, but they are usually clueless as to why we can group organisms
by similarities and differences of characteristics in the first
We should let students in on the secret. We
don't classify organisms together because they look alike. Putting
things together because they look alike is sorting. Ladies and
gentlemen, if you start your class on evolution out with a pile
of shoes or a pile of nuts and bolts and have the kids classify
them, wrong. You are misleading your students. You are having
them sort stuff. Shoes don't reproduce. That is the big difference
between sorting and biological phenomena.
The car example. There is a whole bunch of
textbooks that say "have students classify cars and show
the evolutionary relationships of tail fins" or something.
Wrong. This is completely backwards! It is really misleading kids
on what evolution is all about. All creatures with a single bone
in the lower jaw aren't grouped into mammals because they have
this character, they are grouped into mammals because mammals
are defined as the descendents of a creature way back when that
had a single bone in the dentary. And that is why all of these
creatures are mammals. Not because they have the character, but
because they inherited this character from a common ancestor.
The reason all these creatures look alike is
that they share a common ancestor. Evolution provides the missing
bit of information that makes classification and animal diversity
Organisms can be grouped in a hierarchical
arrangement like that slide because the branching process of evolutionary
change produces this nested hierarchal arrangement that you see
in taxonomy. Evolution makes both the diversity of structure
and the fact that you can group organisms according to structure
make sense instead of a pile of "sundry facts". And
this is why evolution is so important to biology and why the first
Bioforum of 1997 is focusing on this topic. There are many other
reasons too, but we don't have time to go into them.
Evolution is obviously very important to the
California Science Framework, and if you look at any of the national
programs for science education reform, the Benchmarks, the Project
2061, the National Science Education Standards, any of these will
have a very prominent place for the idea of evolution. Just to
take the National Science Education Standards as an example, under
the Unifying Concepts and Processes, we have here "Evolution
and Equilibrium" one of the very prominent ones. Unfortunately,
not everyone is as enthusiastic as teachers are about teaching
evolution. Which is another reason why evolution is the theme
of this first Bioforum session.