[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

On the subject of "arbitrary" paleontology



Brian (Philidor11@aol.com) said:
"A scientist working on a problem in 
physics or chemistry can in many cases observe the entire problem
being 
investigated in a lab.  The data needed to produce a solution can be

identified and, with effort, obtained.
Paleontology works with objects which at present can be in only one
place at 
a time, the data are obviously incomplete, and the only way to get
additional 
information is to wait and hope.  Inference has to be piled on
inference, and 
a number of sciences and techniques have to be applied by the same
individual 
to produce...an interpretation of the evidence."

This is a large misunderstanding of the scientific method in
historical sciences.  Paleontology is not an experimental science, in
the sense that physics or chemsitry is.  You are right, we don't have
controls, we have many filters to deal with, etc.

However, we're doing more than just making inferences upon inferences
as interpretations of evidence.  As I've said before on this list, all
good science postulates hypotheses that have four rules: 1)
testability; 2) repeatability; 3) falsifiability; and 4) predictive
power.

If a paleontologist observes a number of different animals in museum
collections, notes various landmarks and characters, and produces a
cladogram, that is indeed a testable hypothesis.  Other scientists can
go back and look at what he/she did, this making it repeatable.  If
they get similar results, the hypothesis has failed to be falsified,
but can still be at any time.  This hypothesis of relationships also
has predictive power: it predicts relationships of the animals and may
suggest where to look for relatives or outgroups.

So while we don't do experiments in the traditional sense, we are
very much doing science and not just inference on inference as we see
fit.

To continue:
"The assumption is that 
unassailable rules can be found in each situation and that an
arbitrary 
measure (such as, in a different context, a foot) can be replaced
with an 
objective measure (a meter)."

There is no assumption of unassailable rules, but we all have to make
assumptions.  Otherwise, we would be re-inventing the wheel every day
and getting nowhere.  I assume that the Theory of Evolution by Natural
Selection is at work when I work with dinosaur evolution or
biomechanics.  I assume that it does based on the evidence I have been
presented from peer-reviewed scientists and the evidence I have seen
first-hand.  By the same token, I assume for now that cladistics is
the best tool to sort out fossil relationships until a better tool is
proposed and accepted.

This talk of arbitrariness is interesting.  You use a foot as an
example of an arbitrary character and a meter as an objective measure.
 But why would so many people select foot and limb characters in
dinosaurs over others?  Why not pick anything?

Because, dinosaurs are archosaurs which became bipedal early in their
evolution and thus major changes occurred in their limbs that set them
aside from other archosaurs at the time.  We could have picked
vertebrae spine shape or length of tail, but these characters would
not have helped us very much.  While I am not denying that
subjectiveness takes place in this science as in all sciences, are we
to just give up entirely?  Is everyone's classification just as good
as anyone else's?  And, if so, what is the point of any of this?  We
may as well be arguing about which dinosaurs looked neat and which
didn't.

But if that were the case, why, over hundreds of years of
classification, using different systems, should there be such a strong
consensus on the relationships of organisms on this planet?  Doesn't
it amaze anyone on this list that for all the arguing (which is
healthy for science, I might add) over who is related to who, no one
doubts that birds are archosaurs, or that dinosaurs, birds, and
crocodiles are all related, or that they are all vertebrates?  If our
classification system, no matter which you prefer, was so arbitrary,
there should be little consensus, except among rival interest groups. 
And even here, when you consider how many scientists exist all over
the world, under different poltical, social, and religious
backgrounds, the amount of disagreement should be enormous.

Instead, there is a world-wide scientific consensus on how organisms
are related to one another, a large portion of which is drawn from the
"arbitrary" and "logical argument" findings of paleontology.  Where
does this agreement come from?  Is it from the secrect society of
scientists, who agree to back each other and ignore contrary data?  No
way.  It is because in paleontology, like all science, we set up
testable, repeatable, falsifiable, and predictive hypotheses.  These
can be tested against physical evidence, and judged on their merits by
anyone.  Hypotheses that stand up to old and new evidence alike
through their testing and repeatability, tell us something about the
real world.  This, ultimately, is what we are trying to do in
paleontology.

Matt Bonnan
Dept. Biological Sciences
Northern Illinois University