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Re: "Cope's Rule" Put to the Test



At 04:02 AM 1/25/97 -0500, George O. wrote:
>I do not, repeat, DO NOT "use Cope's Rule" to support BCF.
        Olshevsky, G., 1994. "The Birds First? A Theory to Fit the Facts," Omni
        16(9): 34-36, 38, 40, 42-43, 80, 82, 85-86 [illustrations by L. Rey].

>Rather, I say that BCF provides an instance of a phylogeny that >follows<
>Cope's Rule and is not an exception to it.
        And this implies that Cope's rule is a workable construct, for which
exceptions must be justified.  No evidence.

>Inasmuch as most tetrapod groups follow Cope's Rule rather than going
against it, this 
>is good for BCF.
        No evidence.

>Inasmuch as the "ground-up" BADD scenario goes against Cope's Rule, this is
>bad for BADD.
        Perhaps it is one of your "exceptions".  Once again, NO EVIDENCE.

>Make no mistake: Cope's Rule works. It certainly doesn't work for bacteria,
>it may not work for molluscs (see Jablonski's paper in the January 16
>_Nature_), and it may not work at certain times and under certain
>circumstances, but over the long run it works for lots and lots of tetrapod
>groups.
        And again I sez, NO EVIDENCE.  If it doesn't work at certain times
and in cerrtain circumstances, it is not going to support your argument.
You must then explain HOW and WHY it works, at which point the HOW and WHY
explanations are more important, and you generalizations are useless.  As
Mickey has pointed out, biology is not geomoetry, which means that evolution
is not a simple equation, and such rules cannot be made, at least without
substantive explanation.
        Bock (in the _Origin of Birds) points out two types of scientific
explanation, nomative(sic?)-deductive (N-DE) and historical-narrative
(H-NE).  Cope's Rule is a twisted version of the latter.  It takes a
percieved historical trend and tries to explain it.  It goes one step
further though and extrapolates that trend out to the whole of evolution.
This, as Bock says, is a no-no.  H-NE are specific to a specific situation
(horse evolution, for example).  N-DE are applicable universally, but are
based on deductive reasoning based on established priniciples.  In many
ways, the pattern of evolution is far too complex to declare that certain
principles will prevail.  By the very fact that you admit to exceptions,
Cope's rule cannot be N-DE.
        As Ron Orenstien (I belive) and I have both pointed out, the
instances of "exceptions" to Cope's Rule which you have pointed out are
indeed instances of selection and speciation.  As has been said before,
unless you are positing an extra-evolutionary force, your arguments are
meaningingless.
 
>The "small, conservative groups" that you say I talk about
>were neither small nor conservative!
        I seem to recall this being a thesis in the above referenced BCF
article.  Perhaps this is incorrect.  Actually, you do specifically insist
on small.  In any case, while you may be correct that groups of small
animals (perhaps even "generalized animals" as you put it) do tend to be
better at exploiting niches, your BCF theory involves a lineage of unusually
conservative arboreal bipeds which just sit in the trees spitting out
dinosaurs, hardly evolving themselves.  While I would be the first to admit
that evolution need not go forth at any particular rate, this is simply an
unlikely, and most unparsimonious hypothesis (containing several
unverifyable and unsupportable assumptions).
        And, like it or not, as Sereno points out in _Dinosaur Systematics_,
parsimony is the tool which scientists use to choose between competing
hypotheses.
        
        Wagner
+--------------------------------------------------------------------------+
| Jonathan R. Wagner                    "You can clade if you want to,     |
| Department of Geosciences              You can leave your friends behind |
| Texas Tech University                  Because your friends don't clade  |
| Lubbock, TX 79409                               and if they don't clade, |
|       *** wagner@ttu.edu ***           Then they're no friends of mine." |
|           Web Page:  http://faraday.clas.virginia.edu/~jrw6f             |
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