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a challenge to the cladists

I still for all the discussion of cladistics over the last year - and
believe me that has been alot - fail to understand why cladists choose
to ignore an important variable in their analysis.  And given that
most paleontologists doing cladistics are trained as geologists, this
is a failing i really find hard to understand.  WHY DO YOU CHOOSE TO
IGNORE TIME?  It's not as if time is a variable that is obscure.  We
all know that Albertosaurus and Tyrannosaurus did not live at the same
time, yet the cladistic analysis completely ignores this variable.  It
is an easily defined characteristic of the species.  It provides a
reference frame within which to hang the morphological
characteristics.  To me - granted humble geochronologist - this
seems like deciding to analyze motion by only considering distance
thereby ignoring time (makes it very hard to consider acceleration,
speed, etc.)  or like trying do a sculpture using only flat surfaces.

Bonnie A.B. Blackwell,                          bonn@qcvaxa.acc.qc.edu
Dept of Geology,                                off: (718) 997-3332
Queens College, City University of New York,    fax: (718) 997-3299
Dept of Earth \& Environmental Sciences,        fax: (718) 997-3349
The Graduate Center, CUNY,                      fax: (718) 997-3513
Flushing, NY 11367-1597                         messages: (718) 997-3300