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Re: Re: Linnean Classification and Creationism



>Wouldn't you say that the standard Linnean system of classification with its
>"systematic gaps" between major taxa is a by-product of the the creationist
>assumptions of Linnaeus?  The arguments over what really is or isn't a fish
>or reptile or bird is purely arbitrary since the only really extant
>biological types in nature are genera and species which are the only groups
>which may share a common gene pool. "Higher taxa" were invented for
>convenience in classification and provide little scientific information
>unless you arrange them in evolutionary trees.

Oh, this old chesnut!  Time to trash another beloved gradistic belief: :-)

All monophyletic taxa are real taxa, if we accept that evolution by descent
has occured (I think most of us on the net will agree with that, ne?). As
such, monophyletic lineages exist, and thus clades exist.

Or, from a geneticist's standpoint, clades exist because each monophyletic
subset of species retains (and passes on, if it doesn't go extinct) the
genome of the ancestor.

Only the morphological grade taxa of the past were "purely arbitrary".

>So far neither cladistics or
>phrenetics seems to fullfill that requirement very well because they are
>limited to only morphological comparisons.

Actually, most modern genetic "evolutionary trees" are either parsimony
based (like cladistics) or similarity/dissimilarity based (like
"phrenetics": nice Freudian slip!).

> Maybe we need a combination of
>morphology, physiology, biochemistry, and genetics to do the job right.

This I would agree with!

Thomas R. Holtz, Jr.
Vertebrate Paleontologist
Dept. of Geology
University of Maryland
College Park, MD  20742
Email:Thomas_R_HOLTZ@umail.umd.edu (th81)
Fax: 301-314-9661
Phone:301-405-4084