Fwd: Re: Why is taxonomy placeless? (My overview)

John Grehan jrg13 at PSU.EDU
Sun Feb 3 14:23:37 CST 2002

>>follow huge mass extinctions, in particular the end-Cretaceous (K-T)
>>extinction.  I believe that the northern hemisphere was almost wiped clean
>>of mammals and birds,

What is the biogeographic evidence for such an assertion?

>>     The southern hemisphere was also devastated, but it was in southern
>>Gondwanaland that a number of mammal and bird clades managed to survive,
>>repopulated Gondwana in the earliest Paleocene, and then quickly spread
>>north (radiating explosively as it went).

Again what is the biogeographic evidence for such a scenario? (It's ironic
here that
some New Zealand Darwinians are claiming the speculated impact was as great in
the southern hemisphere as the north  - leaving nothing for nobody!

>>    Note that only the "marine" afrotherians (sirenians and the extinct
>>desmostylians) seem to have successfully spread to the New World.

Biogeographic evidence?

>>without a known phylogeny, who would have guessed that the desmostylians of
>>western North America and Eastern Asia were actually afrotherians?

Please explain

>>Phylogeny trumps biogeography, and the latter will almost always play second

Have to disagree here. Phylogeny does not of itself determine what kind
biogeography one does, and different biogeographic methods with the same
phylogeny can give very different results.

>>The paleognaths (ratites and tinamous) have held on in the south, but

They also have done fine in the northern hemisphere.

>>biogeographic patterns, because these are often of considerable value.  John
>>Grehan certainly has his hands full trying to remedy the tendency to dismiss
>>biogeography as relatively unimportant.

Which was just done above by the claim that biogeography plays second fiddle!

>>Using a balanced approach, they can
>>usually complement one another quite nicely.

"Balanced" is a propaganda term used for political purposes (in politics of
Gould used the same propaganda to defend Darwinism.

>>All approaches have their
>>limitations, so one should never put all of your eggs in one basket.  That
>>is why I like being an eclecticist, which allows you to diversify your
>>"portfolio of ideas" to the greatest extent.

Again - a political viewpoint on the nature of science.

John Grehan

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