More on Biogeographic memory

P.Hovenkamp Hovenkamp at NHN.LEIDENUNIV.NL
Thu Oct 18 12:36:09 CDT 2001

I'm beginning to have some difficulties keeping up a three-cornered
conversation in this way (not meaning I don't enjoy the exchange of
opinions. I think we are beginning to understand one another).
So just a few remarks while I sort out a more coherent reaction on the
criticisms about "Pattern biogeography" which I find myself
(understandably) accused of...
At 03:12 PM 10/16/01 -0400, John Grehan wrote:

>>Perhaps the confusion is in the use of the word "synapomorphy"? To me, the
>>use of the word synapomorphy suggests going all the way from primary
>>homology assessment via phylogeny reconstruction to recognizing
>>synapomorphies on the preferred tree. I realize that with a more
>>restrictive view of synapomorphy ("derived similarity") the whole
>>discussion may seem to be pointless...
>I have not delved deeply into the philosophical/methodological issues of
>synapomorphy in biogeography and systematics so I cannot offer more than my
>current understanding of the baseline as a synapomorphic character for

Why then did you pick the word "synapomorphy"? Possibly other words would
have conveyed your meaning more unproblematically...

>I would agree that its a subject that could warrant further
>evaluation and investigation by those so interested.

There again we have reached agreement!

>>To John Grehan: If the Indian Ocean is one tectonic feature,
>Actually the Indian Ocean is a geomorphological feature.
>>you can expect to find the a single consistent pattern - if it is not, you
>>may find different general patterns involving the northern and the
>>southern part...
>No problem.

But that does not answer my problem - I am afraid that by "lumping" all
tracks under a single "Indian ocean" baseline, you will never be able to
find different general patterns.

>>>Except spatial evidence through baseline homology apparently does not
>>>constitute evidence at all in your view.
>>(if only I knew exactly what it was...)
>So far Hovenkamp's critique suggests to me that he really does have a good
>handle on what baseline homology is.

That's just bluffing...

P. Hovenkamp
Nationaal Herbarium Nederland - Leiden
PO Box 9514
2300 RA  Leiden
The Netherlands
hovenkamp at

More information about the Taxacom mailing list