Is biogeography science?

P.Hovenkamp Hovenkamp at NHN.LEIDENUNIV.NL
Fri Apr 26 10:30:16 CDT 2002

At 08:07 AM 4/25/02 -0400, John Grehan wrote:
>Peter Hovenkamp wrote:
>>Coming back to the original question:
>>>>So if I try to explain the currently pantropical
>>>>distribution of, say, Nephrolepis multiflora to the best of my ability and
>>>>on basis of the currently accepted knowledge, I am participating in a
>>>>metaphysical research program?
>>According to John Grehan, then, this is not "informative" science. If it is
>>not informative, it tells us nothing new. If it does not tell us anything
>>new, we must already know the answer. What is it, then? By which process
>>did the species attain its current distribution?
>If I used the words 'nothing new' then I could have added to confusion. My
>is that in using other sciences to provide historical information to
>interpret the distribution
>one is precluding biogeography itself from providing any information about
>the history
>of the distribution.

But in this case, I don't care where the information is coming from. I just
want the best. So I'm not precluding anything. If biogeography offers a
convincing pattern that I can correlate this species distribution to, OK.
But that pattern may need to be interpreted with the help of the best of
current geological results - that's OK too. In the absence of
biogeographical data shedding any light on my problem, I may have to do
with geological data only. No problem. All I want is to know what scenario
is, on basis of the best of current knowledge, the best available
explanation for something I've observed. I realize that even the best
scenario may still be wrong - if any of the data on which it is based turn
out to be wrong -but that's science. If you want to be right always, better
not say anything at all.

>One is reduced to just mapping distributions and
>constructing phylogenies,
>but looking to other sciences (actually looking for historical narratives
>generated by other
>sciences) to give historical meaning to the distribution. Even when one
>does a cladogram and
>constructs some sort of hierarchical cladogram of area relationships, one
>is still just left with
>a hierarchical classification that of itself does not appear to generate
>historical predictions
>independently of other disciplines, but rather is interpreted for its match
>against other historical
>narratives (such as splitting events from geology or paleoclimatology

One of the things a hierarchical scheme does is to specify a relative order
of the splitting events   - something a panbiogeographical analysis, as far
as I can see, will never do. It is not too dificult to see this
specification of relative temporal order a "historical prediction".

>>Is any science uninformative that uses results from other branches of
>If it is restricted to this activity it seems to me that the answer is yes.
>Perhaps others
>more acquainted with the philosophy of science could comment.
>John Grehan

The restriction is new here, and was not present in the original statement
which caught my attention - let's have it again:

quote from John Grehan:
center of origin/dispersalist approaches are a collection of metaphysical
research programs that aim to provide explanation in the light of currently
accepted knowledge rather than prediction beyond or counter to such knowledge.

Note that this statement uses the much laxer "in the light of" - suggesting
that any approach that even dares look to other sciences is itself not

I'm glad that that, at least, seems not to have been John Grehan's intention.

Peter Hovenkamp

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