Biogeographic memory

[John R. Grehan]

>Granted. But still not something that Turner et al can be accused of...

No, and I did not make any such accusation.



>I may have been hasty, basing my comments only on Croizat 1962 (Space,
>Time, Form: The Biological Synthesis), and possibly (excusably?) even
>overlooking some statements in those 822 pages.
>The point remains that Craw, Grehan and Heads are quite adamant that
>biogeographic analysis is not to be informed by phylogenetic analysis
>based on other characters.

Perhaps if some specific quotes were given here this could be discussed.


>This raises the question how different two distribution patterns must be
>to be distinguishable by such different means of dispersal. Given the
>choice between a butterfly and a freshwater group, would one be safe in
>venturing that a pattern ranging from New Guinea to Samoa is more likely
>to be the butterfly and a pattern restricted to Borneo more likely the
>fish? I do not ask for certainty - simply for a rational reason to make a
>choice.

One might make such assertions but that would be on the basis of other
preconceptions about the origin and evolution of particular areas. The
point about this example is that Mayr said that poor dispersing primary
freshwater fish have totally different distribution patterns from
butterflies. I emphasize the word 'totally'. The examples given were
presented as a fish and butterfly group with similar distribution ranges
with some local differences. There is no objective criterion to predict
which range is necessarily the fish or butterfly. One may claim that the
range in the Pacific is "more likely" to be a butterfly based on some
preconceived position, but that's all it would be. The same goes for the
more restricted distribution of one group than the other in the Middle
East. Means of dispersal does not provide a predicable relationship with
distribution range or pattern.


>>I believe the points raised by Hovenkamp show that Croizat's works are in
>>deed relevant to all aspects of biogeography
>That was certainly not my intention...

Sorry, but that's how the discussion seems to have developed.

>>paleocontinents. In contrast Croziat's analyses suggests the biogeography
>>is not complicated in this respect.
>
>Then it must be other respects that make Croizat's analyses appear so
>complicated ;-)

No, I was just referring to this particular respect as that was what Turner
et al were referring to.



>Quite a lot of systematic analyses pertaining to the region have been
>performed since Croizat (1968). It might be a good idea if someone would
>integrate these in a panbiogeographical framework. Preferably in less than
>400 pages...

Why less than 400 pages? Does this mean that such issues do not warrant
such pagination while other issues do?
Hovenkamp will be pleased to know, however, that steps in that
'integration' are current. A couple of examples are Heads on Abrontanella,
and Heads in press (J. Biogeography) on birds of paradise. Craw of course
has published numerous papers integrating phylogeny in general with
panbiogeography and of course the panbiogeography book does quite a lot of
this.

John Grehan

Frost Entomological Museum
Pennsylvania State University
Department of Entomology
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