[Taxacom] Biogeography of Australasia

[John Grehan]

I am fortunate to have the opportunity to begin reading Heads'
"Biogeography of Australasia" book. Regardless of one's biogeographic
perspective this book will of necessity be essential reading since it
addresses the biogeographic realities of distribution bearing on the
history and evolution of this part of the globe. I refer to 'realities'
because the spatial patterns of biological structure (in this case
principally molecular) are there for anyone to see.



So far I have only read the first chapter on the spatial component of
evolution, although the scope of this chapter alone spans more than some
entire biogeography books. Some initial quotes are:



"Biologists producing molecular phylogenies sometimes suggest that their
work has 'revealed' chance dispersal, but in a scientific study it is the
facts that everyone agrees on - not inferences and interpretations - that
are revealed."



"This approach [in the book] does not deny that chance dispersal exists,
but the focus here is on repeated patterns, not on idiosyncratic
distributions found in one or a few groups."



"The question is not so much whether dispersal or vicariance has occurred,
but whether dispersal and speciation are the result of chance movement of
individual organisms or general, underlying causes such as geological
change." [dispersalists have for decades failed to grasp this point when
saying that both dispersal and vicariance occur as if that somehow
legitimated their research program].



When I get time I will post some more. Naturally I have a bias in my
outlook, but then what biogeographer does not have a bias?



John Grehan