[Taxacom] Biogeography of New Zealand

John Grehan calabar.john at gmail.com
Tue Nov 1 13:54:46 CDT 2016


Biogeography and Evolution in New Zealand

If you have any opinions at all about New Zealand biogeography and its
place in the world this is the book you cannot not to read. It is not only
the single most comprehensive book on New Zealand ever published – ever,
but it is also the only one to have comprehensively examined how
distributing patterns actually match up with tectonic and geomorphological
structures. In an age where evolutionists are continually whining with
creationists over theory vs fact they constantly overlook the one area of
evolutionary biology where there are some facts (as much as any fact may
exist).

New Zealand offers a particularly large window into evolution by the
coincidence of detailed tectonic and phylogeographic (in the broad sense)
information available for a region that is both biologically and
geologically diverse over such a small area.  I know the word ‘unique’ gets
over worn at times, but in this respect it does seem applicable. But at the
same time the lessons seen for New Zealand are globally applicable. The
extensive and precise dovetailing of biological distribution with tectonics
has been known for quite a long time, and quiet extensively documented, but
this empirical finding was cast off as meaningless by supporters of maximal
divergence theory (note a theory taking priority over observation). Now
there is a full length in depth rebuttal, not only of the maximal
divergence chimera, but of the unfounded rejection of the evolutionary
implications.

For a decade or so many researchers fell over themselves in support of the
speculation, not consistent with biogeographic evidence, that somehow
everything now in NZ crossed the oceans after the whole region reemerged
after sinking beneath the waves. Then, I hear, everyone is pleased to sink
that theory as if the decision represented progress. It’s a bit like saying
that the charge of the Light Brigade was a good idea. Of course there was
never any substance to the drowning theory in the first place.

Excerpt from p. 99 (allowing for any typos from me)

“Modern supporters of the dispersal model sometimes assert, rather than
demonstrate, that problematic aspects are “clear.” For example, McGlone
(2005) rote that “the Australasian fossil record is clearly in conflict
with a pure vicariance interpretation for many taxa,” but no examples were
cited. For the New Zealand flora, the “extraordinary evolutionary
importance of recent long-distance dispersal” is “clearly evident from
molecular data”, it is “obvious” (Winkworth et al., 19999: 1234). Waters
and Craw (2006) wrote that “molecular methods now provides a clear means of
distinguishing between recent dispersal versus ancient vicariance….even
under very rough molecular calibrations”; in fact, the dates are
problematic, and the problem of the priors means the potential error in
them is unknown (see chapter 2). McDowall (20008) argued that most of New
Zealand’s biota “clearly” arrived by dispersal following the rifting of
Zealandia from Gondwana, and he concluded that recent (postrift) dispersal
is “demonstrated” by “molecular information”. Nevertheless, molecular
information on its own does not provide the age of a group; sequence data
need to be interpreted and the phylogenies need to be calibrated.  McDowall
(2008) did not discuss the evolutionary models or the calibrations adopted
in the molecular studies, and so his assessment of the work was
unconvincing.”

John Grehan



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