[Taxacom] Biogeography of Australasia

[John Grehan]

More quotes and comments. John Grehan

P. 11. "In the model adopted here, mobilism (leading to range expansion and
overlap) and immobilism (a prerequisite for vicariance) are both caused by
geology, not by chance range expansion; in others, range expansion only
takes place once or a few times in tens of millions of years...a group's
normal, ecological means of dispersal - ordinary means of survival - are
only active in range expansion during particular times in history, and
these phases of mobilism are caused by large-scale tectonic, climatic or
anthropogenic changes."

The above section helps reinforce the point that it is not simply a matter
of saying that both vicariance and dispersal occur, as if that somehow
justifies chosing between them in center of origin-dispersal biogeography.

P 12 "The fourth process, speciation by founder dispersal, is
controversial. It explains geographic distribution by chance -
extraordinary events that are proposed to happen only once in tens of
millions of years...Chance dispersal events do not correlate with any other
physical or biological factor and can explain any distribution, but they
are also difficult to investigate or test. Chance dispersal may occur, but
it has not been necessary to invoke it for any of the Australasian
distributions examined in this book."

Mike's previous book has been criticized by molecular dispersalists for
using vicariance, and yet, as is pointed out above, it is not even
necessary to invoke chance dispersal through extraordinary events. To
invert Darwin's (1859) appealing to the extraordinary is akin to appealing
to miracles.

p. 17. "...(Schweitzer et al., 2013). The authors concluded: 'our data
clearly show that the Melanesian islands Fiji, Tonga and New Caledonia
provided stepping stones for parrots in the ir colonization of the "mini
continent" New Zealand', but it was the centre of origin program, not the
data, that revealed a center of origin. In any case, the authors DID NOT
MENTION THE MAIN BREAK in the group...or provide a mechanism for it".

I inserted the upper case emphasis as this is a classic illustration of how
molecular dispersal biogeography (said to be so superior by its proponents)
consistently and constantly misses, or is blind to,  obvious biogeographic
breaks and other patterns. It's a bit like Middle Age European astronomers
failing to record a nova because the nova was not supposed to exist.
Vicariant patterns shared between taxa are not supposed to exist therefore
they do not. Wonderful how molecular dispersalists can recreate Creation
according to their Will alone.