[Taxacom] Seed plants of Fiji

[Karl Magnacca]

On Wed, November 15, 2006 2:36 pm, John Grehan wrote:
> What is the Lemuria remark supposed to mean? Does it mean that you have
> already decided the answer to the Pacific that does not allow for a
> vicariant origin?

Well, you have an isolated hot-spot* island chain, with slopes that go
straight to the abyssal plain.  Even where there are undersea connections
between islands, aside from Maui Nui and Oahu they are thousands of feet
deep.  A check of the seafloor shows no major features for almost 2000
miles around, except for some rifts on the seafloor a few hundred miles
southwest of Gardner.  All the islands are more or less circular, modified
by volcanic rifting, with no faulting that would indicate separation from
another, missing land mass.

* - there is some dispute about the standard hot-spot model, but AFAIK the
alternatives don't mention connection to other land masses.

So to answer your question - yes, I have already decided that my
conception of the Pacific does not allow for a vicariant origin of the
Hawaiian biota.  Not from jumping to conclusions based on preconceptions,
but because there is no evidence at all that the Hawaiian Islands have
been anything other than always isolated.

If you want to argue about the Fijian biota being vicariant, I might buy
that.  But for anything east of Tonga, you're stretching credibility.

Karl