[Taxacom] Chathams Re: Seed plants of Fiji

[Geoff Read]

John Grehan wrote:
> Craw (1987) gives a good illustration with respect to
> the Chatham Islands, showing how there were two entirely contradictory
> geohistorical theories and that both could be supported by the tracks
> through a different geohistorical context. 

John meant to reference Craw R 1989. Continuing the Synthesis Between 
Panbiogeography, Phylogenetic Systematics and Geology as Illustrated by 
Empirical Studies on the Biogeography of New Zealand and the Chatham 
Islands. Systematic Zoology 37(3): 291-310.

I looked through this. To me Craw's constructs seem particularly 
laboured and artificial today. Dispersal of land biota to the Chathams 
quite recently from mainland NZ is supported by this study below and 
others. The Chathams have been around a long time but the emergent 
period BP is thought to be short.

Trewick SA 2000. Molecular evidence for dispersal rather than vicariance 
as the origin of flightless insect species on the Chatham Islands, New 
Zealand. Journal of Biogeography 27(5): 1189-1200.

"Even allowing for variation in molecular evolutionary rates, these 
genetic distances indicate phylogenetic separation of New Zealand and 
Chatham insect lineages in the Pliocene (2-6 Ma). Such dates are more 
than one order of magnitude too recent to be explained by vicariant 
(tectonic) processes. Oversea dispersal from New Zealand to the Chatham 
Islands is implicated and this conclusion is in keeping with the 
taxonomy of the endemic avifauna, flora and fossil molluscan fauna."


Geoff
-- 
   Geoff Read <g.read at niwa.co.nz>
    http://www.annelida.net/
    http://www.niwascience.co.nz/ncabb/