[Taxacom] Tortoise self-rafting sea voyage

[Geoff Read]

John Grehan wrote:
> I noticed the nice propaganda statement in the link as follows:
> 
> "trans-oceanic dispersal is assumed to be the mechanism by which
> tortoises and many other animals became established on islands
> throughout the world"
> 
> It's propadanda because it implies that everyone makes this assumption.
> Of course without the assumption the floatation is no more
> biogeographically singificant than the thousands of bugs that fly to New
> Zealand every year.

That was in the abstract. Propaganda? It looked like authorial 
scene-setting. And you omitted the first word 'Although ...'.

Try this. "Rafting or drifting between isolated land masses is the only 
mechanism of dispersal open to many animals." (p2407) They probably are 
thinking of vertebrates, and note they say animals, not species.

The tortoise had a large target - Africa, and one could quibble at the 
trans-oceanic. How narrow does the gap have to be before it's no longer 
oceanic? But I guess anything off the continental shelf is an oceanic 
traverse.

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