[Taxacom] Dispersal paradigm (was: Antarctic dispersal)

[Richard Pyle]

Hi Michael,

> You wrote: 'That you can find examples where ecologically 
> disparate organisms fall into repeated patterns of distribution 
> across many different taxonomic groups is not at all surprising 
> to me, because I do not reject vicariance as a mechanism of 
> speciation...'
>
> I agree with this, although Ken doesn't - he believes the 
> molecular clock dates and so thinks the geographic patterns 
> are 'pseudopatterns' caused by chance, not vicariance. 

I won't speak for Ken, but I have not seen him reject vicariance.  I have seen him (usually with good and compelling reason) cast doubt on specific cases purported to represent support of vicariance as a contributing mechanism to speciation.  I am not familiar enough with the facts in those cases to know whether to agree with him or not.  And, if this debate is about specific individual cases fitting a pattern or not -- then I think that is very much a legitimate debate to have.  But that doesn't strike me as the main theme running through this ongoing dialog.

Aloha,
Rich