[Taxacom] Polar bears as subspecies or species

Frederick W Schueler bckcdb at istar.ca
Fri Jan 23 09:13:31 CST 2009


Kenneth Kinman wrote:
> 
> I would agree that "laboratory" hybridization experiments are
> suspect (often not reflecting what actually occurs in nature).  However,
> I found that there are certainly some good examples of a "ring of
> subspecies" (a.k.a. Rassenkreis...

* I don't have any problem with Rassenkreis, I was just spooked by the 
possibility that Moore's well-meaning but geographically and 
systematically naive conclusions, about the Leopard Frogs that he lumped 
into "Rana pipiens," might be the basis for John's memory. It was 1978 
when I cut a discussion of Moore's conclusions from my thesis as an 
unnecessary repetition of points repeatedly made elsewhere.

But the polytypic species was the hot item in those days, just as the 
phylogenetic species is in these, and it was the procrustean bed with 
which Moore was working. It wasn't a Rassenkreise, in any event, just 
increased hybrid inviability with increased latitudinal distance, across 
what are now (i.e. post mid-1960s) recognized as species boundaries.

> I think much of this has been in recent decades fed in part by
> strict cladists' knee-jerk reactions to any suggestion that a species
> might be paraphyletic, resulting in the splitting of the paraphyletic
> mother species (although some of them take the alternate route of
> overlumping the mother species with any daughter species). 

* poor Truth, her relationship with Procrustes has always been so abusive...

fred.
============================================
> 
> ****************************************************
> Fred wrote:
>       I fear that this may be a memory of Moore's studies of laboratory
> hybridization of Leopard Frogs in the 1940's. In the 1960's these
> populations were shown to be divided into several perfectly good species
> (though with grizzly x polar bear-like levels of hybridization among
> some peripatric species pairs).
> _______________________________________________
> 

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