Re: Species concepts

[zone65 <zone65@telstra.com>]

> >From: Nick Pharris <npharris@umich.edu>
> >Reply-To: npharris@umich.edu
> >To: zone65@bigpond.com
> >CC: dinosaur@usc.edu
> >Subject: Re: Of Tarbosaurs and tabbies
> >Date: Wed, 17 Mar 2004 16:41:31 -0500
> >
> >Wait, so you're advocating a system wherein any two individuals 
> who can 
> >mate to
> >produce viable (even if sterile) offspring would be lumped into 
> the same
> >species???

Nick, you must have missed my subsequent post. I contend that lions and tigers 
(and here I'll include the other big cats) are still in the process of 
diverging from their common ancestor. I therefore consider them all to be not 
the same species, nor yet *entirely* distinct species. They're transitional. 

> >I think you'd find very few specialists would agree with you 
> there.  This 
> >would
> >mean lumping entire families (Elephantidae, Equidae, Delphinidae, 
> perhaps>Felidae) into single species--

Again, 'species' is not the right word here. And perhaps some of these family 
member
s should be demoted to the genus level. 

Brad McFeeters then writes: 
> Has anyone introduced a system similar to the following?
> 
> Fertile offspring = same species
> Infertile offspring = different species of same genus
> No offspring = different genera

I would put it thus:
Fertile offspring = same species, or newly-diverging sub-species
Infertile offspring = sub-species (transitional) of recently-same species
No offspring = distinct species

Don't forget, there's a blur between the first two, what with variably fertile 
and infertile offspring resulting between lion/tiger trysts.

I am SUCH a convert to cladistics...

-Peter Markmann