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RE: Ligers and tigrons - oh my!

Quoting "Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>:

> > From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> > zone65
> >
> > What makes lions and tigers distinct species, instead of just
> > different breeds of big cat? Is this where cladistics comes in?
> >
> > Peter Markmann
> As I mentioned in some emails recently, the ability to interbreed with
> relatives is a primitive trait.  Thus, the cornerstone of the BSC
> (Biological Species Concept) is based on plesiomorphy (i.e., the lack of
> evolutionary change)!!

Very true.  And in answer to Peter's question, the apparent fact that male
offspring of a lion and tiger are invariably sterile indicates to me that they
should be retained as separate species.

Genetic studies, meanwhile, indicate that lions and tigers are not even
particularly close relatives among big cats (rather, lions are closer to
leopards and jaguars)--though I suppose if you were enough of a lumper to want
to put lions and tigers in the same species, you wouldn't bat an eye at
including leopards and jaguars as well.

Nick Pharris
Department of Linguistics
University of Michigan