rw wrote in message ...
On 2004-02-06 15:21:48 -0700, (Jonathan Cook) said:

Lions and tigers have been bred and produced fertile offspring. Would you
call them one species?

Assuming fertile offspring is the norm between the two, yes.

If biologists were consistent in applying their own "rules" about
what constitutes a species, such as physical, geographic, or
behavioral isolation, then we ought to have a multitude of human
species, and a multitude of dog species, and plenty of other
examples. The current use of these rules is "soft science" and
it bothers me.

Lately it seems like the readiness to declare new species is also
founded on political reasons -- mainly to bring the endangered
species act into play and "preserve" the environment. In NM we have
the Rio Grande silvery minnow, a very endangered species. Well we
had a state biologist talk at our FF club and I learned that there's
a Pecos river silvery minnow that is not endangered and that can
only be distinguished from the RG minnow by a delicate autopsy
and inspection of the vertabrae at the base of the skull. When I
asked why it is considered a different species, I was basically
talked down to as if I didn't understand science and no
reasonable person would even think that (they *are* geographically
isolated and have been for a while).

Jon.