Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!ucbvax!janus.Berkeley.EDU!bwood
From: bwood@janus.Berkeley.EDU (Blake Philip Wood)
Newsgroups: sci.bio
Subject: What distinguishes a species?
Message-ID: <33962@ucbvax.BERKELEY.EDU>
Date: 29 Jan 90 19:55:04 GMT
Sender: usenet@ucbvax.BERKELEY.EDU
Reply-To: bwood@janus.Berkeley.EDU.UUCP (Blake Philip Wood)
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Organization: University of California, Berkeley
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I'm aware that the inability to interbreed is the standard definition
of two populations being of differing species, but more precisely, 
is it:

a)  can't physically mate due to differing genitals.
b)  could, but don't mate due to differing sexual lures, rituals, etc.
c)  can mate but produce no offspring.
d)  can mate but produce sterile offspring, ie. horse+donkey=mule.

or is it several of the above?

                 Blake P. Wood - bwood@janus.Berkeley.EDU
                 Plasmas and Non-Linear Dynamics, U.C. Berkeley, EECS