[Taxacom] An improved definition of cladogenesis

[Kenneth Kinman]

Hi Curtis, 
         I am saying that most species boundaries are
"initially" fuzzy (with exceptions such as  polyploids). The reason so
many of them are now sharp is that extinction has eliminated the all the
fuzzy intermediates that initially existed. So I agree with you that
many species no longer have fuzzy boundaries (thanks to extinction
trimming away the edges for us). The duck-billed platypus has very sharp
species boundaries, but it didn't start out that way, so we would need
to acknowledge that initial fuzziness when discussing its initial
divergence as a new species.          
        As for the terms cladogenesis and anagenesis, I
guess we will just have to agree to disagree.  I believe that they are
already muddy concepts no matter how you define them, and that is why
they are confusing a lot of Laura's students.  I would therefore use
these terms sparingly and with great care in order to minimize such
problems.          
         --------Ken
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Curtis wrote: 
          I guess I haven't been communicating well.
If I'm reading you correctly, you want species boundaries to be by
default fuzzy, but there are plenty that (again in retrospect) are quite
sharp. Ignore that at your peril. :-)