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Re: Birds and pornography



On Fri, Feb 01, 2002 at 12:33:10AM +0000, Ken Kinman sent:
> And if so, it is just one more reason that these closer coelurosaurs
> should be classified as birds.  The cladistic definition may
> eventually *force* cladists to include maniraptors in Aves!!  The
> closer the eclectic Aves (apomorphy-based) and cladistic Aves end up
> in content, the better off we will all be once the dust has settled.
> Anyway, I am really looking forward to Greg Paul's book.

You know the folks who don't care to eat vegetables, and classify fish
as water-dwelling vegetables with scales?

That's what this argument reminds me of.

The useful thing about phylogenetic systematics is that it isn't trying
to nail the jello to a tree; it's inherently tied to the present state
of knowledge.

The kind of stability you're talking about is the stability of something
known to be constant, while the fundamental character of evolution is
_change_.

Somewhere way back there, is a thing which dwelt in the sea; all that
lives and has a spine is descended from it.

Unless, of course, tomorrow someone finds clear proof that spines have
evolved more than once.

There just isn't any way around that difficulty; our knowledge of the
history of life is necessarily fragmentary, and the the mechanism of
natural selection, the thing we _are_ sure of, guarantees that there
aren't going to be any clear divisions between closely related
organisms.  Linnean systems *can't handle close relationships*.  To be
of any use to an evolutionary biologist or a paleontologist, a
classification system *must* handle close relationships.

-- 
graydon@dsl.ca   |  Hige sceal þe heardra, heorte þe cenre,
                 |  mod sceal þe mare þe ure maegen lytlað.
                 |   -- Beorhtwold, "The Battle of Maldon"