Evolution

[iffr762 at utxvms.cc.utexas.edu]

	I guess I had better compose a response to Steve Long ... ugh, I
would rather not.   That will teach me to start something I don't feel
like finishing.

	Mutations occur within an overall system, within which they are
effectively meaningful. Those that failed this test would not be
considered mutations.  (Say if the copying process had for some bizarre
reason produced not a nucleotide, but H2O.)  Thus rhetorical courtesy
requires that the proposed parallel with language be similarly constrained
to include only innovations that occur within the system of the language
in question.  The sort of random noise-making that Steve Long suggests is
implied by my parallel does not qualify, any more than H2O qualifies as a
nucleotide.

	Moving right along, and attempting to end a conversation which
most members probably consider annoying/boring, I suggest that the main
difference between linguistic evolution and biological evolution is that
virtually every aspect of an individual organism has a functional purpose,
such that it cannot be other than it is, whereas many aspects of language
have no functional purpose.  By this I mean there is no reason that we
must call cats "cats" and dogs "dogs".  Indeed, without this little bit of
leverage, we historical linguists would be in big trouble trying to do
what we do.

	Evolutionary biologists do, by the way, have a great deal of
trouble trying to do what they do without this leverage.  Since virtually
every aspect of a skeleton has a function, sorting out convergence from
common descent can indeed be tricky business.  For example, a group of
very cat-like carnivores, the nimravids, were considered cats until
somebody noticed that the structure of the middle ear (fairly marginal for
predators, compared to teeth and claws, etc.) was significantly different.
The striking resemblance between nimravids and felines was thereupon
declared due to convergence.

	There is more, as always, but I am hoping I will not have to write
more on this.

					DLW