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Re: Darwin Quote (was Paraphyly post)



>       I think you are quite right in bouncing George's challenge back to
> him.  He is certainly not alone in making such statements,
> [snip]
> And those who use Darwin to validate this
> misconception are not taking all of his statements as a whole and in
> context.

Do we really need the "argument from authority", "Darwin would have liked it
that way"?

>       I would urge George (and anyone else for that matter) to read
Darwin's
> comments on classification in Chapter 13 of The Origin of Species.  He
does
> indeed state that classifications must be genealogical in order to be
> natural (on more than one occasion).  But he immediately qualifies such
> statements in the same sentence (and here is a good example):
>       "but that the amount of difference in the several branches or
groups,
> though allied in the same degree in blood to their common progenitor, may
> differ greatly, being due to the different degrees of modification which
> they have undergone; and this is expressed by the forms being ranked under
> different genera, families, sections, or orders."  (Origins of Species,
> Chapter 13)
>      He further explains this with a paleontological example.  Taken in
full
> context, Darwin not only supports Linnean classification, but paraphyly as
> well.  I think such passages should be required reading for all
> systematists, so that they will know (as Paul Harvey might say) "the rest
of
> the story".

Of course he supported Linnean classification! There wasn't *any*
alternative!

> > >No, bacteria A and D simply >resemble< each other more than do
bacterium
> >A
> > >and Homo sapiens C. Homo sapiens C and bacterium D are, however,
equally
> > >closely >related< to ancestral bacterium A (and thus to each other).
> >
> >       Wouldn't bacteria D be even *further* removed than Homo sapiens C
> >>from common ancestral bacteria A because it had more numerous
generational
> >cycles in between?
> >       It seems to me that using using time alone to compare relatedness
> >to a common ancestor--like measuring the distance between two points on a
> >piece of paper--is inadequate in this case.

Heh heh. B-)
Good argument. I wholeheartedly agree. BTW, accepting the usual tree of
life, the last common ancestor of us and bacteria (the Last Universal Common
Ancestor, LUCA) wouldn't be called a bacterium by cladists...