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Re: Some thoughts on cladistics
> And even physicists use colors when they are not specifically talking
> about light properties. There are no wavelengthists around saying that
> nobody should ever use these color words, just because the borders are not
That's because there are no borders, and none have ever been defined. There
has never been anyone who argued about whether light of a certain wavelength
is yellow or green. There have been, and still are, incredible lots of
people who discuss whether something is a mammal or a therapsid, or a bird
or a dinosaur.
> So the question is, are groupings not based on PT/cladistics useful? Quite
> sure they are, as some examples prove:
> -There is a book called "The complete dinosaur", not containing more than
> a few words about birds,
Too few words about birds IMHO.
> - Another book (the Dinosauria) contains a chapter on prosauropods without
> being sure what exactly their status is,
So they _can't_ arrange them cladistically :-)
> and another about hypsilophodonts
> and other forms intermediate between basal ornithischians and hadrosaurs,
Chapters are some sort of ranks. Treating all basal
ornithopods/ornithischians in one chapter rather than 30 is simply easier. A
classification doesn't have chapters, unlike a book about the classified
> - this mailing list is not called "the non-avian dinosaur mailing list"
Look at all the excitement about Mesozoic birds (Details On!) and about the
gross phylogeny of Cenozoic ones on this list.
> So, although transitional forms exist and any line drawn is more or less
> arbitrary, it is nevertheless useful to draw the line somewhere.
> although they would be very much aware of
> the fact that the line is as arbitrary as the line between yellow and
Lines between colors have never been drawn.
> After all, there are still people around doing ichtyology, which
> they should not, on cladistic grounds.
Sciences are like chapters.