Re: Philosophies for Character Ordering

["Jaime A. Headden" <qilongia@yahoo.com>]

Mickey Mortimer (Mickey_Mortimer111@msn.com) wrote:

<Intermediate states are of course technically their own state, but they
don't cause the intermediate taxa to clade to the exclusion of derived
taxa if the states are ordered.  I made my own test matrix to show this. 

 Tyranno    00000
 Ornithom   00011
 Confuc     11111
 Protopt    11111
 Sinornis   22222

 ...

Now, if these are all ordered, we get one tree.
(Tyranno(Ornithom(Confuc,Protopt,Sinornis))).
 The fact Confuciusornis and Protopteryx have an intermediate state
between Ornithomimus and Sinornis for characters 1-3 DOESN'T make them
form their own clade to the exclusion of Sinornis.  Just like the fact
Ornithomimus, Confuciusornis and Protopteryx have an intermediate state
between Tyrannosaurus and Sinornis doesn't make these three form their own
clade to the exclusion of Sinornis.  This is how almost everyone codes
characters.>

  Naw. Not really. *Sinornis* has a condition unique only to itself (as it
is considered transformed from the state in other birds). As stated by
myself, other features of these birds should alter this. Change half the
characters to unordered, and you get a different set of conditions, and
the phylogeny changes, as some similarities will be shaped related as well
(as Wilson stated). Suddenly, half these characters become potential
apomorphies (my point). Ordered, the characters are step-wise and will
produce this effect. As I've stated before, assumption of ordering assumes
an unknown transformation sequence (as Wilson has repeated).

<Notice how in three of these trees, Confuciusornis and Protopteryx clade
together to the exclusion of Sinornis because of their intermediate
state?>

  Yes, the state becomes synapomorphous.

<And how it can't tell Sinornis is closer to Confuciusornis and
Protopteryx than Ornithomimus is, despite the fact the birds are more
similar to each other in characters 1-3?  I have a problem with this, and
I'm sure others do too.>

  This is not a flaw of the theory, but of the lack of robusticity. No one
will be running an analysis of this brevity in taxa and characters. John
Pourtless pointed out the 9 taxon, 35 character analysis of Mayr that just
screams "NOT robust" as being why such consistency among some taxa would
be easy to support. MORE characters, MORE taxa.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


        
                
__________________________________
Do you Yahoo!?
Yahoo! Domains ? Claim yours for only $14.70/year
http://smallbusiness.promotions.yahoo.com/offer