[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

RE: Philosophies for Character Ordering




Jaime A. Headden wrote:

 >>As Mickey pointed out correctly, "ordering" argues that a taxon with
condition "2" must have "1" as well as "0", which is how it's treated in
the machine, and infers that the condition is progressive and in that
form, rather than in any other combination of acquisition or gradual loss.<<

I'm not sure of the definition of "correctly" here. I do not believe it is
consistent with the theoretical basis of cladistic systematics to have
states in a character that are not independent from one another and mutually
exclusive. If an organism can be in both states 0 and 2, then the character
is ill-defined.

>>A taxon that makes a "jump" from "0" to "2" is inferred to have gone
through stage "1" in its evolution (I made this point by bringing up where
a taxon can incorporate two vertebrae into the sacrum simultaneously
rather than one by one; the machine will interpret this the same way).<<

The machine appears to be making alot of assumptions here. Why not make the
characters dependent on one another, if one is willing to allow the states
to be dependent. For example, write a character that says if Character A is
in state 0 and Character B is in state 1 then Character C is in state 0,
otherwise state 1. If the states of Characters A and B map uniquely to the
states in Character C, you can discard A and B without loss of information.

>>This is an intrinsic assumption of an unobserved process of evolution, and
appears to occur only through corrolary, and that can be done without
ordering any characters.<<

Can you please state the intrinsic assumption and associated corollary, if
an assumption can have a corollary.

Regards,

Mike Milbocker