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Re: 2 questions about characters



> after all, this is not a cladistics list,

Every few months it is one. :-) Search the archives for "cladobabble", and
you'll find just one of many such threads.

> Eh... when you say 'inapplicable codings' do you mean that the program
can't
> use the characters in the matrix  because it only recognizes 1's and 0's
and
> not things like 2's or 3's?

No, I mean that e. g. you have a character "teeth with/without serrations"
and try to code a toothless taxon.

> > > what's the good in these multistate characters?
> >
> > Well, some characters simply have more than 2 states.
>
> Yeah, but if you can turn multistate characters into 2 state characters,
> say, to avoid the inapplicable codings you mention above

To the contrary, this way inapplicable codings appear.

> let's say we use the ratio of length of the
> proximal and distal elements of the hind limbs, is it better to divide the
> measurements in several intervals (multistate) or just use 2 intervals?

This must be decided on a case-to-case basis, by looking if a discernible
number of states really exists in the material. When the ratios form a
continuum, it's often wise not to use the character at all.

> > > and is this analogous to saying "I have no idea what this means, let's
> > > use another character and let's just draw a '?' here"?
> >
> > What other character?
>
> I meant "I have no idea what this means, let's not use this particular
> character and let's draw instead a '?' here"

When you have no idea what the entire character means, you can't use it at
all (or you can simply copy it from an existing matrix, at the danger of
copying all mistakes).

To use the example with the serrated teeth from above, this would be coded ?
for a taxon in which the alveoli (holes for the tooth roots in the jawbones)
are preserved but the teeth themselves are not.