[Taxacom] Usefulness vs. convenience (Protista)

[Kleo Pullin]

--- On Sun, 12/19/10, Stephen Thorpe <stephen_thorpe at yahoo.co.nz> wrote:

>>Do non-cladists give only stable and conclusive results?
>Didn't say that they did, but highest level molecular phylogenetics of life 
seems particularly unstable and inconclusive ...

Can you give an specific example of an unstable and inconclusive higher level taxon? (More than one, if it's an older or brand new C-S?)

Are they just inconclusive when they show we know less than we thought we knew? Without a specific example, I'm not sure what's being discussed. I'd like to be able to examine it and see what is going on that leads to this statement.



>I expect paraphyletic groups like Protista are useful to bioinformaticians who 
don't want to have to change their higher classification every time someone 
publishes a new phylogeny ...


But if their higher level classification is wrong to begin with it is. But, again, do you have an example for this that I could look at?

Thanks, 

Kleo

________________________________
From: Kleo Pullin <kleopullin at pacbell.net>

Do non-cladists give only stable and conclusive results? 

And conclusive in what manner? If new molecular information, or if a new means 
of examining physical information, changes how Linneaus classified an organism, 
the Linnean taxonomy changes. Doesn't this show that the results were not 
conclusive because some data were missing to begin with? So, how are taxonomic 
relationships conclusive when they show a relationship that is based on a 
non-cladistic relationship? An example would help me out.

For the trees, I see how a finite geographic area makes only the descriptions of 
the species, without their evolutionary relationships useful. On the other hand, 
as soon as you expand your geographic area or your time span, isn't it useful to 
know about closely related species, as in genetically related? Because, after 
all, isn't this where you will expand your knowledge of species through space 
and time, by looking at close genetic relationships?

I can see how Protista is useful; but I was hoping some of you could tell me 
other ways in which it is useful to you. It's useful for me when trying to 
explain eukaryotic micro-organisms to children, particularly amoeba and 
photosynthetic (and sometimes not) single-celled organisms that are not plants, 
animals or fungi. Very helpful as a starting point to have this dump-all 
category. 


But, I would like more information from taxonomists on this list about how they 
find using a group such as "Protista" useful in their work. 


Also, anyone know who is classifying Rhodophyta as other than plants these days?

Again, thanks for the response.

Kleo

--- On Sun, 12/19/10, Stephen Thorpe <stephen_thorpe at yahoo.co.nz> wrote:


>From: Stephen Thorpe <stephen_thorpe at yahoo.co.nz>
>Date: Sunday, December 19, 2010, 11:57 AM
>
>
>>but I am struck by the usefulness of this discussion
>is that usefulness or convenience?
>
>>1) classifications are most valuable when they reflect our knowledge of 
>>evolutionary history 
>>
>> Why are we attempting to classify life in the 21st century without including 
>>our understanding of the "tree of life"?
>
>if cladistics gave stable and conclusive results, then all would be well, but it 
>ain't so ...
>
>there is no a priori reason why classification needs to follow phylogenetics ... 
>phylogeneticists can study phlogeny and leave it to taxonomists to do 
>classification ...
>
>Stephe
>
>
>
>