Re: Resending

[FlxLandry@aol.com]

Mickey wrote:

>>But IMO that  doesn't  mean old-fashioned two hundred pages long monographs 
 
>>of
>>careful anatomical  description should be  replaced by short Nature or 
>>Science
>>papers with  almost  nothing in them and some unreliable sixty taxa tree  at
>>the end.

>They haven't been.  We still get long  monographs (Clarke's on Ichthyornis, 
>Chure's upcoming on Allosaurus,  etc.), and short papers existed in the past 
>too (ever seen any original  descriptions by Marsh?).  It just takes longer 
>to write long  papers, and I for one would rather learn about a new 
discovery 
>quickly  than wait several years for a monograph.  Monographs are often  
>published for specimens originally described briefly anyway.

I  must admit that when writing my original mail and thinking of those 
wonderful  old monographs, I was briefly stricken with the "it was better 
before" 
syndrom,  which should ever be avoided, even by paleontologists. :-) But the 
fact is that,  as far as I know, not one of the recent discoveries (let's say 
the 
fuzzy ones  from Yixian) has been correctly described, and we're already 
building heaps of  trees including these taxa. Of course new discoveries should 
be 
reported as  quickly as possible, but am I really wrong when I say that short 
and superficial  descriptions are more and more frequent. Well, maybe it's 
just me, or maybe it's  because we find more new species and have too little 
time to do the job really  well. Anyway, I remember talking to Gilles Cuny when 
I 
was younger and dead  convinced that I would become a paleontologist: a VERY 
pessimistic guy about his  work, he pointed to me that NO significant 
monograph had been published in the  last 20 or 30 years (that was just before 
the 
recent bunch of them). That was a  slight exageration (what about Baryonyx and 
Massospondylus, must have I  answered), but I suppose the trend he was hinting 
at is not pure  fiction.

>>But I dare to think
>>this is NOT science. For  me,  dinosaur paleontology is mostly anatomy,
>>stratigraphy,  paleobiology and  paleoecology. The first two items are the 
>>dry  and hard
>>data on which the other  two more attractive ones are  based.
>>But where does phylogenetic systematics  fit in  there?

>Phylogenetic systematics is as much science as paleoecology  is.  

Yes, or maybe more, paleobiology and ecology being largely  based on 
speculation as soon as they intend to be precise (what I have in mind  is, for 
example, the debate about T. rex as a scavenger or not). Phylogeny  definitely 
is 
science. Crappy analyses aren't, just like bad paleobiology  isn't.

>They're 
>just determining different kinds of  facts.  You may find the higher level 
>subjects to be more  attractive, but not everyone shares your aesthetic.

Oh, I don't really  think phylogeny is less interesting than anything else 
paleo-related. When I was  younger I was fascinated by cladistics and 
phylogenies, and would have made a  reasonably good cladistic fundamentalist 
for a 
crusade against other points of  view. Now that I have studied many other 
things 
than paleontology, a little  smile tends to appear on my face when I see people 
arguing about where exactly  does some fragmentary specimen fit in the 
phylogenetic tree.

>>I  completely support
>>Nick's position in that I think we should  mostly  limit phylogenetic 
>>research
>>to the  identification of solid patterns (with or  without  postcranial
>>characters, that's not my point). But after this is done,  I  can't see the 
>>sheer
>>utility of those numerous  analyses. You add some abscure  species known 
>>from  two
>>teeth and one caudal vertebra and the tree gets  completely  changed... Get 
>>rid
>>of some characters you don't like  and  Corythosaurus might appear as a 
>>brand
>>new  ankylosaur! I'm not exagerating so  much.

>From your description  of the labile nature of current results, it should be 
>clear identifying  basic evolutionary patterns is NOT complete.

Agreed. But out of ten  analyses, how many do really contribute to a better 
knowledge of these patterns?  I feel that having a tree at the end of your 
paper is not really enough to make  a valuable contribution to phylogenetic 
knowledge.

>Most  
>published morphological cladistic analyses are crap.  Too few  characters 
and 
>taxa, too subjectively defined states.  

Yes,  that's exactly what I was saying. I love cladistic analyses, when 
they're good.  The time used to make the crappy ones could be used to better 
know 
the anatomy  of the critters they're trying to classify, no?

>Once adding a new  taxon or getting 
>rid of a few characters doesn't change topology much,  THEN you can complain 
>we should get on with other fields.

I will.  :-)

>OR I could reverse your argument.  Once we get the basics of  paleobiology 
>down, let's move on to determining low level  relationships.  We already 
know 
>Tyrannosaurus is a terrestrial  carnivore, I can't see the sheer utility in 
>all these papers trying to  determine its speed, cranial strength, binocular 
>overlap, etc..   You change some assumptions in Hutchinson's running model, 
>and come up  with completely different results. ;)

Point taken. However, even if it is  very tricky and largely based on 
speculation, if I had to chose, I would better  learn how T. rex behaved as a 
living 
animal in a living environment than whether  Daspletosaurus is more closely 
related to it or to Gorgosaurus. I don't expect  everybody to share this 
aesthetic, as you say, but I do expect not to be the  only one...

>>I keep thinking that human
>>thought is  somewhat superior to computer  calculations, and that careful,  
>>thorough
>>anatomical studies completed with  detailed  stratigraphic work can also 
>>give
>>some useful picture of  evolution. I  think we'd know more about bird 
>>origins  by
>>REALLY describing ANY of those Yixian  feathered findings  than by building
>>heaps of cladistic trees by slightly  modifying  some already used and 
>>criticised
>>matrix.

>Human  thought is inferior to PAUP when it comes to calculating most  
>parsimonious trees in a realistic time.  All the anatomical  description in 
>the world is useless for phylogenetic studies if  objective extensive 
>comparisons to other taxa aren't performed.   Madsen's monograph tells us 
>what Allosaurus' osteology was, yes.   But does it tell us how and why 
>Allosaurus is related to  Acrocanthosaurus or Carcharodontosaurus?  Okay, it 
>technically does  include a page of comparison with some other theropods, 
but 
>you get the  idea.  We need both detailed descriptions and extensive  
>phylogenetic analyses (and other studies...) to learn about the totality  of 
>an organism.

This is fine for me, but... I get the impression  than most published 
analyses are somewhat hiding behind the fact they were  calculated, by a 
computer. If 
you include a thorough description of characters used, coding methods, etc... 
and seriously discuss the results (concordance with  fossil record, and the 
like), then using PAUP is perfect. Just stuffing some  unjustified matrix into 
it and publish the result is not.

>>I  do
>>think we might figure out many things  about phylogeny if we  started 
>>thinking
>>about it instead of having  computer  programs do the work for us.
>>snip<
>>Is it  that silly to say that we  could somewhat turn back to
>>actually  thoroughly interviewing fossils instead of  comfortably use  some
>>unreliable statistical method?

>PAUP only does work we  could do ourselves if we weren't so slow.  We don't 
>use parsimony  because it's easy, we use it because it's objective.  That's 
>what  makes cladistics more scientific than non-quantitative  methodologies.

Well character definition is not that objective. Or it  would be if we had an 
absolutely complete picture of the organism including  ontogeny, individual 
variation and the like. But since we don't... Basically, as  I understand it, 
using parsimony is saying "there 51% chances that tree A is the  right one, and 
49% that it's tree B, so we'll accept tree A". Evolution acts on  the whole 
organism, not on separate parts of it; I always feel like determining  a NUMBER 
of shared characters involves a reasonable amount of cheating with  logics.

>Is morphological cladistics unreliable?   Perhaps.  I seriously doubt a lot 
>of our classic theropod  relationships are real, for instance.  But at least 
>we have a  consensus.  And I'd rather have that than unresolvable 'which  
>character is more important' debates any day.

The consensus is  useful for systematic purposes, but it could also be used 
as a hint at what we  should look for in fossils. PAUP tells tyrannosaurs are 
coelurosaurs. Okie.  Let's look again at those tyrants and redescribe them AS 
coelurosaurs, just as  we previously described them AS carnosaurs (subjective, 
yes, but important). Our  knowledge of phylogeny should, I think, come from a 
dialogue between computer  experiments and thought, not, as it sometimes does, 
only from  calculations.

>>And, more generally, is it  really  more
>>interesting to know where Torvosaurus fit on the cladistic tree  than  to 
>>know what it
>>looked like and how it  lived?

>To me, yes.  Yes it is.


Peace,

Félix  Landry