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Re: Steadman's review of Mesozoic Birds



Ok, I had to jump in here"

>>>"but it is equally astonishing to see the very idea that 
the theropod hypothesis is incorrect, relegated to the realm of 
quasi-creationist pseudoscience, and with it the denigration of an entire 
discipline (ornithological systematics)."<<<

     You misunderstood what Prum said.  It is not the IDEA of non-theropod 
avian origins that isn't scientific, it is the methodology employed by 
Feduccia, Martin, et al. that borders on pseudoscience.  Evidence willing, the 
debate should continue, but not by recycling errant ideas. You cannot point out 
your favorite character that crocs (or prolacertiforms, or whatever 
non-theropod)share with birds and then ignore a much more bird-like example in 
nonavian theropods and pretend it is science (e.g. croc tooth replacement).  
You cannot claim that the pretibial bone absolutely cannot be the same as the 
ascending process of the theropod astralagus even though birds show a wide 
range of develomental origin for that condensate (including...the astralagus!) 
and pretend you are doing science.  You can't keep saying "no birds are not 
related to theropods, but we can't tell you who they are related to becasue we 
haven't found them yet" and pretend to be doing science.  And you can't c!
 la!
im that the time gap (20-40 million years depending on when the claim was made 
during the last 30 years) means that birds could not have evolved from 
dinosaurs, even though the "thecodonts" in question have a 60+ million year 
gap, and pretend you are doing science.

     You certainly can't spend 20 years publishing papers explaining how stupid 
the proponents of the theropod-bird connection are for thinking that a 
dromaeosaur looks anything like a bird ancestor, and then when feathered 
dromaeosaurs are discovered claim that all maniraptorans are birds but not 
dinosaurs and not expect at least a little flack from your collegues.

     Martin and Feduccia have made careers out of making claims long after they 
have been falsified in other papers (like croc ear and tooth replacement 
"homologies" that supposedly don't exist in dinosaurs, or claiming that double- 
shelled eggs in dinosaurs prove that birds didn't evolve from them, even though 
double-shelled eggs all come from dinosaurs that are not thought to be bird 
ancestors).  They have continued to make loud claims in the popular media 
despite making claims long since falsified.  It is simply ridiculous.  

     I have known Larry Martin for almost a decade, and he has always been nice 
to me.  I wish him all the best in life, but the charade has to stop.  This 
does not mean that there isn't a lot of zeal and animosity on the dinosaur-bird 
side, and some cladists are extremely attached to their particular cladogram.  
This personal attachement is often what drives science, but it can certainly be 
acrimonious.  It is ture that lots of good science was done before cladistics 
was invented, but that does not excuse ignoring modern techniques when 
conducting modern research.

     Finally, this does not and should not "denigrate" ornithological 
systematics.  First, many, if not most published ornithology textbooks support 
the theropod origin of birds, so it is not like ornithologists are lining up 
behind Feduccia.  Second, all modern phylogenetics is based upong the 
foundation that traditional systematics built.  Of course much of the original 
work will turn out to be somewhat wrong, and some of it will be radically 
wrong.  As we try to sort out the differences between morphological and genetic 
data, there are sure to be many more false starts waiting along the way.  None 
of that should denigrate those whose ideas are falsified becasue of new data or 
new techniques.  Ornithologists labored long and hard (and no dount with much 
care) to get us to this point, and their work is important and justified 
regardless of what details may be falsified through time.

     I guess what I'm getting at is: it's understandable to lament the excesses 
in personality sometimes seen on both sides.  And if the preponderance of the 
data had fallen in with Feduccia and Martin, some of the bird-dinosaur people 
may have fallen into similar fringe reactions.  But that does not excuse, on a 
scientific level, the belief that there is any significant debate left with the 
data at hand.  Without new (and radical) information coming to light, support 
of the non-theropod origin of birds is an excersize in futility (or worse, 
ego).  I, for one, eagerly await new fossils that could cast a light in favor 
of non-theropod avian origins.  But I also have great doubt that they exist.


Scott Hartman
Zoology & Physiology
University of Wyoming
Laramie, WY 82070

(307) 742-3799