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a little background



Hi again,
        Sorry about the long post previously; I hope people are not responding by attaching the whole text without cutting+pasting.  Here is another long post.  Don't worry, I will shut up soon enough.  :)

        Some history behind our research might help people understand where we're coming from with this study.  If my tone here sounds defensive, it's because I am grouchy from lack of sleep, overcaffeination, endless phonecalls, and annoying e-mails from yahoos who tell me that gravity was much lower in the Mesozoic era, so I am wrong.  [I'm no astronomer or geophysicist, but as far as I know "g" was still close to 9.81 m/s^2;  only 65 mya...... if anyone knows of published papers that discuss this I'd love to hear more]  Believe me, the dinolist is a breath of fresh air compared to the creationists and pseudoscientists who have now started to flood my mailbox.  I can't wait to see what the Enquirer does with this... shiver.  Anyway, I am trying to be honest and forthcoming in this e-mail to dispell any illusions about our research, which has become overhyped and misinterpreted despite our best intentions and efforts (shit happens).

        I am not at all ashamed to admit that I was inspired in the 1990s by reading a copy of Gregory S Paul's book Predatory Dinosaurs of the World.  It really brought dinosaurs to life for me, and I loved it.  Ditto for Jurassic Park when I saw it later.  Both experiences convinced me that I wanted to study dinosaur biomechanics in grad school.  I think I might have even asked Greg if he was accepting grad students!  At a biology conference I ran into Bob Full, who studies cockroach and other animal biomechanics.  I was applying to Berkeley to work with Padian, and told Bob that I'd love to build some tyrannosaur models like he and his students did for insects.  He jumped and said, "We've been looking for a student to do that for years!"  And so I spent 6 yrs at Cal doing that.  Now Ive spent almost 7 years on the dinolist, often quite vocal, especially in my impetuous early days.  I am no stranger to dinosaur science.

        Anyway, I always found Greg and others' arguments about fast tyrannosaurs very interesting, and at times convincing.  Greg has made the best (by far) arguments for fast-running tyrannosaurs, ever.  Bakker barely scratched the surface and I didn't read Dinosaur Heresies until much later.  No one else has done anything that convinces me; Greg's work is the only one with much substance to it.  He has published work in peer-reviewed journals and his opinions deserve respect; he's been very observant as many professional paleontologists have noted before.  I mean him no personal insult by disagreeing with him.  This is just science and I try to keep it that way.  He or someone else might prove me wrong, and I could live with that.

        Where Greg's research and our research disagrees is on the use of anatomy to estimate locomotor performance.  We both agree that anatomy is extremely important, and I consider myself to be an anatomist first and foremost (hence the slew of long papers about it, which led up to this study, and subsequent papers with Carrano and others soon).  As a biomechanist, I know that in order to move at a certain speed or execute any other activity, an animal must exert a certain amount of force, and that force scales more slowly than body mass does.  That's what led me to doubt Greg's and others' arguments, and we explain our logic in the paper quite clearly I hope.  Our website goes into some more detail, and I encourage people to read up on work by Biewener, Alexander, and many others.  The methods and evidence we use are standards in the field and hold up well to experimental analysis.  Given the amount of unknowns for tyrannosaurs, we still might be wrong, but we have done our honest best with what the fossil record and living realm provide.

        After ~4 yrs in grad school of dissecting animals, studying fossils, and working on live animals a bit, I felt like I'd learned enough about tyrannosaur anatomy to do some simple models of tyrannosaur biomechanics.  I asked Mariano Garcia, a postdoc in Bob's lab, to help me with the computer stuff, and we were pretty sure we could get a paper out of it.  Two years later, I finished my thesis and we submitted the paper to Science.  Rejected without review; "interesting but too specialized"   (i.e., too much math? or just boring).  Fine, over to Nature then.  Two anonymous reviewers who seemed to know their dinosaurs and biomechanics quite well gave favorable reviews, so it was published after some revisions and added analyses at Stanford.  Here, I now am learning more biomechanics skills from people who study humans, and use models to show how humans work.  The models work for humans, by the way, and frogs and cockroaches, etc.  Physics transcends the essentialism of taxonomy as long as the biology is reasonably captured along with the physics.

        Now we're caught up.  I hope people understand that this was not some project that Mariano and I sketched on a napkin after a few beers last week, and decided to publish as an assault on paleontology, and then abandon to let paleontologists pick up the pieces.  This was a lot of work and we are serious about it, and I will continue pursuing these sorts of scientific questions for the rest of my career.  I welcome disagreement with our work as long as it is scientific and not superficial.  I expect SVP next year will have at least one talk criticizing our research, and I'm sorry that I won't be there this year (first time in 6 yrs!) to respond.  We'll work things out in the scientific peer review process over the next few years, I hope.

        Back to work for me.  Take care, everyone.

John


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John R Hutchinson
NSF Postdoctoral Research Fellow
Biomechanical Engineering Division
Stanford University
Durand 209, BME
Stanford, CA 94305-4038
(650) 736-0804 lab
(415) 871-6437 cell
(650) 725-1587 fax
http://tam.cornell.edu/students/garcia/.trex_www/naturepaper.html
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