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Re: Science feather strength debate



For Jason to say that Nudds and Dyke set a high standard for scientific 
methods when every single mass and feather shaft diameter measurement they 
presented in a leading science journal was way off the mark, and they presented 
grossly inadequate documentation and other errors is an outrage. What are 
you thinking saying such a thing? Also an outrage is implying that my reply 
was scientifically inferior to their error riven paper when mine produced 
accurate measurements with documentation. The N&D paper is so flawed that it 
should be withdrawn. I have since learned that they have been developing a bad 
reputation in the field, it is they who need to reform. Really badly.

The most important reason that N&D made (yet another) major mistake in not 
citing DA is because had they done so they would have been forced to use a 
more correct body mass for the Munich Archaeopteryx they examined, rather 
than being dumb enough to use the much higher Berlin specimen mass. There is 
not a dispute concerning the mass of Archaeopteryx among those who have 
restored the species volume since three researchers have arrived at 
approximately 
the same mass for the Berlin speciems. 

The claim that I have not properly documented my mass estimates is 
offensive and ignorant. The basic technique is widely used, I been have 
presenting 
the methods for restoring body masses for decades, and I go further than most 
others in presenting multiple view restorations of many species. The 
specific gravities are listed -- not that it makes all that much difference 
because even animals "riven" with air sacs do not have SGs all that far below 
most 
land animals without them (because most animals have large lungs, their 
internal air volume is not dramatically lower than birds in which the lungs are 
much smaller - i. e. to a degree birds trade large air sac volume for 
smaller lungs -- the resulting difference in mass is only about 10-20%, not 
enough to seriously alter calculations of flight feather strength). 

The mass of the pigeon cited in the reply is that of a live animal of the 
size figured, so there is no need to estimate its air sac volume. 

My skeletal restoration volumetric Munich specimen mass was published as 
the Science reply clearly cites years ago in DA. It is not based as Jason 
seems to imagine on some  comparison with pigeons (the figure in my reply is 
intended to visually show readers of Science that the Munich specimen is much 
smaller than a pigeon). 

In his fantasy world Jason imagines that for some reason I must and can 
reply to N&Ds hyperdefective paper only by "recruiting "a team of eager young 
biologists and engineers to build aerodynamic models" to test their methods. 
Jason who works at a large budget museum is detached from reality for those 
who do not have access to such resources. How the hell I am, an independent 
researcher with no budget (it's not like I can get a grant from the NSF -- 
or David Koch) I can supposed to do that? Here, Jason, is how it works in the 
real world I live in. I come across a paper that (as the reviewers of my 
reply noted should not have gotten past peer review) has one glaring defect 
after another. It is begging for a rebuttal, and it was well within my 
capacity time, budget and skill capacity to write up and publish the badly 
needed 
reply that points out the obvious defects so the scientific community can 
take them into account. That is all I need to do -- it's standard scientific 
procedure to produce short rebuttals limited to specific errors (that's what 
Technical Comments is for), Jason seems to think that a rebuttal must be a 
large comprehensive study. Others are now free if they wish to try and further 
develop methods for examining wing feather strength with they resources 
they have available (but not for Archaeopteryx because the needed data is not 
present in the fossils), and with my data promplty published in the 
literature available for further work. That too is how science works.  

GSPaul




In a message dated 10/27/10 11:50:35 AM, jaseb@amnh.org writes:

<< In your recent posts about the Nudds and Dyke Paper you have called 
their conclusions silly.  I wholeheartedly agree with you that they should have 
presented good figures for proximal rachises along with their conclusions 
and that this missing data weakens the paper. But on other points I fear you 
have seemed dismissive.

Correct or not, Nudds and Dyke have provided an explicit and empirical 
methodology and their conclusions can be supported or falsified on their own 
terms. In accomplishing this they have set a  high standard for scientific 
methods.

I would suggest that their method calls for a response in kind, and that 
you should recruit a team of eager young biologists and engineers to build 
aerodynamic models to test, for example, whether the overlapping feather vanes 
of Confuciusornis would strengthen the wing enough to prevent buckling.

You are free to analyze whether the proportionately long arms and short 
legs of Confuciusornis correlate in a statistically significant way with flying 
animals and do not overlap with non - flying animals.

You are also free to analyze whether there is a statistically significant 
correlation between flight abilities and the formation of abundant  
lacustrine fossils.

All of these are scientifically valid responses, but I don't feel that 
categorical dismissals are.

You wrote that you were irritated that Nudds and Dyke (and "lots of folks") 
did not cite Dinosaurs of the Air. Speaking for myself, I feel that your 
book could have been far more persuasive and influential if its methods had 
been explicit and if it had proposed methods by which your hypotheses could be 
falsified.

For example, I could not find the calculations that you used to estimate 
body mass for Archaeopteryx in either DA or Predatory Dinosaurs of the World. 
In the former you do mention Yalden's calculations, but then you state that 
his estimate is too high and you lower it without providing any mathematical 
reason for doing so. In your technical comment on Nudds and Dyke you show 
two elevation drawings: silhouettes of a pigeon and of Confuciusornis, as 
your only evidence that the pigeon weighs more. But a pigeon is a three - 
dimensional object, and riven with pneumatic air sacs. If the pigeon was more 
voluminous you did not calculate this, and you provide no evidence as to 
whether the pigeon is more or less dense than a more basal bird. Then you go on 
to 
say that the lower mass of the Munich Archaeopteryx makes the feathers 
"several times stronger" when you must have meant that they have several times 
less loading. But my point is that you are less persuasive when you simply 
write that this is so than you would be if you provided calculations that can 
be checked by your readers.

If we hypothesize that Confuciusornis was capable of powered flight, this 
hypothesis must be falsifiable in order to be scientifically valid, correct? 
So perhaps one day  an overwhelming body of evidence will demonstrates that 
it was a littoral scavenger that roosted in trees overhanging lakes, and 
parachuted down to the shoreline to forage. You and I think that this is highly 
unlikely, but that doesn't matter.  What matters is that we design 
experiments rigorously so that their results will be believable. >>

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