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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should be withdrawn.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
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
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
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
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.
In a message dated 10/27/10 11:50:35 AM, email@example.com 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
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
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
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
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. >>