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I noticed that Jones has gone from saying that there is "NO evidence" for
dinosaur endothermy, to "no DIRECT evidence" (emphasis changed). An
improvement, yet a misconception that relates to an interesting statement
made by Melville while commenting on the use of statistics to analyze nasal
passage cross-sections. M said he did not like it when scientists tried to
restore the metabolic rates of dinosaurs because they cannot be directly
measured. M is expressing a common opinion. For some reason it is OK to try
to figure out how dinosaurs evolved and functioned, etc, but trying to figure
out how much energy they used is verbotten. This when we have to examine ALL
of these matters via indirect means. 

In fact, Melville's comment is dangerously close to that employeed by many
young Earth creationists. They assert an old Baconian argument that the only
legitimate science is that which can be done via direct observation and
experiment. In their view trying to tell whether evolution occurred or not is
futile because we cannot actually see what happened. Therefore, the word of
god is the only path to the truth. Of course, if this is true then much of
modern science is invalid. For example, we cannot directly measure the
energetics of the center of the sun because we cannot go there and set up
equipment. Instead we must rely on the indirect evidence of what emerges from
the surface of the sun (and photons take millions of years just to get from
the center to the photosphere). For all we know billions of sweaty guys are
shoveling coal into  furnaces in there, kept alive by a really boffo
air-conditioning system. 

Of course, indirect science is perfectly valid and often powerfully
effective. The sun really is a hydrogen fusing reactor set the center of the
solar system. Life really does evolve. Likewise, we should be able to use
indirect means to restore the thermodynamics of dinosaurs and other extinct
beasts. Melville's (probably off hand) comment is therefore not scientific,
and does not help matters. 

As for Jones and his respiratory turbinates; as valid as they may or may not
be, they are at best indirect evidence for  dinosaur energetics. Same for
ilium length, bone microstructure, limb posture, insulation and so forth.
Gathering direct evidence* will require the use of a time machine (which of
course we at the Church of Dinosaur Endothermy have already used to prove the
Inerrant Word of the Great PaleoGods that all good people must obey.) 

(* It was odd that the list of evidence needed to show that dinosaurs were
endothermic by Jones included a some direct evidence that simply cannot be
observed in dinosaurs, such as high rates of ventilation and high resting
metabolic rate.) 

Jones also stated that a large body of evidence can be refuted by one example
of direct evidence. In his case he was arguing that RT demonstrate that at
least some dinosaurs were not endothermic regardless of what other lines of
evidence may indicate. Jones is expressing a belief in the paleometabolic
"Rosetta Stone", that one character that will finally put to rest the
arguments over dinosaur energetics. It is possible that such a powerful
single character exists, but don't count on it. Animals are not sets of
disparate parts, they are complex integrated machines made of many
intermeshing parts that influence one another. There may therefore be no
single character that will show what the metabolic condition of any tetrapod
is. Instead, a large set of characters will probably have to be assesses over
a broad range of taxa.