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Re: New refs (long)



From: <DinoBoyGraphics@aol.com>

>>>      There is a final falacy that Seebacher's paper falls for;  The
supposed importance of body temperature.  High (and more importantly,
constant) body temperatures are advantageous to enzymatic processes, as well
as a host of other metabolic pathways.  But without an elevated RMR, your
body can't take advantage of it.<<<

So how do you explain the relationship between oxygen consumption and core
body temperature at rest? And the relationship with long-term growth rate?
And on a related note, what about the phenomenon of metabolic depression in
chelonia and (possibly) crocodylia at stable core body temperatures during
estivation?


>>> In the wild, the inability of ectotherms to thermoregulate as
effectively, and the inabiliy to gather enough food (due to lower aerobic
excersize capabilities) prevents them from enjoying most of the benefits of
a higher body temperature.<<<

What benefits are those? Higher energy requirements? No croc could ever be
an endotherm without significantly altering its behavioural ecology.


>>>     This is confirmed by growth series of Deinosuchus.  Undoubtadely at
some point in their growth the large crocs must have aquired
"gigantothermic" fairly constant body temperature.  Despite this, they never
show the fast growth rate (i.e. fibrolemellar bone deposition) that all
dinosaurs show, regardeless of size.<<<

While that might be true, croc growth rates are influenced by a greater
number of variables than just core body temperature. Thermal stability can
actually be detrimental to growth rates in ectotherms - crocs for example
often select lower core body temperatures when food is not available, yet
this is further influenced by social and environmental factors (life is not
perfect).

Adam