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Re: Function Talks at Ostrom Symposium

In a message dated 2/20/99 1:32:53 AM Eastern Standard Time,
Dwight.Stewart@VLSI.com writes:

1) >    How certain is it that dinosaurs WERE diaphragm breathers?  And
2) >  why would the transition
>       forms (IF dinosaurs were diaphragm breathers) be selected for a
>  diaphragmatic hernia?
>       Dwight

Hi Dwight, thanks for replying.
1) Dinosaurs as diaphragm breathers is discussed in the 1/22 Science on p.

2) What Ruben et al. meant is since birds are not diaphragm breathers a
diaphragm breathing ancestor for birds would have to rupture its diaphragm to
gradually eliminate it and breath without one. However, you try breathing with
a ruptured diaphragm! Such a debilitating condition would immediately
compromise the entire pulmonary ventilatory apparatus and seems unlikely to
have been of any selective advantage.

Hope that helps,

FMI: http://ucs.orst.edu/~joneste/rubenlab.htm