Re: Sclerotic rings

[Mickey Rowe <rowe@psych.ucsb.edu>]

On ossicles, "Gordon Martin Human" <t_gmhuman@agency.com> writes:

> Turtles and tuna? Doesn't this (deformation due to pressure) seem
> rather contradictory as an explanation for ossicles, then?

Please don't fall into the trap of thinking that the ossicles must
perform the same function even within groups for which the ossicles
might be homologs of each other.  Turtle lungs and fish swim bladders
are more definitely homologs of each other than turtle ossicles are to
fish ossicles, but although many fish use their bladders for gas
exchange and many turtles use their lungs to adjust buoyancy, I don't
think people would generally ascribe the same function to the organs
in the two different lineages.

-- 
Mickey Rowe     (rowe@psych.ucsb.edu)