Would the function of the lung be affected if the alveoli were surround by walls made of several layers of cells rather than a single layer of cells? How?
Transpiration would become less efficient, as the single layer allows oxygen to pass into the blood rapidly, extra layers would slow the absorption rate.
"...So the coach sent all the thinlungers to run a mile, while he had the thicklungers sit quietly, hoping that they didn't die from getting excited watching the runners".
:D