We rarely think of the biological process of respiration unceasingly going on within us because it is unseen and not consciously felt. Without it, of course, we are dead. Breathing is another matter. We do not take breathing for granted. All of us at one time or another have had trouble breathing. Perhaps you are subject to asthma attacks, or have experienced heavy smog or dust conditions. Possibly, for reasons beyond your control, you were forced to spend a little too much time underwater. Breathing is something of which we are constantly aware. Without it, the process of respiration rather quickly runs out of the oxygen so necessary to energize our metabolic system.
What happens to us when we go underwater? Click here to find out! What you are about to read is extraordinary! We do take for granted the "breathing" of fish in water, but the fact is that fish have evolved rather different mechanisms and processes for removing oxygen from water. Click here to view some of these.
What has recently been called Carrier's Constraint is an important concept in the evolution of the mammalian respiratory system. Read all about it here .
For Investigation
For each inquiry, write your thoughts in a short paragraph for later comparison.