The article you linked doesn’t discuss how the DR evolved, but it seems more likely to result from the occasional risk of submersion faced by most land animals, rather than something they all inherited from fish (who neither breathe nor sleep).
I’d just call that respiration. Every definition of breathing I can find is particular to lungs.
Edit: Actually, that’s not true—I found a dictionary that lists a broader metaphorical usage that encompasses all respiration (including plants and fish).
The article you linked doesn’t discuss how the DR evolved, but it seems more likely to result from the occasional risk of submersion faced by most land animals, rather than something they all inherited from fish (who neither breathe nor sleep).
Is it accurate to say fish don’t breathe? I’ve seen fish gulp at water to (presumably) push over their gills. Seems kind of like breathing to me.
I’d just call that respiration. Every definition of breathing I can find is particular to lungs.
Edit: Actually, that’s not true—I found a dictionary that lists a broader metaphorical usage that encompasses all respiration (including plants and fish).
Seems more likely than…an adaptation evolved when land animals and marine animals diverged before the distinction happened?
Ok.
https://en.wikipedia.org/wiki/Sleep_in_fish