Years ago, I was watching seagulls on the beach, and I noticed they would occasionally yawn. (Wikipedia backs me up on this, by the way. Birds do yawn.)
...It reminded me of all the times I've seen cats and dogs yawn.
Which got me thinking about how widespread yawning is in the animal kingdom---even though we tend to think of it as primarily a human characteristic.
I'm not a scientist, but my understanding of evolution is that this trait wouldn't be so widespread across so many species unless it serves some sort of vital function. (Scientist friends help me out--that's right, isn't it? It would have been weeded out by evolution a long time ago unless it was serving some sort of really important function, right?)
So what is the important function of yawning? According to Wikipedia, nobody really knows:
There are a number of theories that attempt to explain why humans and other animals yawn.[8][9][10] It is likely that there are a number of triggers for the behavior. However, there are comparatively few theories that attempt to explain the primary evolutionary reason for the yawn.Strange, huh?
Anyways, the past couple days I've been observing how often the newborn baby yawns, which made me think about all this stuff again.
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