Doing Without a Brain, or Just a Little One

My musings on this matter of the size or absence of brains began when I was confirming another fact with a retired biology teacher.  I had been wanting to make sure my description of the size of tiny coral animals was correct.  Although I had not requested the additional information, my adviser added:  "The coral are invertebrates, like sea anemones.  They have no brains."  It sounded like just the setup line for a joke by a late-night TV comedian (particularly if our elected officials had done something seemingly nonsensical earlier in the week).

Another brainless invertebrate,
a freshwater sponge

Nevertheless, my adviser on biology had simply been making the factual observation that corals, sea anemones, and other invertebrates such as sea sponges make do without a spinal cord or brain.  They do quite well without such "extras."  Sea anemones, being much larger than the nearly microscopic coral animals, are easier candidates for observation if you have a chance to watch a saltwater aquarium.  They have a mouth on top, surrounded by numerous paralyzing tentacles that detour passing food into the mouth.  The creatures, although continuously hungry, seem quite content in having no brain.  Although we humans might think that having brains is a "no brainer," evolution tells us brains are not really necessary for being a plant or even an animal.

Besides that TV-comedian joke about some people apparently not having a brain, another derisive brain-related joke is to call some person a "bird brain."  Here again, birds -- as well as many other small vertebrates -- seem quite capable of getting along with a quite small brain and skull compared to the human race.

On one occasion, I was pitted brain-to-brain against a creature of sparrow-sized brain, and I lost the competition.  My challenger had been a bat.  I was standing on a second-story balcony in the early evening, at the balcony's rail, looking out upon the open grounds before me.  In literally less than a second, a bat flew straight at my face.  Even though the whole incident happened in an instant, I was able afterward to clearly remember seeing the rapidly flying bat no more than two feet in front of my face -- and aimed right at me.  But then, the miraculous occurred:  The bat, securely guided by it's sonar system that I could not hear, instantaneously made a sharp left turn, thus preventing a collision.  I could never have been able to react that quickly.  But its tiny brain did.

We need not stop with the example of a bat's brain if we want examples of forms of intelligence packaged in a small size.  In his poem "A Considerable Speck," Robert Frost observes the behavior of a nearly microscopic "mite" (as he calls it) on a sheet of white paper on his desk. Watching the tiny animal's response to the movements of his writing pen. Frost drolly concludes:

"Plainly with an intelligence I dealt....

I have a mind myself and recognize

Mind when I meet with it in any guise

No one can know how glad I am to find

On any sheet the least display of mind."

~~~

Is there a non-human species you admire?  What species is that?  Why do you admire it?

(The excerpt from the Frost poem is taken from

"A Considerable Speck" in Complete Poems of Robert Frost, © 1967.)