Thursday, August 7, 2008

Big Ideas: "One Living Filament"


Organic life beneath the shoreless waves
Was born and nurs'd in ocean's pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.

Erasmus Darwin. The Temple of Nature. 1802.

Charles Darwin thoughts descended with modification from his grandfather, Erasmus Darwin, a brilliant thinker with a nutty (but entertaining) edginess.

Erasmus believed E conchis omnia ("everything from shellfish") strongly enough to write it on his carriage, perhaps the first man to plaster the evolution "debate" on his vehicle.

(Putting a Darwin fish on your car's bumper is not quite the same thing--co-opting the ichthys symbol hardly advances scientific thought, and given the ichthys' history, I can understand why folks might be upset by it.)

I plan to infuse the concept of "Big Idea" throughout my lessons this year--no sense pounding away at the minutiae if come June my students still believe we descended from chimpanzees, that water is alive, and plants are not.


Today's big idea:
Everything alive here on Earth today is just as "evolved" as everything else alive. Humans are remarkably adapted to the environment,
but so are earthworms, horseshoe crabs, petunias, and jelly fish. Each organism alive is the new, shiny latest model, all part of "one living filament."


But Mr. Dr. Doyle, we're more evolved than earthworms!

I'd love to toss the word "evolution", but it's the language we use, so I'm stuck. And we tell ourselves how special we are (and I agree we are), but miss the larger point of how special all life is (though to even entertain such thoughts aloud in a public classroom borders on "school sponsorship of a religious message").

So Mr. Dr. Doyle, you mean to tell me that earthworm is as intelligent as me?
No, not at all--just that the earthworm has been evolving every bit as long as you have, and that at some point you have a common ancestor.

You mean earthworms evolved from chimpanzees, too?
Um, no...

The concept of descent with modification forms the backbone of biology today--if I can get the concept across early, say by October, with a class full of 14 year old skeptics (a good thing), then maybe by February, when DNA gets tossed around a bit, a few of my kids will have the "Aha!" moments that make teaching (indeed, life) worthwhile.


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