Sunday, January 25, 2009

An irreductionist looks at yeast

This is science:
Yeast have over 6,000 genes. More than half of these genes resemble human genes.

This is technology:
Some mutant yeast genes can be replaced by human genes with similar function. The yeast cell then acts normal again.

This is what happens in my kitchen:
I add a few billion yeast to flour, water, honey, water, olive oil, and salt. They play like mad, reproducing, blowing off carbon dioxide. I then slaughter them in the oven.

I add a few billion yeast to water, malted barley, and hops. They play like mad, reproducing, blowing off carbon dioxide. I put an air lock on brew bucket. My yeast use up the oxygen, switch to alcoholic fermentation, poison themselves with ethanol, and go dormant.

Science is about what we can know through direct or indirect observation; it requires a reductionist view of the universe. (Well, OK, the physicists are busy studying God, but for the rest of us....)

Science is a very powerful tool, and what we do with our knowledge (technology), has warped our world in ways we could not have anticipated.

If we teach reductionist thinking as the way to think, as we do in science class, we lose too much.


I have no idea what it feels like to be a yeast cell, and I have no scientific way to figure it out. I know they do not have legs, or eyes, or teeth, or brains, so I can safely presume that their existence hardly matches my own. While scientists play with the yeast genome (fully mapped out in 1996), comparing and contrasting their nucleotide sequences with our own, they have no interest in what it means to be a yeast.

Oh, a chemist may well wax philosophic on her yeasties as she bottles her finest homemade cherry stout, but she's not going to pretend that anything scientific will result from her musings.

I am nutty enough to rinse out the yellow Munton ale yeast package so that the few remaining thousands (millions?) can be released in my backyard. This is madness in a reductionist universe, but offers comfort to my irrational side.

(What word does a public school science teacher dare use for "irrational"? Superstitious? Mystical? Crazy? Traditional? Cultural? Religious?)

In science class, I am careful about wandering into the irrational world. I do have an imaginary leprechaun wandering around Room B258--he serves to remind us of what defines the "natural" world--but I am not going to launch into some existentialist babbling about yeast in my classroom.

I do, however, make a point about the distinction--when we wander to the edge of reductionist knowledge, I will tell the class that some things are unanswerable by science.

How do you handle the questions that take you to the edge of rational knowledge?


Dreamy turtule said...

Hello high school teacher!
After scrolling through many blogs i found ur blogs very interesting, specially ur yeast story;)
And from now i will keep following ur blogs;)
Have a nice day

Kate Tabor said...

This was the essence of a conversation between two students in Journalism class when the large hadron collider was turned on and we were (apparently) not sucked into a black hole:
"But how do you know we weren't?"
"arrggh- don't make me think about that..."

I have my own invisible leprechaun.

doyle said...

Hi, Dreamy

Glad you like it. I hope you like clams--once the water warms up, I babble on and on about my shelled critters.

Hi, Kate

I love conversations like that in class, especially if a kid grabs his head and says "Stop! My brain hurts thinking about that!"

Do you talk about your leprechaun in class?