Day Two – ‘Just because you can do something… doesn’t mean you should’

24 Aug

“I guess I should have seen this coming.”

A simple quote from Jeff Goldblum’s character in Jurassic Park.

This became relevant in my second day’s biology class, but not until after we reviewed all of my frantic ramblings from day one. I reviewed what science is… A systematic way of asking questions where you assume little or nothing. Science first became systematized with Descarte’s ‘Discourse on Method’. This marked the turning point in science from an exercise in asking questions idly and contemplating the answers without experimentation, to a real discipline where data was king.

The first question I posed as a thought experiment and walkthrough of history was: “Where does life come from?”

It’s difficult for a 20th century mind to ask this question as it was being asking in the 17th through 19th centuries. Aristotle had been certain, “Life comes from non-living matter. Just look at the dead animal in the forest, after a day the maggots have developed from the decaying material. Then flies. Then larger animals.” This was the theory of Aristotelian abiogenesis.

In my mind, I often think of Aristotle and Plato as being the smartest men to never be correct. I’m no scholar of these Greek thinkers, and I do hold them in high esteem. However, they established so many incorrect ideas, that it’s hard to recognize their value when looking at the details.

How should one examine this question? “Where does life come from?”

Francesco Redi challenged it in the 17th century by demonstrating that, yes, meat left out will be ripe with maggots the next day if left alone and undisturbed. However, if that meat is protected from flies, the maggots do not appear.

I don’t like getting my students hung up on dependent and independent variables. Instead, we just talk about controls and what the data means if you get one result or another. In this experiment, I focus on how Redi had to repeat the uncovered meat experiment and demonstrate that he saw maggots. If he could not do that, then it would be meaningless if he also did not see them appear in his experimental condition.

We made a big jump to the same type of experiment done extraordinarily well by Louis Pasteur using his Col de Cygne. Again, my focus is on the controls – Pasteur uses a broth that he shows is capable of growing micro-organisms. He then boils the broth to sterilize it… and here’s the important part – he demonstrates that he can STILL grow micro-organisms in it.

Only then does he show that he can inoculate his broth with microbes by snapping the flask’s neck or tilting it to admit the organisms that have settled in the neck of the flask. In my class, it is the method and the controls that are important. I think most of my students already believe that microbes don’t come from nowhere, they just don’t know why.

We progressed through the review quickly from here. We had already talked about these ideas, we were just organizing them in our minds well.

I reminded them of cell theory and germ theory (what Pasteur and others were addressing in their experiments) I also told them that we were looking forward to talking about the central dogma and inheritance/ evolution.

Then we came around to that quote. Science gives us tools, but it doesn’t tell us how to use them or even whether we should use them.

“By the way… if there was an island of cloned dinosaurs, I’d be first in line to see them,” I said. Sure that’s something of a moral question. But we have better ones:

  1. Is medicine good for us? What does it do to the population?
  2. Should we be genetically modifying organisms? What about rice –  to make it more nutritious and therefore able to support more people?
  3. What about gene therapy?
  4. What about cloning?
  5. What about stem cells?

I talked briefly about a lot of these topics, but I also reminded them that I only had opinions like everyone else. Sure, I think mine are right, but not because I’ve studied more science than them. They needed to be educated in order to make decision, but their education wouldn’t tell them what was right or wrong.

That’s a wrap. I talked about a few other things, but mostly, chapter one is fluff – stuff to prime your mind to think about biology, but not a whole lot of actual material to learn.

We’re having a quiz on Tuesday on some things that I spelled out explicitly.

Then we took the briefest possible look at chapter two: Chemistry

Saying the word “Chemistry” gets a lot of people cringing and squirming in their seats. “Why do we have to learn chemistry in this class?” (to be truthful, that’s something I hear every year, but didn’t actually hear this year).

“Because,” I said, “Physics is the rules for how the universe works, chemistry is the physical manifestation of those rules and biology is the life that emerges from that chemistry.”

Next time… what a biologist can teach about chemistry (it’s not much, but it’s enough to get us rolling)


Note: I’m using quotations here and there only to frame an argument, not to suggest that these actual words came from the speakers.

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Posted by on August 24, 2012 in Education


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