Thursday, January 5, 2017

No straight lines

One of the things I really want to get across to my students is that the way scientific, and especially biological concepts are depicted is not necessarily the way they are. We tend to get our impressions of how things look from textbooks or from simple image searches. These reflect decades or sometimes centuries of misapprehension. I learned this when I was doing my doctoral work in botany at Harvard and found textbook and scientific images that hailed from medieval depictions of plants that themselves had their source in antiquity! 

While I first learned this lesson as a highly focused graduate student with the world's greatest botany library at his fingertips, I'm thinking a little more generally here. For example, in cells there are no straight lines. But you see straight lines in all kinds of depictions. They connote more than just straight lines. They suggest "solidity" and permanence, conditions that are very rare (if they occur at all) in the cellular environment. Similarly, atoms and molecules are shown with straight lines depicting bonds. Obviously in real life there are no lines there at all. And the bonds of course are invisible, just like the molecules themselves. But as a students (and teachers I think) we tend to take them as a given and come to understand the properties of scientific phenomena within these pre-determined and highly limiting confines. 

The same as there are no straight lines, there is really no "up" or "down" in living systems. Of course there is the force of gravity and this influences structure and function, especially in tissues and organisms, but really, do the organisms have an "up" and a "down" or do they just experience them? Similarly, biological molecules of all sorts are depicted with a "top" and a "bottom." If you look critically at the biological world you see that molecules are not limited in this way. Neither are unicellular organisms. In multi-cellular organisms cells in aggregation are a kind of colloid body within the colloidal medium of tissues. So there is no "up" or "down" there. Just a kind of floating. Even larger organisms, while clearly polar (they have a top and a bottom) are simply organizing their cells and tissues in response to light and/or a perceived gravitational pull. This is obvious in highly plastic organisms like fungi, but it's the case in more "differentiated" organisms as well. Put a plant on its side and it will grow quite well. It will respond to light by growing "upward" shoots and it will respond to soil by growing roots "downward" but the plant can also grow quite successfully upside down. What about in our species? Does a fetus in utero have a particular orientation? If the head is pointed downward is that still the top?

These questions may seem absurd but I think it's important to encourage my students to look in new ways at the world of biology. Not necessarily to understand biology better but to get a new fresh look at their world. 

Our first exercise of the semester will be to construct a model in which there are no straight lines. We'll use Zometools to do it. If you haven't seen these amazing teaching devices you should look them up when you get a spare moment. Each lab group will build what turns out to be an uneven planar surface. It turns out there are lots of scientific applications to this problem. I think there are philosophical implications as well. We'll build table-sized sculptures and then play around then with some questions like, how would water flow on this surface or, how would light move from one point to another along this surface? I'm hoping that students will see patterns in the planar shapes they build. For example if they use repeating same-shapes put together versus random varying shapes how will their creations differ?

I was never taught this kind of exercise in any biology class and I wonder where and if things like this are being taught. It's simple but I think it's also, literally, a kind of rocket science. This is a kind of thinking that may go over the heads of my second-year undergraduates but I see our labs as a kind of incubator for new kinds of thinking that may find their way to other settings. Is it worth it to get students to think outside of the box in this way? Will it influence the way they come to understand the lecture material? Most important, will it help them conceptualize in an abstract way ideas, situations, and structures that they encounter in their future work outside of the classroom?

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