Letter From The Editor - Issue 69 - June 2019

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  Science Fact-ion by Randall Hayes
October 2015


How is a spider like a cotton plant? How do we know, just from looking at the shapes of its teeth, what an animal eats? Architects like to say "form follows function," but that's backwards to a scientist. We say "function follows form." Look carefully at any structure, at the right level of magnification, and how that structure works - what it's good for - will be revealed.

When my mom went to college in the late 1950s, Biology 101 consisted mostly of nature study, cataloguing and often drawing the adaptations of plants and animals to the places they live, in terms of the shapes of their bodies - narrow leaves conserve water, broad leaves capture more light, things like that. The Krebs cycle was for premed students taking biochem. These days, even non-majors are expected to memorize the basics of glucose metabolism and photosynthesis. Many of them forget it after the exam, of course, but I think all this cellular fooforah has had some good influence on a generation of Americans. They at least know that molecules exist, and that molecules are the basis of all the drugs we take.

Unfortunately, I find that the current focus on memorizing molecular details means that most students, and many SF writers, have missed the point. They don't seem to understand at an intuitive level how biochemistry actually works, and this limits their use of it to technobabble about genes and DNA (an exception is this Escape Pod story, which also mentions functional groups from Organic I). The most basic concept in biochemistry is shape. Every molecule is assembled out of atoms like Lego bricks. The unique 3D shape of each assembly gives the resulting molecule its particular function. Fibers are made of long molecules that cross-link to form braided ropelike structures. It doesn't matter that cellulose is made from sugars by plants, or that silk is made from proteins by insects, spiders, and transgenic goats. The important part is the structure of long cross-linked chains (in the picture to the right of that news release, the red and purple chains are bonded by yellow cross links). The structure determines the properties.

Because they are too small to see directly, it helps to understand these things through analogy and simulation. Compare the Thunderdriller, which my son built from a Lego kit when he was about 8, to the enzyme "motor" that makes ATP embedded in the inner membrane of the mitochondrion.

They are both pretty complex. There are gears that connect the wheels of the Thunderdriller to the huge drill bit on the front, so that when a child (or a childlike Ph.D.) rolls it across the floor, the forward motion of the wheels spins the drill bit. I've never checked, since my son long ago cannibalized the parts for other building projects, but I'll bet backwards motion would spin the drill bit in the opposite direction. The same thing can happen with ATP synthase! This is just one example of the much broader concept that function follows form. Most toxins, most drugs, most disease organisms, have their effects through mimicking the shape of some molecule produced inside the body. Imperfect mimics can have interesting side effects, as they bind to their targets with a different strength than the original, or bind to the wrong target, or even to more than one target.

In other words, most of a writer's social intuitions about deception and betrayal apply to some extent even at the cellular level!

Nothing is free, of course. The increasing sophistication of college students and writers about cells and molecules means that they spend much less time studying ecology and natural history. Worse, they believe that these subjects have nothing to do with one another! I was reminded how common this problem is during a trip to Glacier National Park this summer. We went on several ranger-led hikes, one of them with a geologist named Tegan, who I can only assume was named for the Dr. Who companion. She was a total Time Lord, brilliant at pointing out the connections between "different" fields of science, which is rare. Most of what the Ranger said seemed new to the people on the hike, including me, who made it through a biology major without ever taking a geology class.

At the very beginning of our trek up to Avalanche Lake, Ranger Tegan showed us a billion-year-old stromatolite (looking sort of like a brain coral, but built by bacteria). She used the 1989 Loma Prieta earthquake, which flattened her hometown of Santa Cruz, to dramatize the slow collision of the tectonic plates that broke the earth's crust and raised those buried relics up to where we can see them. She asked our tour group to read the story of an avalanche, which had stripped the side of the valley where it started almost to bare rock; at the bottom of the valley it had snapped trees off at the level of the standing snowfall (about 20 feet!); and on the opposite side of the valley, the pressure of the air being pushed by the falling wall of snow had been enough to knock trees over uphill, like pictures you may have seen of an atomic blast, or the Tunguska explosion. By looking at the structure of the scene in front of us, we could determine what had happened.

It was quite a morning, overall, even before she saved us from the bear.

Not with a gun - not even with bear spray (molecule, molecule, molecule!). She just applied principles of animal behavior. We made enough noise to let the bear know where we were, that there were a lot of us, and that we weren't going to start any trouble. See, animals, especially predators, are not stupid. They are not mindless video game sprites, charging anything that enters their aggro radius. Most importantly, they don't stand next to you and trade shots until someone's health bar runs out. This is from a book of Theodore Roosevelt's bear-hunting essays, which I found on the shelf at my in-laws' home in Montana on that same trip:

"A bear is apt to rely mainly on his teeth or claws according to whether his efforts are directed primarily towards killing his foe or to making good his own escape. In the latter event he trusts chiefly to his claws . . . In such a case he usually strikes a single blow and gallops on without halting, though that one blow may have taken life. If the claws are long and sharp (as in early spring, or even in the fall, if the animal has been working over soft ground) they add immensely to the effect of the blow, for they cut like blunt axes . . . If a bear means mischief and charges not to escape but to do damage, its aim is to grapple with or throw down his foe and bite him to death."

This is a whole other level of detail and realism (but still, function follows form). I've often heard SF writers say that they write dystopias because conflict drives the story. Ironically, I've equally often heard writers say that they hate writing combat, because it's so boring, because all combats are the same. Those writers could seek inspiration from other fields of literature, like natural history.

The same basic principles unite all of science, despite the politics of professional and educational "disciplines." SF is a prime place to show that integration.

Randall Hayes also organizes the Greensboro Science Cafe series and runs his own education company, Agnosia Media, LLC. In between columns, keep up the discussion on PlotBot's new Facebook page.






The ATP synthase enzyme starts at about 1:10.



"Science in those days worked in broad strokes! They got right to the point! Nowadays it's always molecule, molecule, molecule . . ."


My in-laws are fairly generous people, but you'll probably have better luck finding this at your local library.



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