I have been thinking a lot lately about the stuff of life.  No, not single-malt Scotch, but DNA. I just finished re-reading a very interesting Robin Cook novel called “Mutation,” in which a physician entrepreneur and researcher meddles with his own unborn son’s genes with terrifying results. Genetics are not my area of expertise, but who could not be fascinated by the sheer complexity and power of this amazing molecule in the shape of a double helix? It’s a biological computer program, written in a language unique to life, and we understand less than 5% of the code as of now.

An episode of “House, M.D.” last night brought DNA back into my mind, and for some reason I could not remember the word for the sequences of DNA that fall between the genes and are not replicated during transcription. The word totally escaped me, and I refused to look it up as a matter of pride, so I kept trying to think of it for the rest of the evening until I fell asleep.

When I awoke this morning, I got up, drank some lemonade, gave the dog a treat, and suddenly remembered that the word was “introns.” I suppose that the dog, the lemonade, or the orthostatic hypotension could have separately or collectively caused my memory to disgorge the information; who can say? I immediately texted this word to Allison, who had also been trying to remember it. She responded by calling me a “sexy geek,” which made my day.

Today I found myself sitting down to lunch with nothing to read. That’s fairly unusual for me, since if I’m eating alone, I generally have some reading material at hand to keep my mind occupied while I attend to the needs of my body. I’ve read novels, industry periodicals, nonfiction, and even product literature over lunch in the past, but today my quick search turned up nothing of interest. So, I sat down and simply ate.

I’d been eating for only five or ten minutes before my mind began to wander. In the restaurant, two television sets were on and tuned to CNN and Fox News. The only “news” was political, and this probably contributed to my bored, desperate turn toward my inner mind for entertainment. I thought about DNA again, and its helical structure, and remembered something I’d read in the Feynman Lectures on Physics years ago.

Feynman did one entire lecture on the symmetry of the physical laws. We assume all of our physical laws to be symmetrical. Symmetry can be explained in a really simple way. If you can take something (an object or an intangible) and do something to it (rotation, reflection, translation, etc.) and it looks the same as it did before, that thing is said to have symmetry.

I remember that Feynman used an odd example that really set my mind in motion. I’m going to do a terrible job of re-describing it and I don’t have the books at hand, so bear with me.

Say we make a solution of common sugar in water. We then shine a polarized light source through that sugar solution and observe the light on the other side. We will notice that the plane of polarization of the light has been rotated from the original, and that it has rotated to the right.

Now let’s hypothetically synthesize some sugar artificially. It’s not hard to do, but we won’t go into the process here. We’ll dissolve that sugar in water, and shine the same polarized light into it. Oddly enough, we discover that the light’s polarization hasn’t rotated at all!

Now, let’s add some bacteria to the water and let them eat some of the sugar. After a few minutes, we’ll then shine the light through the container again. Wait a minute! The light exiting the container has rotated now, all right — but to the LEFT!

What happened? The natural sugar rotated the plane of polarization to the right because natural sugar — glucose, in particular a form of glucose called dextrose or d-glucose, has a right-handed helical structure. When we created our synthetic sugar, we made something with the right chemical formula, but it actually contained equal parts of d-glucose (dextrose) and l-glucose, which is left-handed! The rotations cancelled and we saw no effect until we added bacteria. All life that we’re aware of, right down to bacteria, either produces or uses right-handed sugar molecules. The bacteria ate only the d-glucose, having no use for the l-glucose since it can’t be broken down for use as food because the enzymes don’t fit! We were then left with an l-glucose solution that rotated the plane of polarization to the left.

This started a thought process that began with left-handed sugars and went rather awry, with amusing consequences. I began to realize that because of the symmetry of physical laws, it is entirely possible that all life on earth could have come to be the opposite way. Almost everything in nature that has a helical structure rotates to the right. What if somewhere, somehow, life either evolved or was created that was based on all left-hand structures?

An interesting idea for a science-fiction premise began to form in my mind.  Complications are what make fiction interesting, after all. Edwin A. Abbott took away one dimension and came up with a whole world called Flatland. What if we created a world that hosted a majority of normal, right-hand-helix humans like us, and a minority of left-handed-helix humans based on Z-DNA? We could call them Leptans, and the circumstances of their life would be most interesting.

To a Leptan, most of the foodstuffs on earth would be essentially non-nutritive. Leptans would have enzymes that can only break down left-handed sugars, and to construct their proteins they would require left-handed amino acids that also aren’t found in nature in any significant quantity. Food for leptans would have to be synthetic, since a cannibalistic population could not be self-supporting and would die out quickly.  

Interaction between leptans and humans would be unusual. A leptan and a human could probably not produce offspring, because their DNA would not fit together and could not be combined during meiosis. How a human body might react to “contamination” from a leptan body cell, or vice-versa, is something I can only speculate upon, lacking the knowledge of genetics and immunology to actually analyze the possibilities. There could easily arise unique and unprecedented problems with leptans and humans living in close proximity.

Would leptans grow to resent the majority of humans? Would they come up with ugly, racial slur-like names for us, like “dexters?” Would there eventually be a leptan uprising, with the leptans releasing some horrible enzyme or toxin that’s fatal to humans but to which leptans are immune? Would the majority of leptans turn out to be left-handed in terms of manual dexterity, and would the functions of their two brain hemispheres be reversed, or is that not the result of a symmetrical physical law?

Leptans would almost certainly be a better-looking, healthier people than humans. When all food has to be produced via very expensive synthetic means, I don’t think gluttony would be a big problem. If a leptan did find himself getting a little porky, he need only turn to the food of humans. He could eat at Dunkin Donuts every day and never gain a pound, because his body could not process the sugar.

There seemed to be no end to the interesting premises associated with the leptan race, and I spent the rest of my lunchtime thinking about this. I think it’s a great idea, and I’d love it if someone ran with it. At the very least it’d make a good “Twilight Zone” episode, but it could easily be fleshed out into either a movie or a full TV series. “Leptan Uprising” even sounds like a really good name for a video game. If you make your first million selling this idea to Spielberg or NBC or Nintendo, please be so kind as to give me some small credit. I haven’t quite figured out how to “copyleft” the notion. 🙂