West of Nothing

39. The Long and the Short

Starting with the short strands of SDNA, Gabby wrote, we can be fairly certain they serve the same role as human DNA, except it only takes one base to spell an amino acid, owing to all the extra codes.

"We already come to this conclusion," Johnny said a touch peevishly. He didn't appreciate being lectured on his own field.

Did you know about the meta-instructions? Gabby asked.

Johnny folded his arms over his chest but remained silent.

The short-SDNA is even smaller than compression can account for. Simply put, it can't contain enough genes to run the cellular machinery. The most likely explanation is that some of the bases are used for control rather than coding purposes.

"Like stop codon," Johnny said. "That marks where one gene ends and next begins."

Right. Except with a larger vocabulary of instructions like skip, repeat, jump to this other position, and so on. They can be chained together in combination to form commands like jump forward by eight positions, repeat five times, then return home. In this way, complex proteins can be spelled out using a library of shorter segments.

"So it contains both the code and the program to run it," HotDamn said. "Sort of like a genetic applet."

That's a good way of putting it.

"When do you become such expert on DNA?" Johnny said with begrudging respect.

Freckleface has been filling me in. Freckleface was the nickname they had given to Scottie Ermacher, the Axolotl lab tech who was now an honorary member of the X-Bot team. I don't know diddly about DNA, but he convinced me it was all about information encoding, and that's a subject I do happen to know a fair bit about. I got a lot of help from the hacker community too.

"You posted the information on your blog?" Mason asked. "Isn't that against the rules?"

Not if the major gives you the all clear. Besides, unless you know where it came from, it's just another data set containing strings of letters and numbers.

"And what did your programmer friends have to say about the long-SDNA?" HotDamn asked.

This is where things really get interesting, Gabby wrote. Unlike the short kind, it's not correlated to amino acids.

"If it's not for genes, then what's it for?" Mason asked.

What indeed? And why is there so much of it? A typical long-SDNA strand is over a trillion base pairs and we estimate the X-Bot contains somewhere in the neighborhood of a few million of them—all unique. It's almost obscene when you think about it. That's enough storage to hold the entire YouTube library.

"That's a whole lot of porn," Mason remarked.

Corny shot him a glare. "What kind of data could take up that much space?"

Peeper may not be far off, though the subject matter is probably more PG-rated. We believe the long-SDNA is for storing multi-media information.

"Multi-media?" Mason said. "As in video and sound? How can you tell that?"

Information theory. It goes back to the work of Claude Shannon and the early cryptographers. In any language, the distribution of symbols will follow similar statistical patterns based upon the nature of the information it encodes. Take an ordinary MP3 music file. Regardless of whether it's Mozart or Eminem, it shares many properties in common like the modulation of sound waves and rhythmic repeats. This creates a telltale signature. The same is true for visual data. When we compare the patterns of audio and visual files to certain stretches of the X-Bot's long SDNA, we find striking similarities.

"The perfect surveillance device," Skunkworks said. "It records a bug's eye view of everything it sees and hears. What about the other non-matching parts?"

We suspect they encode for other modalities like smell and body position, but we're just speculating here since we don't have universal formats for these.

"What does it use all that information for?" Corny asked. "Can it even access the long-SDNA once it's been made?"

"I am not thinking so," Johnny broke in. "Short-SDNA is free-floating in nucleus. On the opposite hand, long-SDNA is bound up in chromatin like in tight coat for crazy person—what you call that?"

"Straitjacket," Mason said. "So it's just filed away then?"

Looks that way. Write once and read only. Like a DVD.

"Looks like we found its data bank," Skunkworks said. "So where's its brain?"

"Maybe in dense material behind eye-band or in eyeball itself," replied Johnny. "Not take sample of this tissue, too dangerous."

"And those salt-like specks? Could those be mini-microprocessors—what did you call them?"

Compu-dots, Gabby filled in.

Johnny shook his head. "Analysis show they contain nutrients and minerals. We think they serve as cache, like vitamin pill."

HotDamn thoughtfully kneaded his jaw. "There's a lot we still don't know about this thing."

We know it sees and thinks, said Gabby. And now we know it remembers.