Dark Ararat - Brian Stableford [48]
“As you can see,” he went on, “one of the molecules is a double helix that codes for proteins in a fashion roughly similar to that of DNA, although it’s a little more versatile. We call it meta-DNA, but that’s just for temporary convenience. There are too many viable molecules in what we now recognize as the DNA-para-DNA-meta-DNA family to be discriminated by the customary tags—doubtless we’ll eventually work out a whole new terminology, and maybe a whole new branch of science.
“The second molecule, here, is the oddity: a freak whose like hasn’t yet been encountered anywhere else. All the coder-replicators in the DNA family are basically two-dimensional structures, even though they’re twisted repeatedly in order to wind them up into compact structures like plasmids and chromosomes. As you can see”—here Lityansky animated the image on the screen so that the second molecular model began to rotate—“Ararat’s second coder-replicator is three-dimensional even at the most basic level of structure. We thought at first that it was tubular, like the more complicated buckyball derivatives, but those are just carbon complexes with occasional add-ons, and this has other components that are far more complex. The amplifications are mostly nitrogen, hydrogen, and oxygen, as you’d expect, and you won’t be unduly surprised by the phosphate residues—but look at the silicon and the lanthanides! You’ve never seen anything remotely like them.
“The silicon was an almost-expectable shock, I suppose, because we’ve always preset our probes to search high and low for traces of silicon or silicone-based life, both in and outside the home system. We never found any, but we kept hoping. Even running across silicone-like formations working in collaboration with rare earths as well as carbon didn’t seem so very surprising in retrospect, in view of the way that nanotech development has proceeded on Earth since we’ve been away. There’s been a dramatic convergence of the organic and the inorganic at what more recent jargon calls the picotechnological level, and the inorganic materials involved in the convergence are the descendants of the old silicon chips and modular doping arrays—but that’s artifice too. This is natural, although I ought to admit that there are some mavericks on the surface who aren’t entirely convinced.”
“Why not?” Matthew asked, wondering whether the “mavericks” in question included Bernal Delgado.
“Because they’re excessively impressed by the fact that this world is a billion years older than Earth. They’re not convinced that evolution happened here at a much slower rate. They wonder whether there might have been an advanced civilization here at one time: one as advanced as Earth’s. If so, they argue, it too might have developed artificial coding systems for biotechnological and nanotechnological purposes. Personally, I find it impossible to believe that any such civilization wouldn’t have left more obvious relics.”
“After a billion years?” Matthew countered.
“A sophisticated inorganic technology ought to have left some identifiable traces,” Lityansky insisted. “There’s no evidence of any such traces on the surface. Anyhow, the situation now is that Ararat’s second coding molecule is associated with a whole new sideline of organic chemistry, which collaborates with the one that’s a close analogue of Earthly organic chemistry. Given that fundamental collaboration, maybe it isn’t so surprising that we also find biochemical collaborations of a much more adventurous kind.
“With the aid of hindsight, perhaps it isn’t so unusual that all the metazoan cells in the Ararat ecosphere have two differently based genomes. After all, you and I and all our animal cousins have two genomes too, although the nuclear genome and the mitochondrial genome are both DNA-based. Collaboration between genomes is obviously possible, given the Earthly example, so it’s not such a huge stretch of the