When the door closed behind her, Solari said: “Anything I should know?”

“Not urgently,” Matthew assured him. “It was a personal thing. I know Shen. I owed it to him to pay my respects, whatever the effort required. The crew don’t understand how much they owe him.”

“That’s the way it is with children of a revolution,” Solari observed. “They tear up the past, demonize the ancestors they used to worship. But when they’ve tried out the extremes for size, they usually swing back. The wheel tends to come full circle—that’s why they call them revolutions.”

Matthew wasn’t sure that was true, but he hadn’t the energy to argue, or even to reply. As soon as silence fell, he was asleep.

TWELVE

Andrei Lityansky was as tall and slim as the majority of the crew, but his skin was too dark to manifest the curious greenish tint that many of his fellows displayed. The cast of his features was slightly Semitic—a point of Earthly reference that Matthew found oddly reassuring—and his hair was jet black. He wore a neat triangular beard, the first one Matthew had seen on Hope.

Matthew had hardly had time to finish his unappetizing breakfast before Riddell had turned up to guide him to his appointed rendezvous, but Lityansky didn’t look like a man who had recently woken from refreshing sleep. He seemed a trifle fractious, like a man who did not appreciate the disturbance of his expectations by the kind of unexpected delay that Matthew had imported into his schedule. He was nursing a cup of what looked like coffee, but he didn’t offer any to Matthew.

“How is Shen Chin Che?” the crewman asked, with ostentatious irony. “We haven’t seen much of him lately.”

“As well as can be expected,” Matthew replied. “How are Captain Milyukov and the man I hit?”

“The captain’s untroubled. He had no intention of keeping any secrets from you. There was no need for you to seek out the renegades—as you must have discovered. Lamartine’s broken jaw will heal, but the other damage might be more serious.” Matthew took the second remark to imply that Lityansky had heard the tape of his conversation with Shen. The last sentence was more worrying, but he didn’t want to discuss the crew’s ambivalent attitudes to their passengers. He wanted to hear what Lityansky had to say about the ecosphere of the new world; and its underlying genomics.

Lityansky understood that, but he had his own order of priorities. He insisted on “putting the information in context,” perhaps because he thought it necessary and perhaps because he wanted to inflict a little subtle punishment on Matthew for screwing up his schedule.

“You might have heard mention of a life-bearing orphan planet that we passed close by two hundred years ago,” the biologist said. “We’ve had reports from Earth’s robot probes of two others, and of half a dozen life-bearing planets in solar systems closer to Earth than this one. That knowledge had already informed our grandfathers, long before we arrived here, that the panspermists and the more extreme convergence theorists were wrong. DNA isn’t the only basis of life to be found in the galaxy, and doesn’t appear to be common. Perhaps one coding molecule will eventually win the cosmic struggle for existence by out-competing all its rivals, but that certainly won’t happen soon—and by soonI mean any time in the next few billion years. Everything we have so far discovered suggests that we live in a galaxy in which life is very various.”

“But most of the rivals to DNA you’ve so far discovered,” Matthew put in, “aren’t capable of producing anything but bacterial sludge.”

“We don’t know that,” Lityansky said. “DNA probably couldn’t produce anything but bacterial sludge in the context of an orphan planet, and we’ve no reason to think that any of the alternative coding molecules present on such worlds would be incapable of producing complex life if they had the resources of a sunlit planet like Earth or Ararat to work with. It might, of course, be unreasonably arrogant of us to think of such worlds as the primary abodes of life or as the highest achievements of evolution. It is at least conceivable that one of the many kinds of bacterial sludge that exist in less balmy conditions will ultimately out-compete everything else, proving that metazoan creatures—including sentient humanoids—are merely temporary follies of creation.”

“Fair enough,” Matthew said. “So tell me about temporary folly number two.”

“I think you’ll find it intriguing,” Lityansky told him, teasingly. “Until we arrived here, everything we had learned from our own orphan and the data harvested from Earth’s probes suggested that there was one candidate rule of comparative evolution that seemed to have held firm. In all the other cases known to us, each ecosphere had only one fundamental reproductive molecule—DNA and RNA aren’t sufficiently different, of course, to be reckoned fundamentally different. The coding molecules were all different, but each ecosphere was derived from a single biochemical ancestor. Earth is now a partial exception to the rule—the news from home says that Earthly biotech has been enhanced by a whole new range of artificial genomic systems based on a molecule whose primary version was dubbed para-DNA—but that was the result of clever artifice. Ararat is a genuine exception: a naturalexception.

“The inference we had taken from the fact that each new ecosphere had only one fundamental coder-replicator was that in any limited arena, one reproductive molecule would be bound to win out over all others in a primordial competition—a biochemical variant of that discredited pillar of primal ecology, Gause’s axiom. That axiom can now be discounted at the biochemical level as well as the specific level. Here on Ararat there are two fundamental reproductive molecules, whose competition has been resolved in a rather peculiar way.”

“Go on,” Matthew prompted, when Lityansky paused—but he had paused for a reason, to use a keypad to summon a set of formulas and molecular models to the wallscreen behind him.

“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. Thisis natural, although I ought to admit that there are some mavericks on the surface who aren’t entirely convinced.”